SQLJ Developers Guide

Oracle® Database
SQLJ Developer's Guide
Release 21c
F31394-01
December 2020
Oracle Database SQLJ Developer's Guide, Release 21c
F31394-01
Copyright © 1999, 2020, Oracle and/or its affiliates.
Primary Author: Apoorva Srinivas
Contributing Authors: Tanmay Choudhury, Tulika Das, Venkatasubramaniam Iyer, Brian Wright, Janice
Nygard
Contributors: Krishna Mohan, Amit Bande, Sumit Sahu, Amoghavarsha Ramappa, Dhilipkumar Gopal,
Quan Wang, Angela Barone, Ekkehard Rohwedder, Brian Becker, Alan Thiesen, Lei Tang, Julie Basu, Pierre
Dufour, Jerry Schwarz, Risto Lakinen, Cheuk Chau, Vishu Krishnamurthy, Rafiul Ahad, Jack Melnick, Tim
Smith, Thomas Pfaeffle, Tom Portfolio, Ellen Barnes, Susan Kraft, Sheryl Maring
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Contents
Preface
Audience xv
Related Documents xv
Documentation Accessibility xvi
Conventions xvii
1 Changes in This Release for Oracle SQLJ Developer’s Guide
2 Getting Started
2.1 Assumptions and Requirements 2-1
2.1.1 Assumptions About Your Environment 2-1
2.1.2 Requirements for Using the Oracle SQLJ Implementation 2-2
2.1.3 SQLJ Environment 2-2
2.1.4 Environment Considerations 2-3
2.1.5 SQLJ Backward Compatibility 2-3
2.2 Checking the Installation and Configuration 2-4
2.2.1 Check for Availability of SQLJ and Demo Applications 2-4
2.2.2 Check for Installed Directories and Files 2-4
2.2.3 Set the Path and Classpath 2-4
2.2.4 Verify Installation of the sqljutl Package 2-5
2.3 Testing the Setup 2-6
2.3.1 Set Up the Run-Time Connection 2-7
2.3.2 Create a Table to Verify the Database 2-7
2.3.3 Verify the JDBC Driver 2-8
2.3.4 Verify the SQLJ Translator and Run Time 2-8
2.3.5 Verify the SQLJ Translator Connection to the Database 2-9
3 Introduction to SQLJ
3.1 Overview of SQLJ 3-1
3.2 Overview of SQLJ Components 3-2
iii
3.2.1 SQLJ Translator Functionality 3-2
3.2.2 SQLJ Run Time 3-3
3.3 Overview of Oracle Extensions to the SQLJ Standard 3-3
3.3.1 SQLJ Type Extensions 3-4
3.3.2 SQLJ Functionality Extensions 3-5
3.4 Basic Translation Steps and Run-Time Processing 3-6
3.4.1 SQLJ Translation Steps 3-6
3.4.2 Summary of Translator Input and Output 3-8
3.4.2.1 Translator Input 3-9
3.4.2.2 Translator Output 3-9
3.4.2.3 Output File Locations 3-10
3.4.3 SQLJ Run-Time Processing 3-10
3.5 SQLJ Sample Code 3-11
3.5.1 SQLJ Version of the Sample Code 3-11
3.5.2 JDBC Version of the Sample Code 3-13
3.6 Alternative Deployment Scenarios 3-14
3.6.1 Running SQLJ in Applets 3-14
3.6.1.1 General Development and Deployment Considerations 3-15
3.6.1.2 General End User Considerations 3-15
3.6.1.3 Java Environment and the Java Plug-In 3-15
3.7 Alternative Development Scenarios 3-16
3.7.1 SQLJ Globalization Support 3-17
3.7.2 SQLJ in Oracle JDeveloper 10g and Other IDEs 3-17
3.7.3 Windows Considerations 3-17
4 Key Programming Considerations

4.1 Selection of the JDBC Driver 4-1
4.1.1 Overview of Oracle JDBC Drivers 4-1
4.1.2 Driver Selection for Translation 4-4
4.1.3 Driver Selection and Registration for Run Time 4-4
4.2 Connection Considerations 4-5
4.2.1 Single Connection or Multiple Connections Using DefaultContext 4-6
4.2.2 Closing Connections 4-9
4.2.3 Multiple Connections Using Declared Connection Context Classes 4-10
4.2.4 More About the Oracle Class 4-11
4.2.5 More About the DefaultContext Class 4-12
4.2.6 Connection for Translation 4-15
4.2.7 Connection for Customization 4-15
4.3 NULL-Handling 4-16
4.3.1 Wrapper Classes for NULL-Handling 4-16
iv
4.3.2 Examples of NULL-Handling 4-17
4.4 Exception-Handling Basics 4-18
4.4.1 SQLJ and JDBC Exception-Handling Requirements 4-18
4.4.2 Processing Exceptions 4-19
4.4.3 Using SQLException Subclasses 4-20
4.5 Basic Transaction Control 4-21
4.5.1 Overview of Transactions 4-21
4.5.2 Automatic Commits Versus Manual Commits 4-22
4.5.3 Specifying Auto-Commit as You Define a Connection 4-22
4.5.4 Modifying Auto-Commit in an Existing Connection 4-23
4.5.5 Using Manual COMMIT and ROLLBACK 4-23
4.5.6 Effect of Commits and Rollbacks on Iterators and Result Sets 4-24
4.5.7 Using Savepoints 4-25
4.6 Summary: First Steps in SQLJ Code 4-26
4.7 Oracle-Specific Code Generation (No Profiles) 4-31
4.7.1 Environment Requirements for Oracle-Specific Code Generation 4-31
4.7.2 Code Considerations and Limitations with Oracle-Specific Code
Generation 4-32
4.7.3 SQLJ Usage Changes with Oracle-Specific Code Generation 4-33
4.7.4 Advantages and Disadvantages of Oracle-Specific Code Generation 4-34
4.8 ISO Standard Code Generation 4-35
4.8.1 Environment Requirements for ISO Standard Code Generation 4-35
4.8.2 SQLJ Translator and SQLJ Run Time 4-36
4.8.3 SQLJ Profiles 4-36
4.8.3.1 Overview of Profiles 4-37
4.8.3.2 Binary Portability 4-37
4.8.4 SQLJ Translation Steps 4-38
4.8.5 Summary of Translator Input and Output 4-39
4.8.5.1 Translator Input 4-39
4.8.5.2 Translator Output 4-39
4.8.5.3 Output File Locations 4-41
4.8.6 SQLJ Run-Time Processing 4-41
4.8.7 Deployment Scenarios 4-42
4.9 Oracle-Specific Code Generation Versus ISO Standard Code Generation 4-44
4.10 Requirements and Restrictions for Naming 4-44
4.10.1 Java Namespace: Local Variable and Class Naming Restrictions 4-44
4.10.2 SQLJ Namespace 4-46
4.10.3 SQL Namespace 4-46
4.10.4 File Name Requirements and Restrictions 4-46
4.11 Considerations for SQLJ in the Middle Tier 4-47
v
5 Basic Language Features
5.1 Overview of SQLJ Declarations 5-1
5.1.1 Rules for SQLJ Declarations 5-2
5.1.2 Iterator Declarations 5-3
5.1.3 Connection Context Declarations 5-3
5.1.4 Declaration IMPLEMENTS Clause 5-4
5.1.5 Declaration WITH Clause 5-5
5.1.5.1 Standard WITH Clause Usage 5-5
5.1.5.2 Oracle-Specific WITH Clause Usage 5-7
5.1.5.3 Example: Returnability 5-7
5.2 Overview of SQLJ Executable Statements 5-8
5.2.1 Rules for SQLJ Executable Statements 5-9
5.2.2 SQLJ Clauses 5-9
5.2.3 Specifying Connection Context Instances and Execution Context
Instances 5-11
5.2.4 Executable Statement Examples 5-11
5.2.5 PL/SQL Blocks in Executable Statements 5-12
5.3 Java Host, Context, and Result Expressions 5-13
5.3.1 Overview of Host Expressions 5-14
5.3.2 Basic Host Expression Syntax 5-15
5.3.3 Examples of Host Expressions 5-17
5.3.4 Overview of Result Expressions and Context Expressions 5-18
5.3.5 Evaluation of Java Expressions at Run Time 5-18
5.3.6 Examples of Evaluation of Java Expressions at Run Time (ISO Code
Generation) 5-20
5.3.7 Restrictions on Host Expressions 5-25
5.4 Single-Row Query Results: SELECT INTO Statements 5-26
5.4.1 SELECT INTO Syntax 5-26
5.4.2 Examples of SELECT INTO Statements 5-27
5.4.3 Examples with Host Expressions in SELECT-List 5-27
5.4.4 SELECT INTO Error Conditions 5-28
5.5 Multirow Query Results: SQLJ Iterators 5-28
5.5.1 Iterator Concepts 5-29
5.5.1.1 Overview of Strongly Typed Iterators 5-29
5.5.1.2 Overview of Weakly Typed Iterators 5-31
5.5.2 General Steps in Using an Iterator 5-31
5.5.3 Named, Positional, and Result Set Iterators 5-32
5.5.4 Using Named Iterators 5-33
5.5.5 Using Positional Iterators 5-36
5.5.6 Using Iterators and Result Sets as Host Variables 5-39
5.5.7 Using Iterators and Result Sets as Iterator Columns 5-42
vi
5.6 Assignment Statements (SET) 5-44
5.7 Stored Procedure and Function Calls 5-45
5.7.1 Calling Stored Procedures 5-45
5.7.2 Calling Stored Functions 5-46
5.7.3 Using Iterators and Result Sets as Stored Function Returns 5-47
6 Type Support
6.1 Supported Types for Host Expressions 6-1
6.1.1 Summary of Supported Types 6-2
6.1.2 Supported Types and Requirements for JDBC 2.0 6-6
6.1.3 Using PL/SQL BOOLEAN, RECORD Types, and TABLE Types 6-8
6.1.4 Backward Compatibility for Previous Oracle JDBC Releases 6-9
6.2 Support for Streams 6-9
6.2.1 General Use of SQLJ Streams 6-10
6.2.2 Key Aspects of Stream Support Classes 6-11
6.2.3 Using SQLJ Streams to Send Data 6-11
6.2.4 Retrieving Data into Streams: Precautions 6-14
6.2.5 Using SQLJ Streams to Retrieve Data 6-15
6.2.6 Stream Class Methods 6-17
6.2.7 Examples of Retrieving and Processing Stream Data 6-19
6.2.8 SQLJ Stream Objects as Output Parameters and Function Return
Values 6-21
6.3 Support for JDBC 2.0 LOB Types and Oracle Type Extensions 6-22
6.3.1 Package oracle.sql 6-23
6.3.2 Support for BLOB, CLOB, and BFILE 6-24
6.3.3 Support for Oracle ROWID 6-29
6.3.4 Support for Oracle REF CURSOR Types 6-33
6.3.5 Support for Other Oracle Database 11g Data Types 6-35
6.3.6 Extended Support for BigDecimal 6-35
7 Objects, Collections, and OPAQUE Types

7.1 Oracle Objects and Collections 7-1
7.1.1 Overview of Objects and Collections 7-1
7.1.2 Oracle Object Fundamentals 7-3
7.1.3 Oracle Collection Fundamentals 7-4
7.1.4 Object and Collection Data Types 7-4
7.2 Custom Java Classes 7-5
7.2.1 Custom Java Class Interface Specifications 7-5
7.2.2 Custom Java Class Support for Object Methods 7-7
7.2.3 Custom Java Class Requirements 7-7
vii
7.2.4 Compiling Custom Java Classes 7-11
7.2.5 Reading and Writing Custom Data 7-12
7.2.6 Additional Uses for ORAData Implementations 7-12
7.3 User-Defined Types 7-16
7.4 Strongly Typed Objects and References in SQLJ Executable Statements 7-20
7.4.1 Selecting Objects and Object References into Iterator Columns 7-20
7.4.2 Updating an Object 7-21
7.4.3 Inserting an Object Created from Individual Object Attributes 7-22
7.4.4 Updating an Object Reference 7-23
7.5 Strongly Typed Collections in SQLJ Executable Statements 7-24
7.5.1 Accessing Nested Tables: TABLE syntax and CURSOR syntax 7-25
7.5.2 Inserting a Row that Includes a Nested Table 7-25
7.5.3 Selecting a Nested Table into a Host Expression 7-26
7.5.4 Manipulating a Nested Table Using TABLE Syntax 7-27
7.5.5 Selecting Data from a Nested Table Using a Nested Iterator 7-28
7.5.6 Selecting a VARRAY into a Host Expression 7-29
7.5.7 Inserting a Row that Includes a VARRAY 7-30
7.6 Serialized Java Objects 7-30
7.6.1 Serializing Java Classes to RAW and BLOB Columns 7-31
7.6.2 SerializableDatum: an ORAData Implementation 7-33
7.6.3 SerializableDatum in SQLJ Applications 7-35
7.6.4 SerializableDatum (Complete Class) 7-36
7.7 Weakly Typed Objects, References, and Collections 7-37
7.7.1 Support for Weakly Typed Objects, References, and Collections 7-37
7.7.2 Restrictions on Weakly Typed Objects, References, and Collections 7-38
7.8 Oracle OPAQUE Types 7-38
8 Advanced Language Features

8.1 Connection Contexts 8-1
8.1.1 Connection Context Concepts 8-2
8.1.2 Connection Context Logistics 8-3
8.1.3 Declaring and Using a Connection Context Class 8-4
8.1.4 Example of Multiple Connection Contexts 8-6
8.1.5 Implementation and Functionality of Connection Context Classes 8-7
8.1.6 Using the IMPLEMENTS Clause in Connection Context Declarations 8-8
8.1.7 Semantics-Checking of Your Connection Context Usage 8-9
8.1.8 Standard Data Source Support 8-10
8.1.9 SQLJ-Specific Data Sources 8-12
8.1.10 SQLJ-Specific Connection JavaBeans for JavaServer Pages 8-15
8.1.11 SQLJ Support for Global Transactions 8-18
viii
8.1.12 Connecting to PDBs 8-25
8.2 Execution Contexts 8-25
8.2.1 Relation of Execution Contexts to Connection Contexts 8-26
8.2.2 Creating and Specifying Execution Context Instances 8-27
8.2.3 Execution Context Synchronization 8-28
8.2.4 Execution Context Methods 8-28
8.2.4.1 Status Methods 8-29
8.2.4.2 Control Methods 8-29
8.2.4.3 Cancellation Method 8-30
8.2.4.4 Update Batching Methods 8-31
8.2.4.5 Savepoint Methods 8-31
8.2.4.6 Close Method 8-32
8.2.4.7 Example: Using ExecutionContext Methods 8-32
8.2.5 Relation of Execution Contexts to Multithreading 8-33
8.3 Multithreading in SQLJ 8-33
8.4 Iterator Class Implementation and Advanced Functionality 8-36
8.4.1 Implementation and Functionality of Iterator Classes 8-36
8.4.2 Using the IMPLEMENTS Clause in Iterator Declarations 8-37
8.4.3 Support for Extending Iterator Classes 8-38
8.4.4 Result Set Iterators 8-38
8.4.5 Scrollable Iterators 8-39
8.5 Advanced Transaction Control 8-45
8.5.1 SET TRANSACTION Syntax 8-45
8.5.2 Access Mode Settings 8-46
8.5.3 Isolation Level Settings 8-46
8.5.4 Using JDBC Connection Class Methods 8-47
8.6 SQLJ and JDBC Interoperability 8-47
8.6.1 SQLJ Connection Context and JDBC Connection Interoperability 8-48
8.6.2 SQLJ Iterator and JDBC Result Set Interoperability 8-52
8.7 Support for Dynamic SQL 8-54
8.7.1 Meta Bind Expressions 8-55
8.7.2 SQLJ Dynamic SQL Examples 8-56
8.8 Using Stored Outlines 8-59
8.9 Using Plan Baselines 8-65
8.9.1 Generating Plan Baselines 8-65
8.9.2 Command-Line and Property File Options 8-66
8.9.2.1 plan_baseline 8-66
8.9.2.2 plan_prefix 8-68
8.9.2.3 plan_run 8-69
8.9.2.4 plan_fixed 8-70
8.9.2.5 plan_enabled 8-70
ix
8.9.3 Generated SQL File 8-71
8.9.3.1 Generated SQL File Name 8-71
8.9.3.2 Generated SQL File Format 8-71
8.9.4 Generated Log File 8-72
8.9.4.1 Generated Log File Name 8-72
8.9.4.2 Generated Log File Format 8-72
8.9.5 Generated Java File 8-73
9 Translator Command Line and Options

9.1 Translator Command Line and Properties Files 9-1
9.1.1 SQLJ Options, Flags, and Prefixes 9-2
9.1.2 Command-Line Syntax and Operations 9-10
9.1.3 Properties Files for Option Settings 9-13
9.1.4 SQLJ_OPTIONS Environment Variable for Option Settings 9-16
9.1.5 Order of Precedence of Option Settings 9-16
9.2 Basic Translator Options 9-17
9.2.1 Basic Options for the Command Line Only 9-18
9.2.2 Options for Output Files and Directories 9-23
9.2.3 Connection Options 9-26
9.2.4 Options for Reporting and Line-Mapping 9-35
9.2.5 Options for DMS 9-40
9.2.6 Options for Code Generation, Optimizations, and CHAR Comparisons 9-43
9.3 Advanced Translator Options 9-51
9.3.1 Prefixes that Pass Option Settings to Other Executables 9-51
9.3.2 Flags for Special Processing 9-54
9.3.3 Semantics-Checking and Offline-Parsing Options 9-59
9.4 Translator Support and Options for Alternative Environments 9-66
9.4.1 Java and Compiler Options 9-66
9.4.2 Customization Options 9-72
10 Translator and Run-Time Functionality

10.1 Internal Translator Operations 10-1
10.1.1 Java and SQLJ Code-Parsing and Syntax-Checking 10-1
10.1.2 SQL Semantics-Checking and Offline Parsing 10-2
10.1.3 Code Generation 10-3
10.1.4 Java Compilation 10-7
10.1.5 Profile Customization (ISO Code Generation) 10-8
10.2 Functionality of Translator Errors, Messages, and Exit Codes 10-9
10.2.1 Translator Error, Warning, and Information Messages 10-9
x
10.2.2 Translator Status Messages 10-11
10.2.3 Translator Exit Codes 10-12
10.3 SQLJ Run Time 10-12
10.3.1 SQLJ Run Time Packages 10-13
10.3.2 Categories of Run-Time Errors 10-14
10.4 Globalization Support in the Translator and Run Time 10-15
10.4.1 Character Encoding and Language Support 10-15
10.4.2 SQLJ and Java Settings for Character Encoding and Language
Support 10-18
10.4.3 SQLJ Extended Globalization Support 10-20
10.4.4 Manipulation Outside of SQLJ for Globalization Support 10-24
11 Performance and Debugging

11.1 Performance Enhancement Features 11-1
11.1.1 Row Prefetching 11-2
11.1.2 Statement Caching 11-3
11.1.3 Update Batching 11-10
11.1.4 Column Definitions 11-18
11.1.5 Parameter Size Definitions 11-19
11.2 SQLJ Debugging Features 11-21
11.2.1 SQLJ -linemap Flag for Debugging 11-21
11.2.2 Overview of the AuditorInstaller Specialized Customizer 11-22
11.2.3 Overview of Developing and Debugging in Oracle10g JDeveloper 11-22
11.3 SQLJ Support for Oracle Performance Monitoring 11-22
11.3.1 Overview of SQLJ DMS Support 11-23
11.3.2 Summary of SQLJ Command-Line Options for DMS 11-24
11.3.3 SQLJ Run-Time Commands and Properties File Settings for DMS 11-25
11.3.4 SQLJ DMS Sensors and Metrics 11-26
11.3.5 SQLJ DMS Examples 11-29
A Customization and Specialized Customizers

A.1 More About Profiles A-1
A.1.1 Creation of a Profile During Code Generation A-2
A.1.2 Sample Profile Entry A-2
A.1.2.1 SQLJ Executable Statement A-3
A.1.2.2 Corresponding SQLJ Profile Entry A-3
A.2 More About Profile Customization A-3
A.2.1 Overview of the Customizer Harness and Customizers A-4
A.2.2 Steps in the Customization Process A-4
A.2.3 Creation and Registration of a Profile Customization A-5
xi
A.2.4 Customization Error and Status Messages A-6
A.2.5 Functionality of a Customized Profile at Run Time A-6
A.3 Customization Options and Choosing a Customizer A-7
A.3.1 Overview of Customizer Harness Options A-7
A.3.1.1 Syntax for Customizer Harness Options A-7
A.3.1.2 Options Supported by the Customizer Harness A-8
A.3.2 General Customizer Harness Options A-8
A.3.2.1 Profile Backup Option (backup) A-9
A.3.2.2 Customization Connection Context Option (context) A-9
A.3.2.3 Customizer Option (customizer) A-10
A.3.2.4 Customization JAR File Digests Option (digests) A-10
A.3.2.5 Customization Help Option (help) A-11
A.3.2.6 Customization Verbose Option (verbose) A-12
A.3.3 Customizer Harness Options for Connections A-12
A.3.3.1 Customization User Option (user) A-13
A.3.3.2 Customization Password Option (password) A-14
A.3.3.3 Customization URL Option (url) A-14
A.3.3.4 Customization JDBC Driver Option (driver) A-15
A.3.4 Customizer Harness Options that Invoke Specialized Customizers A-15
A.3.4.1 Specialized Customizer: Profile Debug Option (debug) A-16
A.3.4.2 Specialized Customizer: Profile Print Option (print) A-16
A.3.4.3 Specialized Customizer: Profile Semantics-Checking Option
(verify) A-17
A.3.5 Overview of Customizer-Specific Options A-18
A.3.6 Oracle Customizer Options A-19
A.3.6.1 Options Supported by Oracle Customizer A-19
A.3.6.2 Oracle Customizer Version Compatibility Option (compat) A-20
A.3.6.3 Oracle Customizer Force Option (force) A-21
A.3.6.4 Oracle Customizer Column Definition Option (optcols) A-21
A.3.6.5 Oracle Customizer Parameter Definition Option (optparams) A-23
A.3.6.6 Oracle Customizer Parameter Default Size Option
(optparamdefaults) A-24
A.3.6.7 Oracle Customizer CHAR Comparisons with Blank Padding
(fixedchar) A-26
A.3.6.8 Oracle Customizer Show-SQL Option (showSQL) A-26
A.3.6.9 Oracle Customizer Statement Cache Size Option (stmtcache) A-27
A.3.6.10 Oracle Customizer Summary Option (summary) A-29
A.3.7 Options for Other Customizers A-30
A.3.8 SQLJ Translator Options for Profile Customization A-30
A.4 JAR Files for Profiles A-30
A.4.1 JAR File Requirements A-31
A.4.2 JAR File Logistics A-32
xii
A.5 SQLCheckerCustomizer for Profile Semantics-Checking A-32
A.5.1 Invoking SQLCheckerCustomizer with the Customizer Harness verify
Option A-33
A.5.2 SQLCheckerCustomizer Options A-34
A.5.2.1 SQLCheckerCustomizer Semantics-Checker Option (checker) A-34
A.5.2.2 SQLCheckerCustomizer Warnings Option (warn) A-35
A.6 AuditorInstaller Customizer for Debugging A-35
A.6.1 Overview of Auditors and Code Layers A-36
A.6.2 Invoking AuditorInstaller with the Customizer Harness debug Option A-36
A.6.3 AuditorInstaller Run-Time Output A-37
A.6.4 AuditorInstaller Options A-38
A.6.4.1 AuditorInstaller Depth Option (depth) A-39
A.6.4.2 AuditorInstaller Log File Option (log) A-39
A.6.4.3 AuditorInstaller Prefix Option (prefix) A-40
A.6.4.4 AuditorInstaller Return Arguments Option (showReturns) A-40
A.6.4.5 AuditorInstaller Thread Names Option (showThreads) A-41
A.6.4.6 AuditorInstaller Uninstall Option (uninstall) A-42
A.6.5 Full Command-Line Examples A-42
Index
xiii
List of Tables
5-1 SQLJ Statement Clauses 5-10
5-2 SQLJ Assignment Clauses 5-10
6-1 Type Mappings for Supported Host Expression Types 6-2
6-2 Correlation between Oracle Extensions and JDBC 2.0 Types 6-7
6-3 Plausible values for the for_update option and the corresponding SQL statement 6-33
8-1 Table showing the options and values for generating outlines 8-63
9-1 SQLJ Translator Options 9-2
9-2 SQLJ Support for javac Options 9-9
9-3 Tests and Flags for SQLJ Warnings 9-36
9-4 Oracle Online Semantics-Checkers Chosen by OracleChecker 9-60
9-5 Oracle Offline Semantics-Checkers Chosen by OracleChecker 9-60
9-6 Feature Comparison: Offline Parsing Versus Online Semantics-Checking 9-61
10-1 Steps for Generated Calls, ISO Standard Versus Oracle-Specific 10-6
10-2 SQLJ Translator Error Message Categories 10-11
10-3 JDBC and SQLJ Types and Corresponding Globalization Types 10-21
xiv
Preface
This preface introduces you to the Oracle Database SQLJ Developer's Guide,
discussing the intended audience and conventions of this document. A list of related
Oracle documents is also provided.
This preface covers the following topics:
• Audience
• Related Documents
• Conventions
Audience
This manual is intended for anyone with an interest in SQLJ programming but
assumes at least some prior knowledge of the following:
• Java
• SQL
• PL/SQL
• Oracle Database
Although general knowledge of SQL is sufficient, any knowledge of JDBC and Oracle-
specific SQL features would be helpful as well.
Related Documents
Also available from the Oracle Java Platform group are the following Oracle resources:
• Oracle Database Java Developer's Guide
This book introduces the basic concepts of Java in Oracle Database and provides
general information about server-side configuration and functionality. Information
that pertains to Oracle Database Java environment in general, rather than to a
particular product such as JDBC or SQLJ, is in this book.
It also discusses Java stored procedures, which are programs that run directly
in Oracle Database. With stored procedures, Java developers can implement
business logic at the server level, thereby improving application performance,
scalability, and security.
• Oracle Database JDBC Developer's Guide
This book covers programming syntax and features of the Oracle implementation
of the JDBC standard. This includes an overview of the Oracle JDBC drivers,
details of the Oracle implementation of JDBC 1.22, 2.0, 3.0, and 4.0 features, and
discussion of Oracle JDBC type extensions and performance extensions.
xv
Preface
The following documents are from the Oracle Server Technologies group:
• Oracle Database Development Guide
• Oracle Database SecureFiles and Large Objects Developer's Guide
• Oracle Database Object-Relational Developer's Guide
• Oracle Database PL/SQL Packages and Types Reference
• Oracle Database PL/SQL Language Reference
• Oracle Database SQL Language Reference
• Oracle Database Net Services Administrator's Guide
• Oracle Database Advanced Security Guide
• Oracle Database Globalization Support Guide
• Oracle Database Reference
• Oracle Database Sample Schemas
Note:
Oracle error message documentation is available on Oracle Technology
Network. You can browse the error messages by range. Once you find the
specific range, use the "find in page" feature of your browser to locate the
specific message. When connected to the Internet, you can search for a
specific error message using the error message search feature of the Oracle
online documentation.
For documentation of SQLJ standard features and syntax, refer to the following
specification:
Information Technology - Database Languages - SQL - Part 10: Object Language
Bindings (SQL/OLB)
Throughout this manual, the term "ISO SQLJ standard" is used to refer to this
standard.
You can obtain the ISO SQLJ standard from ANSI through the following Web site:
http://www.ansi.org/
Click eStandards Store and search for the term "INCITS/ISO/IEC 9075-10".
You can also obtain the ISO SQLJ standard from ISO through their web store
http://www.iso.org/iso/store.htm
Visit the preceding link and search for the term "ISO/IEC 9075-10".
Documentation Accessibility
For information about Oracle's commitment to accessibility, visit the
Oracle Accessibility Program website at http://www.oracle.com/pls/topic/lookup?
ctx=acc&id=docacc.
xvi
Preface
Access to Oracle Support

Oracle customers that have purchased support have access to electronic support
through My Oracle Support. For information, visit http://www.oracle.com/pls/topic/
lookup?ctx=acc&id=info or visit http://www.oracle.com/pls/topic/lookup?ctx=acc&id=trs
if you are hearing impaired.
Conventions
This section describes the conventions used in the text and code examples of this
documentation set. It describes:
• Conventions in Text
• Conventions in Code Examples
Note:
Also note that command-line examples are for a UNIX environment with a
system prompt of "%". This is only by convention and can be adjusted as
appropriate for your operating system.
Conventions in Text
There are various conventions in text to help you more quickly identify special terms.
The following table describes those conventions and provides examples of their use.
Convention Meaning Example

Italics Italic typeface indicates book titles or Oracle Database Concepts
emphasis, or terms that are defined in the Ensure that the recovery catalog and target
text. database do not reside on the same disk.
UPPERCASE Uppercase monospace typeface indicates You can specify this clause only for a NUMBER
monospace elements supplied by the system. Such column.
(fixed-width) elements include parameters, privileges, You can back up the database by using the
font data types, RMAN keywords, SQL BACKUP command.
keywords, SQL*Plus or utility commands,
packages and methods, as well as system- Query the TABLE_NAME column in the
supplied column names, database objects USER_TABLES data dictionary view.
and structures, usernames, and roles. Use the DBMS_STATS.GENERATE_STATS
procedure.
xvii
Preface

lowercase Lowercase monospace typeface indicates Enter sqlplus to open SQL*Plus.
monospace executables, filenames, directory names, The password is specified in the orapwd file.
(fixed-width) and sample user-supplied elements. Such
elements include computer and database Back up the data files and control files in the /
font
names, net service names, and connect disk1/oracle/dbs directory.
identifiers, as well as user-supplied The department_id, department_name,
database objects and structures, column and location_id columns are in the
names, packages and classes, usernames hr.departments table.
and roles, program units, and parameter
Set the QUERY_REWRITE_ENABLED initialization
values.
parameter to true.
Note: Some programmatic elements use
a mixture of UPPERCASE and lowercase. Connect as oe user.
Enter these elements as shown. The JRepUtil class implements these methods.
lowercase Lowercase italic monospace font You can specify the parallel_clause.
italic represents place holders or variables. Run old_release.SQL where old_release
monospace refers to the release you installed prior to
(fixed-width) upgrading.
font
Conventions in Code Examples

Code examples illustrate SQL, PL/SQL, SQL*Plus, or other command-line statements.
They are displayed in a monospace (fixed-width) font and separated from standard
text as shown in this example:
SELECT username FROM dba_users WHERE username = 'MIGRATE';
The following table describes typographic conventions used in code examples and
provides examples of their use.
Changed first row below to note this doc uses *angle* brackets for optional.

<> In this document, angle brackets are used DECIMAL (digits < , precision >)
instead of regular brackets to enclose one
or more optional items. Do not enter the
angle brackets. (Regular brackets are not
used due to SQLJ syntax considerations.)
| A vertical bar represents a choice of two {ENABLE | DISABLE}
or more options within brackets or braces. [COMPRESS | NOCOMPRESS]
Enter one of the options. Do not enter the
vertical bar.
... Horizontal ellipsis points indicate either: CREATE TABLE ... AS subquery;SELECT
• Omission of parts of the code that are col1, col2, ... , coln FROM employees;
not directly related to the example
• That you can repeat a portion of the
code
Other notation You must enter symbols other than acctbal NUMBER(11,2);
brackets, braces, vertical bars, and ellipsis acct CONSTANT NUMBER(4) := 3;
points as shown.
xviii
Preface

Italics Italicized text indicates place holders or CONNECT SYSTEM
variables for which you must supply Enter password: password
particular values.
DB_NAME = database_name
UPPERCASE Uppercase typeface indicates elements SELECT last_name, employee_id FROM
supplied by the system. These terms are employees;
in uppercase to distinguish them from SELECT * FROM USER_TABLES;
terms you define. Unless terms appear
in brackets, enter them in the order and DROP TABLE hr.employees;
with the spelling shown. However, because
these terms are not case-sensitive, you can
enter them in lowercase.
lowercase Lowercase typeface indicates SELECT last_name, employee_id FROM
programmatic elements that you supply. employees;
For example, lowercase indicates names of sqlplus hr/hr
tables, columns, or files.
CREATE USER mjones IDENTIFIED BY
Note: Some programmatic elements use
ty3MU9;
a mixture of UPPERCASE and lowercase.
Enter these elements as shown.
xix
1
Changes in This Release for Oracle SQLJ
Developer’s Guide
Deprecated Features
The following feature is deprecated in this release, and may be desupported in a later
release:
oracle.sql.* Package
Starting Oracle Database 12c Release 2 (12.2), the oracle.sql.* package is
deprecated.
Desupported Features
The following features are no longer supported by Oracle:
Extended Datatype Support (EDS)
The Extended Datatype Support (EDS) feature is desupported in Oracle Database
19c. All Data types that the EDS feature supported are now supported natively by both
Logical Standby and Oracle GoldenGate.
The Extended Datatype Support (EDS) feature provides a mechanism for logical
standbys to support certain Oracle data types that lack native redo-based support.
For example, EDS was used to replicate tables with a SDO_GEOMETRY column.
However, starting with Oracle Database 12c Release 2 (12.2), there are no EDS-
supported Oracle data types that are not supported natively, either by Logical standby,
or by Oracle GoldenGate. This feature is desupported with Oracle Database 19c
(19.1).
SQLJ in the Server
Starting with Oracle Database 12c Release 2 (12.2), Oracle does not support server-
side SQLJ code.
Oracle supports using client-side SQLJ. However, Oracle does not support the use of
server-side SQLJ, including running stored procedures, functions, and triggers in the
database environment.
JPublisher
All Oracle JPublisher features are desupported and unavailable in Oracle Database
12c Release 2 (12.2.0.1). Oracle recommends that you use the alternatives listed
here:
• To continue to use Web service callouts, Oracle recommends that you use the
Oracle JVM Web Services Callout utility, which is a replacement for the Web
Services Callout utility.
• To replace other JPublisher automation capabilities, including mapping user-
defined SQL types or SQL types, wrapping PL/SQL packages and similar
1-1
Chapter 1
capabilities, Oracle recommends that developers use explicit steps, such as

precompiling code with SQLJ precompiler, building Java STRUCT classes, or
using other prestructured options.
See Also:
My Oracle Support Note 1937939.1 for more information about JDeveloper
deprecation and desupport:
https://support.oracle.com/CSP/main/article?
cmd=show&type=NOT&id=1937939.1
See Also:
Oracle Database Upgrade Guide to see a list of all desupported features in
this release of Oracle Database
1-2
2
Getting Started
This chapter guides you through the basics of testing your Oracle SQLJ installation
and configuration and running a simple application.
This chapter discusses the following topics:
• Assumptions and Requirements
• Checking the Installation and Configuration
• Testing the Setup
2.1 Assumptions and Requirements

This section discusses basic assumptions about your environment and requirements
of your system so that you can run SQLJ, covering the following topics:
• Assumptions About Your Environment
• Requirements for Using the Oracle SQLJ Implementation
• SQLJ Environment
• Environment Considerations
• SQLJ Backward Compatibility
2.1.1 Assumptions About Your Environment

The following assumptions are made about the system on which you will be running
the Oracle SQLJ implementation:
• You have a standard Java environment that is operational on your system. This
would typically be using a Sun Microsystems Java Development Kit (JDK), but
other implementations of Java will work. Ensure that you can run Java (typically
java) and the Java compiler (typically javac).
To translate and run SQLJ applications on a standard JDK, you must use JDK 6 or
JDK 7. You must use the JDBC driver of the same version as that of SQLJ, can be
thin or OCI8 driver
See Also:
"SQLJ Environment"
2-1
Chapter 2
Assumptions and Requirements
Note:
A Java run-time environment (JRE), such as the one installed with Oracle
Database 12c Release 2 (12.2), is not by itself sufficient for translating SQLJ
programs. However, a JRE is sufficient for running SQLJ programs that have
already been translated and compiled.
• You can already run JDBC applications in your environment.
See also:
Oracle Database JDBC Developer’s Guide
2.1.2 Requirements for Using the Oracle SQLJ Implementation

The following are required to use the Oracle SQLJ implementation:
• A database system that is accessible using your JDBC driver
• Class files for the SQLJ translator
Translator-related classes are available in the following file:
ORACLE_HOME/sqlj/lib/translator.jar
Note:
For more information about translator.jar, refer to "Set the Path and
Classpath".
• Class files for the SQLJ run time.

ORACLE_HOME/sqlj/lib/runtime12.jar
Note:
runtime12ee.jar has been deprecated since Oracle Database 11g
Release 1. Use runtime12.jar instead.
2.1.3 SQLJ Environment

To ensure that you have a fully working environment, you must consider several
aspects of your environment: SQLJ and its code generation mode, JDBC, and the
JDK.
2-2
Chapter 2
Assumptions and Requirements
Note:
Code generation is determined by the SQLJ -codegen option. Refer to "Code
Generation (-codegen)" for more information.
The following is a typical environment setup for Oracle-specific code generation:

• SQLJ code generation: -codegen=oracle (default)
• SQLJ translation library: translator.jar
• SQLJ run-time library: runtime12.jar
• JDBC drivers: Oracle Database 12c Release 2 (12.2)
• JDK version: 6 or 7
Note:
If you are running against different JDBC versions, then translate against the
earlier version.
2.1.4 Environment Considerations

You can run the application against a JDK version that is at least as high as the
version you translated the code under.
Note:
For more information about translator.jar, refer to "Set the Path and
Classpath".
2.1.5 SQLJ Backward Compatibility

You must keep in mind the following points regarding backward compatibility of the
Oracle SQLJ implementation:
• Code generated with an earlier release of the SQLJ translator can continue to
run and compile against current run-time libraries. However, this is subject to the
cross-compatibility limitations discussed in "Environment Considerations".
• Oracle-specific translator output, that is, code generated with the default -
codegen=oracle setting, must be created and executed using the runtime12.jar
library. In addition:
– Such code will be executable under future Oracle JDBC and SQLJ
implementations.
2-3
Chapter 2
Checking the Installation and Configuration
– Such code, however, will not be executable under earlier releases of Oracle
JDBC drivers and Oracle SQLJ run time. In these circumstances, you will have
to retranslate the code.
2.2 Checking the Installation and Configuration

After you have verified that the preceding assumptions and requirements are satisfied,
you must check your SQLJ installation. Note that for Oracle Database 12c Release 2
(12.2), SQLJ and its demo applications are included with this installation. You must:
• Check for Installed Directories and Files
• Set the Path and Classpath
• Verify Installation of the sqljutl Package
2.2.1 Check for Availability of SQLJ and Demo Applications

For Oracle Database 12c Release 2 (12.2), SQLJ and its demo applications are
included with the installation.
2.2.2 Check for Installed Directories and Files

Verify that the following directories have been installed and are populated:
Directories for JDBC

Refer to the Oracle Database JDBC Developer’s Guidefor information about JDBC
files that should be installed on your system.
Directories for SQLJ

Installing the Oracle Database 12c Release 2 (12.2) Java environment includes,
among other things, installing a sqlj directory under your ORACLE_HOME directory. The
sqlj directory contains the following subdirectories:
• demo (demo applications, including some referenced in this chapter)

• lib (.jar files containing class files for SQLJ)
Check whether all these directories have been created and populated, especially lib.
The ORACLE_HOME/bin directory contains utilities for all Java product areas, including
the SQLJ executable files.
2.2.3 Set the Path and Classpath

Ensure that the PATH and CLASSPATH environment variables have the necessary
settings for the Oracle SQLJ implementation. Set the PATH and CLASSPATH environment
variables as follows for the Oracle SQLJ implementation:
• Setting PATH
To run the sqlj script, which invokes the SQLJ translator, without having to fully
specify its path, verify that the PATH environment variable has been updated to
include the following:
ORACLE_HOME/bin
2-4
Chapter 2
Checking the Installation and Configuration
Use backslash (\) for Microsoft Windows. Replace ORACLE_HOME with your actual
Oracle home directory.
• Setting CLASSPATH
Update the CLASSPATH environment variable to include the current directory as well
as the following:
ORACLE_HOME/sqlj/lib/translator.jar
Use backslash (\) for Microsoft Windows. Replace ORACLE_HOME with your actual
Oracle home directory.
Include the following run-time library in the CLASSPATH:
ORACLE_HOME/sqlj/lib/runtime12.jar
In addition, you must include the following JDBC JAR files in the CLASSPATH:
ORACLE_HOME/jdbc/lib/ojdbc6.jar
ORACLE_HOME/jdbc/lib/ojdbc7.jar
Note:
– To translate or run SQLJ programs in JDK 6 environment, you

should have ojdbc6.jar in the classpath and to translate or run
SQLJ programs in JDK 7 environment, you should have ojdbc7.jar
in the classpath. Ensure that the correct JDBC JAR is picked up at
runtime for connecting to Oracle Database.
– You will not be able to run the SQLJ translator if you do not add a
run-time library. You must specify a run-time library as well as the
translator library in the CLASSPATH.
To see if SQLJ is installed correctly, and to see the version
information for SQLJ, JDBC, and Java, run the following command:
% sqlj -version-long
See Also:
"Requirements for Using the Oracle SQLJ Implementation"
2.2.4 Verify Installation of the sqljutl Package

The sqljutl package is required for online checking of stored procedures and
functions in Oracle Database instance. The package is installed automatically under
the SYS schema during installation of the server-side Java virtual machine (JVM) for
a Java-enabled database. If your database is not Java-enabled, then you will have to
manually install this package.
If you want to verify the installation of sqljutl, then issue the following SQL command
from SQL*Plus:
describe sys.sqljutl
2-5
Chapter 2
Testing the Setup
This should result in a brief description of the package.

If you get a message indicating that the package cannot be found, or if you want to
install an updated version of the package, then you can install it by using SQL*Plus to
run the sqljutl.sql script, which is located at:
ORACLE_HOME/sqlj/lib/sqljutl.sql
2.3 Testing the Setup

You can test your database, JDBC, and SQLJ setup using demo applications defined
in the following source files:
• TestInstallCreateTable.java
• TestInstallJDBC.java
• TestInstallSQLJ.sqlj
• TestInstallSQLJChecker.sqlj
There is also a Java properties file, connect.properties, that helps you set up your
database connection. You must edit this file to set appropriate user, password, and
URL values.
The demo applications discussed here are provided with your SQLJ installation in the
demo directory:
ORACLE_HOME/sqlj/demo
You may have to edit some of the source files and translate and compile them, as
appropriate. The demo applications provided with the Oracle SQLJ implementation
refer to tables on Oracle Database account with user name HR and password hr. Most
Oracle Database installations have this account. You can substitute other values for HR
and hr if desired.
Note:
Running the demo applications requires that the demo directory be the current
directory, and that the current directory (".") should be specified in the
CLASSPATH.
This section covers the following topics:

• Set Up the Run-Time Connection
• Create a Table to Verify the Database
• Verify the JDBC Driver
• Verify the SQLJ Translator and Run Time
• Verify the SQLJ Translator Connection to the Database
2-6
Chapter 2
Testing the Setup
See Also:
"Check for Availability of SQLJ and Demo Applications"
2.3.1 Set Up the Run-Time Connection

This section describes how to update the connect.properties file to configure your
Oracle connection for run time. The file is in the demo directory and looks something
like the following:
Note:
In the Oracle Database 12c Release 2 (12.2) JDBC implementation,
database URL connection strings using SIDs are deprecated. Following is
an example, where orcl is the SID:
jdbc:oracle:thin:@localhost:5221:orcl
This would now generate a warning, but not a fatal error. Instead, you
are encouraged to use database service names, such as myservice in the
following example:
jdbc:oracle:thin:@localhost:5221/myservice
# Users should uncomment one of the following URLs or add their own.
# (If using Thin, edit as appropriate.)
#sqlj.url=jdbc:oracle:thin:@localhost:5221/myservice
#sqlj.url=jdbc:oracle:oci:@
#
# User name and password here
sqlj.user=HR
sqlj.password=hr
Connecting with an Oracle JDBC Driver

Use oci in the connection string for Oracle JDBC OCI driver in any new code. For
backward compatibility, however, oci8 is still accepted. Therefore, you do not have to
change existing code.
If you are using the JDBC Thin driver, then uncomment the thin URL line in
connect.properties and edit it as appropriate for your Oracle connection. Use the
same URL that was specified when your JDBC driver was set up.
2.3.2 Create a Table to Verify the Database

The following tests assume a table called SALES. Compile and run
TestInstallCreateTable as follows:
% javac TestInstallCreateTable.java
% java TestInstallCreateTable
2-7
Chapter 2
Testing the Setup
This will create the table for you if the database and the JDBC driver are working and
the connection is set up properly in the connect.properties file.
Note:
If you already have a table called SALES in your schema and do not want
it altered, edit TestInstallCreateTable.java to change the table name.
Otherwise, your original table will be dropped and replaced.
If you do not want to use TestInstallCreateTable, then you can create the SALES
table using the following SQL statement:
CREATE TABLE SALES (
ITEM_NUMBER NUMBER,
ITEM_NAME CHAR(30),
SALES_DATE DATE,
COST NUMBER,
SALES_REP_NUMBER NUMBER,
SALES_REP_NAME CHAR(20));
2.3.3 Verify the JDBC Driver

If you want to further test Oracle JDBC driver, then use the TestInstallJDBC demo.
Verify that your connection is set up properly in connect.properties. Then, compile
and run TestInstallJDBC, as follows:
% javac TestInstallJDBC.java
% java TestInstallJDBC
The program should print:

Hello, JDBC!
2.3.4 Verify the SQLJ Translator and Run Time

Now translate and run the TestInstallSQLJ demo, a SQLJ application that has
functionality similar to that of TestInstallJDBC. Use the following command to
translate the source:
% sqlj TestInstallSQLJ.sqlj
Note that this command also compiles the application.

On a UNIX environment, the sqlj script is in ORACLE_HOME/bin, which should already
be in the PATH. On Windows, use the sqlj.exe executable in the bin directory. The
SQLJ translator.jar file has the class files for the SQLJ translator and run time. It is
located in ORACLE_HOME/sqlj/lib and should already be in the CLASSPATH.
See Also:
"Set the Path and Classpath"
2-8
Chapter 2
Testing the Setup
Now run the application as follows:

% java TestInstallSQLJ
The program should print:

Hello, SQLJ!
2.3.5 Verify the SQLJ Translator Connection to the Database

If the SQLJ translator is able to connect to a database, then it can provide online
semantics-checking of your SQL operations during translation. The SQLJ translator is
written in Java and uses JDBC to get information it needs from a database connection
that you specify. You provide the connection parameters for online semantics-checking
using the sqlj script command line or using a SQLJ properties file, which is
sqlj.properties by default.
While still in the demo directory, edit the sqlj.properties file and update, comment, or
uncomment the sqlj.password, sqlj.url, and sqlj.driver lines, as appropriate, to
reflect your database connection information. For assistance, refer to the comments in
the sqlj.properties file.
Following is an example of what the appropriate driver, URL, and password settings
might be if you are using Oracle JDBC OCI driver.
sqlj.url=jdbc:oracle:oci:@
sqlj.driver=oracle.jdbc.OracleDriver
sqlj.password=hr
Online semantics-checking is enabled as soon as you specify a user name for the
translation-time connection. You can specify the user name either by uncommenting
the sqlj.user line in the sqlj.properties file or by using the -user command-line
option. The user, password, url, and driver options all can be set either on the
command line or in the properties file.
See Also:
"Connection Options"
You can test online semantics-checking by translating the

TestInstallSQLJChecker.sqlj file located in the demo directory, as follows (or using
another user name, if appropriate):
% sqlj -user=HR TestInstallSQLJChecker.sqlj
This should produce the following error message if you are using one of Oracle JDBC
drivers:
TestInstallSQLJChecker.sqlj:41: Warning: Unable to check SQL query. Error
returned by database is: ORA-00904:
invalid column name
Edit TestInstallSQLJChecker.sqlj to fix the error on line 41. The column name
should be ITEM_NAME instead of ITEM_NAMAE. Once you make this change, you can
translate and run the application without error using the following commands:
2-9
Chapter 2
Testing the Setup
% sqlj -user=HR TestInstallSQLJChecker.sqlj

% java TestInstallSQLJChecker
If everything works, then the following line is displayed:

Hello, SQLJ Checker!
2-10
3
Introduction to SQLJ
This chapter provides a general overview of SQLJ features and scenarios. The
following topics are discussed:
• Overview of SQLJ
• Overview of SQLJ Components
• Overview of Oracle Extensions to the SQLJ Standard
• Basic Translation Steps and Run-Time Processing
• SQLJ Sample Code
• Alternative Deployment Scenarios
• Alternative Development Scenarios
3.1 Overview of SQLJ

This section introduces the basic concepts of SQLJ and discusses the complementary
relationship between Java and PL/SQL in Oracle Database applications.
SQLJ enables applications programmers to embed SQL statements in Java code
in a way that is compatible with the Java design philosophy. A SQLJ program is a
Java program containing embedded SQL statements that comply with the International
Organization for Standardization (ISO) standard SQLJ Language Reference syntax.
The Oracle SQLJ implementation supports the ISO SQLJ standard. The standard
covers only static SQL operations, which are predefined SQL operations that do not
change in real time while a user runs the application. The Oracle SQLJ implementation
also offers extensions to support dynamic SQL operations, which are not predefined
and the operations can change in real time. It is also possible to use dynamic SQL
operations through Java Database Connectivity (JDBC) code or PL/SQL code within
a SQLJ application. Typical applications contain more static SQL operations than
dynamic SQL operations.
SQLJ consists of a translator and a run-time component and is smoothly integrated
into your development environment. You can run the translator to translate, compile,
and customize the code in a single step using the sqlj front-end utility. The translation
process replaces embedded SQL statements with calls to the SQLJ run time, which
processes the SQL statements. In ISO SQLJ standard this is typically, but not
necessarily, performed through calls to a JDBC driver. To access Oracle Database,
you would typically use an Oracle JDBC driver. When you run the SQLJ application,
the run time is started to handle the SQL operations.
The SQLJ translator is conceptually similar to other Oracle precompilers and enables
you to check SQL syntax, verify SQL operations against what is available in the
schema, and check the compatibility of Java types with corresponding database types.
In this way, you can catch errors during development rather than a user catching the
errors at run time. The translator checks the following:
• Syntax of the embedded SQL statements
3-1
Chapter 3
Overview of SQLJ Components
• SQL constructs, against a specified database schema to ensure consistency

within a particular set of SQL entities (optional)
For example, it verifies table names and column names.
• Data types, to ensure that the data exchanged between Java and SQL have
compatible types and proper type conversions
The SQLJ methodology of embedding SQL statements directly in Java code is very
convenient and concise in a way that it reduces development and maintenance costs
in Java programs that require database connectivity.
Java programs can call PL/SQL stored procedures and anonymous blocks through
JDBC or SQLJ. In particular, SQLJ provides syntax for calling stored procedures
and functions from within a SQLJ statement and also supports embedded PL/SQL
anonymous blocks within a SQLJ statement.
Note:
Using PL/SQL anonymous blocks within SQLJ statements is one way to
support dynamic SQL operations in a SQLJ application. However, the Oracle
SQLJ implementation includes extensions to support dynamic SQL directly.
3.2 Overview of SQLJ Components

This section introduces the main two major SQLJ components in Oracle SQLJ
implementation. It covers the following topics:
• SQLJ Translator Functionality
• SQLJ Run Time
3.2.1 SQLJ Translator Functionality

This component is a precompiler that you run after creating SQLJ source code.
The translator, which is written in pure Java, supports a programming syntax that
enables you to embed SQL statements in SQLJ executable statements. SQLJ
executable statements and SQLJ declarations are preceded by the #sql token and
can be interspersed with Java statements in a SQLJ source code file. SQLJ source
code file names must have the .sqlj extension. The following is a sample SQLJ
statement:
#sql { INSERT INTO employees (first_name, salary) VALUES ('Joe', 43000) };
The translator produces a .java file.
You can invoke the translator using the sqlj command-line utility. On the command
line, specify the files that need to be translated and any desired SQLJ option settings.
3-2
Chapter 3
Overview of Oracle Extensions to the SQLJ Standard
See Also:
Translator Command Line and Options
3.2.2 SQLJ Run Time

This component is also written in pure Java and is invoked automatically each time
you run a SQLJ application.
Oracle JDBC calls are generated directly into the translated code and the SQLJ run
time plays a much smaller role.
See Also:
"SQLJ Run Time"
Note:
Since Oracle Database 10g Release 1, only Oracle JDBC drivers are
supported with SQLJ.
3.3 Overview of Oracle Extensions to the SQLJ Standard

The Oracle SQLJ implementation supports the ISO SQLJ standard. Using the ISO
SQLJ standard features requires a Java Development Kit (JDK) 6 or later environment
that complies with Java2 Platform, Enterprise Edition (J2EE). The SQLJ translator
accepts a broader range of SQL syntax than the ISO SQLJ standard specifies.
Note:
Oracle SQLJ implementation requires the run-time environment of JDK 6 or
JDK 7.
The ISO SQLJ standard addresses not only the SQL-92 Entry level dialect of SQL, but
also enables extension beyond that. The Oracle SQLJ implementation supports the
Oracle SQL dialect, which is a superset of SQL-92 Entry level. If you need to create
SQLJ programs that work with other databases, then avoid using SQL syntax and SQL
types that are not in the Entry level of SQL-92 and, therefore, may not be supported in
other environments.
• SQLJ Type Extensions
• SQLJ Functionality Extensions
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Chapter 3
See Also:
Type Support, and Objects_ Collections_ and OPAQUE Types for
information about SQLJ extensions provided by Oracle Database
3.3.1 SQLJ Type Extensions

The Oracle SQLJ implementation supports the following Java types as extensions to
the SQLJ standard:
• Instances of oracle.sql.* classes as wrappers for SQL data.
See Also:
"Support for JDBC 2.0 LOB Types and Oracle Type Extensions"
• Custom Java classes, object references, and collections. For example, classes
that implement the oracle.sql.ORAData interface or the JDBC standard
java.sql.SQLdata interface.
Note:
The SQLData interface is standard. Classes that implement it are
supported by JDBC drivers and databases of other vendors.
See Also:
"Custom Java Classes"
• Stream instances: BinaryStream and CharacterStream, the latter of which

replaces the deprecated AsciiStream and UnicodeStream, used as output
parameters.
See Also:
"Support for Streams"
• Iterator and result set instances as input or output parameters. The SQLJ standard
specifies them only in result expressions or cast statements.
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Chapter 3
See Also:
"Using Iterators and Result Sets as Host Variables" and "Using Iterators
and Result Sets as Stored Function Returns"
• Unicode character types: NString, NCHAR, NCLOB, and NcharCharacterStream,

the latter of which replaces the deprecated NcharAsciiStream and
NcharUnicodeStream.
See Also:
"SQLJ Extended Globalization Support"
Using any of these extensions requires Oracle-specific code generation or Oracle

customization during translation, as well as Oracle SQLJ run time and an Oracle JDBC
driver when your application runs. Do not use these or other types if you want to use
your code in other environments. To ensure that your application is portable, use the
SQLJ -warn=portable flag.
See Also:
See " Translator Command Line and Options"
3.3.2 SQLJ Functionality Extensions

The Oracle SQLJ implementation also supports the following extended functionality:
• Oracle-specific code generation
This generates JDBC code directly. Much of the SQLJ run-time functionality is
bypassed during program execution.
See Also:
"Oracle-Specific Code Generation (No Profiles)"
• Dynamic SQL in SQLJ statements
See Also:
"Support for Dynamic SQL"
• Scrollable result set iterators with additional navigation methods, and FETCH
syntax from result set iterators and scrollable result set iterators
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Basic Translation Steps and Run-Time Processing
See Also:
"Scrollable Iterators"
• Optimization flags for column and parameter size definitions
See Also:
"Column Definitions", "Parameter Size Definitions", and "Options for
Code Generation_ Optimizations_ and CHAR Comparisons"
• Flags for modified translator behavior, such as for binding host expressions by
identifier or accounting for blank padding in CHAR comparisons for WHERE clauses
• SQLJ statement caching on connection contexts
See Also:
"Statement Caching"
3.4 Basic Translation Steps and Run-Time Processing

SQLJ source code contains a mixture of standard Java source together with SQLJ
class declarations and SQLJ executable statements containing embedded SQL
statements. SQLJ source files have the .sqlj file name extension. The file name
must be a legal Java identifier. If the source file declares a public class, then the file
name must match the name of this class. If the source file does not declare a public
class, then the file name should match the name of the first defined class.
• SQLJ Translation Steps
• Summary of Translator Input and Output
• SQLJ Run-Time Processing
3.4.1 SQLJ Translation Steps

After you have written your .sqlj file, you must run SQLJ to process the files. The
following example shows SQLJ being run in its simplest form with no command-line
options for the Foo.sqlj source file with the public class Foo:
% sqlj Foo.sqlj
This command runs a front-end script or utility depending on the platform. The script
or utility reads the command line, invokes a Java virtual machine (JVM), and passes
arguments to it. The JVM invokes the SQLJ translator and acts as a front end.
3-6
Chapter 3
Figure 3-1 Flow of Control
Oracle SQLJ
emp.sqlj emp.java emp.class
SQLJ Translator Java Compiler
Checker
% sqlj emp.sqlj -user=HR/hr

DBMS % java emp
The following sequence of events occurs, presuming each step completes without
error:
1. The JVM invokes the SQLJ translator.
2. The translator parses the SQLJ and Java code in the .sqlj file, checking for
proper SQLJ syntax and looking for type mismatches between the declared SQL
data types and corresponding Java host variables. Host variables are Java local
variables that are used as input or output parameters in SQL operations.
See Also:
"Java Host_ Context_ and Result Expressions"
3. Depending on the SQLJ option settings, the translator invokes the online
semantics-checker, the offline parser, neither, or both. This is to verify syntax
of embedded SQL and PL/SQL statements and to check the use of database
elements in the code against an appropriate database schema, for online
checking. Even when neither is specified, some basic level of checking is
performed.
When online checking is specified, SQLJ will connect to a specified database
schema to verify that the database supports all the database tables, stored
procedures, and SQL syntax that the application uses. It also verifies that the
host variable types in the SQLJ application are compatible with data types of
corresponding database columns.
4. For Oracle-specific SQLJ code generation (-codegen=oracle, which is default),
SQL operations are converted directly into Oracle JDBC calls.
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See Also:
Generated Java code is put into a .java output file containing the following:
• Any class definitions and Java code from the .sqlj source file
• Class definitions created as a result of the SQLJ iterator and connection
context declarations
See Also:
"Overview of SQLJ Declarations"
• Calls to Oracle JDBC drivers to implement the actions of the embedded SQL
operations
5. The JVM invokes the Java compiler, which is usually, but not necessarily, the
standard javac provided with the Sun Microsystems JDK.
6. The compiler compiles the Java source file generated in Step 4 and produces
Java .class files as appropriate. This will include a .class file for each class that
is defined, each of the SQLJ declarations.
See Also:
"Internal Translator Operations"
General SQLJ Notes

Consider the following when translating and running SQLJ applications:
• The preceding is a very generic example. It is also possible to specify
existing .java files on the command line to be compiled and to be available for
type resolution as well.
See Also:
"Translator Command Line and Properties Files"
• Your application requires an Oracle JDBC driver when it runs, even if your code
does not use Oracle-specific features.
3.4.2 Summary of Translator Input and Output

This section summarizes what the SQLJ translator takes as input, what it produces as
output, and where it places its output. This section covers the following topics:
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Chapter 3
• Translator Input
• Translator Output
• Output File Locations
Note:
This discussion mentions iterator class and connection context class
declarations. Iterators are similar to JDBC result sets and connection
contexts are used for database connections.
3.4.2.1 Translator Input

The SQLJ translator takes one or more .sqlj source files as input, which can be
specified on the command line. The name of the main .sqlj file is based on the public
class it defines, if any, else on the first class it defines.
If the main .sqlj file defines the MyClass class, then the source file name must be:
MyClass.sqlj
This must also be the file name if there are no public class definitions, but MyClass is
the first class defined. You must define each public class in separate.sqlj files. When
you run SQLJ, you can also specify numerous SQLJ options on the command line or
in the properties files.
See Also:
3.4.2.2 Translator Output

The translation step produces a Java source file for each .sqlj file in the application,
presuming the source code uses SQLJ executable statements.
SQLJ generates Java source files as follows:
• Java source files are .java files with the same base names as the .sqlj files.
For example, the translator produces MyClass.java corresponding to
MyClass.sqlj, which defines the MyClass class. The output .java file also
contains class definitions for any iterators or connection context classes declared
in the .sqlj file.
The compilation step compiles the Java source file into multiple class files. One .class
file is generated for each class defined in the .sqlj source file. Additional .class
files are produced if you declared any SQLJ iterators or connection contexts. Also,
separate .class files will be produced for any inner classes or anonymous classes in
the code.
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See Also:
The .class files are named as follows:
• The class file for each class defined consists of the name of the class with
the .class extension. For example, the translator output file MyClass.java is
compiled into the MyClass.class class file.
• The translator names iterator classes and connection context classes according to
how you declare them. For example, if you declare an iterator MyIter, then the
compiler will generate a corresponding MyIter.class class file.
3.4.2.3 Output File Locations

By default, SQLJ places the generated .java files in the same directory as the .sqlj
file. You can specify a different .java file location using the SQLJ -dir option.
By default, SQLJ places the generated .class and .ser files in the same directory
as the generated .java files. You can specify a different location for .class and .ser
files using the SQLJ -d option. This option setting is passed to the Java compiler so
that .class files and .ser files will be in the same location.
For both the -d and -dir option, you must specify a directory that already exists.
See Also:
"Options for Output Files and Directories"
3.4.3 SQLJ Run-Time Processing

This section discusses run-time processing during program execution.
When you translate with the default -codegen=oracle setting, your program performs
the following at run time:
• Executes Oracle-specific application programming interfaces (APIs) that ensure
batching support and proper creation and closing of Oracle JDBC statements
• Directly calls Oracle JDBC APIs for registering, passing, and retrieving parameters
and result sets
See Also:
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Chapter 3
SQLJ Sample Code
3.5 SQLJ Sample Code

This section presents a side-by-side comparison of two versions of the same sample
code, where one version is written in SQLJ and the other in JDBC. The objective of
this section is to point out the differences in coding requirements between SQLJ and
JDBC. This section covers:
• SQLJ Version of the Sample Code
• JDBC Version of the Sample Code
Note:
The particulars of SQLJ statements and features used here are described
later in this manual, but this example is still useful here to give you a general
idea in comparing and contrasting SQLJ and JDBC. You can look at it again
when you are more familiar with SQLJ concepts and features.
In the sample, two methods are defined: getEmployeeAddress(), which selects and
returns an employee's address from a table based on the employee's number, and
updateAddress(), which takes the retrieved address, calls a stored procedure, and
returns the updated address to the database.
In both versions of the sample code, the following assumptions are made:
• A SQL script has been run to create the schema in the database and populate the
tables. Both versions of the sample code refer to objects and tables created by this
script.
• The UPDATE_ADDRESS() PL/SQL stored function exists, and it updates a given
address.
• The Connection object (for JDBC) and default connection context (for SQLJ) have
been created previously by the caller.
• Exceptions are handled by the caller.
• The value of the address argument, addr, passed to the updateAddress() method
can be null.
Note:
The JDBC and SQLJ versions of the sample code are only partial
samples and cannot run independently. There is no main() method in
either.
3.5.1 SQLJ Version of the Sample Code

The SQLJ version of the sample code that defines methods to retrieve an employee's
address from the database, update the address, and return it to the database is as
follows:
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SQLJ Sample Code
import java.sql.*;
/**
This is what you have to do in SQLJ
**/
public class SimpleDemoSQLJ // line 6
{
//TO DO: make a main that calls this
public Address getEmployeeAddress(int empno) // line 10

throws SQLException
{
Address addr; // line 13
#sql { SELECT office_addr INTO :addr FROM employees
WHERE empnumber = :empno };
return addr;
}
// line 18
public Address updateAddress(Address addr)
throws SQLException
{
#sql addr = { VALUES(UPDATE_ADDRESS(:addr)) }; // line 22
return addr;
}
}
Line 10
The getEmployeeAddress() method does not require an explicit Connection object.
SQLJ can use a default connection context instance, which should be initialized
somewhere earlier in the application.
Lines 13-15
The getEmployeeAddress() method retrieves an employee address according to the
employee number. Use standard SQLJ SELECT INTO syntax to select an employee's
address from the employee table if the employee number matches the one (empno)
passed in to getEmployeeAddress(). This requires a declaration of the Address object
(addr) that will receive the data. The empno and addr variables are used as input host
variables.
Line 16
The getEmployeeAddress() method returns the addr object.
Line 19
The updateAddress() method also uses the default connection context instance.
Lines 19-22
The address is passed to the updateAddress() method, which passes it to the
database. The database updates the address and passes it back. The actual
updating of the address is performed by the UPDATE_ADDRESS() stored function. Use
standard SQLJ function-call syntax to receive the addr address object returned by
UPDATE_ADDRESS().
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SQLJ Sample Code
Line 23
The updateAddress() method returns the addr object.
Specific Features of the SQLJ Version of the Code

Note the following features of the SQLJ version of the sample code:
• An explicit connection is not required. SQLJ can use a default connection context
that has been initialized previously in the application.
• No data type casting is required.
• SQLJ does not require knowledge of _SQL_TYPECODE, _SQL_NAME, or factories.
• NULL value data is processed implicitly.
• No explicit code for resource management (for example, closing statements or
results sets) is required.
• SQLJ embeds host variables, in contrast to JDBC, which uses parameter markers.
• String concatenation for long SQL statements is not required.
• You do not have to register output parameters.
• SQLJ syntax is simpler. For example, SELECT INTO statements are supported and
ODBC-style escapes are not used.
• You do not have to implement your own statement cache. By default, SQLJ will
automatically cache #sql statements. This results in improved performance, for
example, if you repeatedly call getEmployeeAddress() and updateAddress().
3.5.2 JDBC Version of the Sample Code

If you are familiar with JDBC, then you can check the following the JDBC version of
the sample code, which defines methods to retrieve an employee's address from the
database, update the address, and return it to the database.
Note:
The TO DO items in the comment lines indicate where you might want to add
additional code to increase the usefulness of the code sample.
import java.sql.*;
import oracle.jdbc.*;
/**
This is what you have to do in JDBC
**/
public class SimpleDemoJDBC // line 7
{
//TO DO: make a main that calls this
public Address getEmployeeAddress(int empno, Connection conn)

throws SQLException // line 13
{
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Alternative Deployment Scenarios
Address addr;
PreparedStatement pstmt = // line 16
conn.prepareStatement("SELECT office_addr FROM employees" +
" WHERE empnumber = ?");
pstmt.setInt(1, empno);
OracleResultSet rs = (OracleResultSet)pstmt.executeQuery();
rs.next(); // line 21
//TO DO: what if false (result set contains no data)?
addr = (Address)rs.getORAData(1, Address.getORADataFactory());
//TO DO: what if additional rows?
rs.close(); // line 25
pstmt.close();
return addr; // line
27
}
public Address updateAddress(Address addr, Connection conn)
throws SQLException // line 30
{
OracleCallableStatement cstmt = (OracleCallableStatement)
conn.prepareCall("{ ? = call UPDATE_ADDRESS(?) }"); //line 34
cstmt.registerOutParameter(1, Address._SQL_TYPECODE, Address._SQL_NAME);
// line 36
if (addr == null) {
cstmt.setNull(2, Address._SQL_TYPECODE, Address._SQL_NAME);
} else {
cstmt.setORAData(2, addr);
}
cstmt.executeUpdate(); // line 43
addr = (Address)cstmt.getORAData(1, Address.getORADataFactory());
cstmt.close(); // line 45
return addr;
}
}
3.6 Alternative Deployment Scenarios

Although this manual mainly discusses writing for client-side SQLJ applications, you
may find it useful to run SQLJ code from an applet.
3.6.1 Running SQLJ in Applets

Because the SQLJ run time is pure Java, you can use SQLJ source code in applets as
well as applications. However, there are a few considerations.
See Also:

• General Development and Deployment Considerations
• General End User Considerations
• Java Environment and the Java Plug-In
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Alternative Deployment Scenarios
3.6.1.1 General Development and Deployment Considerations

The following general considerations apply to the use of SQLJ in applets:
• You must package all the SQLJ run-time packages with your applet. The packages
are:
sqlj.runtime
sqlj.runtime.ref
sqlj.runtime.error
Also package the following if you used Oracle customization:

oracle.sqlj.runtime
oracle.sqlj.runtime.error
These packages are included with your Oracle installation in one of several run-
time libraries in the ORACLE_HOME/lib directory.
See Also:
• You must specify a pure Java JDBC driver, such as Oracle JDBC Thin driver, for
your database connection.
• You must explicitly specify a connection context instance for each SQLJ
executable statement in an applet. This is a requirement because you could
conceivably run two SQLJ applets in a single browser and, thus, in the same
JVM.
See Also:
"Connection Considerations"
• The default translator setting -codegen=oracle generates Oracle-specific code.

This will eliminate the use of Java reflection at run time and, thus, increase
portability across different browser environments.
3.6.1.2 General End User Considerations

When end users run your SQLJ applet, classes in their CLASSPATH may conflict with
classes that are downloaded with the applet. Therefore, Oracle recommends that end
users clear their CLASSPATH before running the applet.
3.6.1.3 Java Environment and the Java Plug-In

The following are some additional considerations regarding the Java environment and
use of Oracle-specific features:
• SQLJ requires the run-time environment of JDK 6 or JDK 7. Users cannot run
SQLJ applets in browsers using earlier JDK versions, without a plug-in. One option
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Alternative Development Scenarios
is to use a Java plug-in offered by Sun Microsystems. For information, refer to the
following:
http://www.oracle.com/technetwork/java/index.html
• Applets using Oracle-specific features require Oracle SQLJ run time to work.
Oracle SQLJ run time consists of the classes in the SQLJ run-time library
file under oracle.sqlj.*. Oracle SQLJ runtime.jar library requires the Java
Reflection API, java.lang.reflect.*. Most browsers do not support the
Reflection API or impose security restrictions, but the Sun Microsystems Java
plug-in provides support for the Reflection API.
Note:
The term "Oracle-specific features" refers to the use of Oracle type
extensions (discussed in Type Support) and the use of SQLJ features
that require Oracle-specific code generation or, for ISO SQLJ standard
code generation, require your application to be customized to work
against Oracle Database instance. (For example, this is true of the SET
statement, discussed in Basic Language Features.)
The preceding issues can be summarized as follows, focusing on users with Internet
Explorer and Netscape browsers:
• The SQLJ and JDBC versions should match. For example, to use the SQLJ 9.0.0
run time, you must have an Oracle 9.0.0 or earlier JDBC driver.
See Also:
• If you use object types, JDBC 2.0 types, REF CURSORs, or the CAST statement in
your SQLJ statements, then you must adhere to your choice of the following:
– Use the default -codegen=oracle setting when you translate your applet.
– Ensure that the browser that you use supports JDK 6 and permits reflection.
– Run your applet through a browser Java plug-in.
3.7 Alternative Development Scenarios

The discussion in this book assumes that you are coding manually on a UNIX
environment for English-language deployment. However, you can use SQLJ on
other platforms and with integrated development environments (IDEs). There is also
globalization support for deployment to other languages. This section covers the
following topics:
• SQLJ Globalization Support
• SQLJ in Oracle JDeveloper 10g and Other IDEs
• Windows Considerations
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Chapter 3
3.7.1 SQLJ Globalization Support

Support for native languages and character encodings by the Oracle SQLJ
implementation is based on Java built-in globalization support capabilities.
The standard user.language and file.encoding properties of the JVM determine
appropriate language and encoding for translator and run-time messages. The SQLJ
-encoding option determines encoding for interpreting and generating source files
during translation.
See Also:
"Globalization Support in the Translator and Run Time"
3.7.2 SQLJ in Oracle JDeveloper 10g and Other IDEs

The Oracle SQLJ implementation includes a programmatic API so that it can be
embedded in IDEs, such as Oracle JDeveloper 10g. The IDE takes on a role similar to
that of the front-end sqlj script, invoking the translator, semantics-checker, compiler,
and customizer (as applicable).
JDeveloper is a Jave-based, cross-platform visual development environment for Java
programming. The JDeveloper Suite enables developers to build multitier, scalable
Internet applications using Java across the Oracle Internet Platform. The core product
of the suite, the JDeveloper IDE, excels in creating, debugging, and deploying
component-based applications.
Oracle JDBC OCI and Thin drivers are included with JDeveloper. The compilation
functionality of JDeveloper includes an integrated SQLJ translator so that your SQLJ
application is translated automatically as it is compiled.
3.7.3 Windows Considerations

Note the following if you are using a Microsoft Windows environment instead of a
UNIX environment:
• This manual uses UNIX syntax. Use platform-specific file names and directory
separators, such as "\" on Microsoft Windows, that are appropriate for your
platform, because your JVM expects file names and paths in the platform-specific
format. This is true even if you are using a shell, such as ksh, that permits a
different file name syntax.
• For UNIX, the Oracle SQLJ implementation provides a front-end script, sqlj, that
you use to invoke the SQLJ translator. On Microsoft Windows, Oracle instead
provides an executable file, sqlj.exe. Using a script is not feasible on Microsoft
Windows because .bat files on these platforms do not support embedded equals
signs (=) in arguments, string operations on arguments, or wildcard characters in
file name arguments.
• How to set environment variables is specific to the operating system. There may
also be OS-specific restrictions. In Windows 95, use the Environment tab in the
System control panel. Additionally, because Windows 95 does not support the "="
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character in variable settings, SQLJ supports the use of "#" instead of "=" in setting
SQLJ_OPTIONS, an environment variable that SQLJ can use for option settings.
Consult your operating system documentation regarding settings and syntax for
environment variables, and be aware of any size limitations.
• As with any operating system and environment you use, be aware of specific
limitations. In particular, the complete, expanded SQLJ command line must
not exceed the maximum command-line size, which is 250 characters for
Windows 95 and 4000 characters for Windows NT. Consult your operating system
documentation.
Refer to the release notes for Windows for additional information.
3-18
4
Key Programming Considerations
This chapter discusses key issues to consider before developing and running your
SQLJ application, and also provides a summary and sample applications. The
following topics are discussed:
• Selection of the JDBC Driver
• Connection Considerations
• NULL-Handling
• Exception-Handling Basics
• Basic Transaction Control
• Summary: First Steps in SQLJ Code
• Oracle-Specific Code Generation (No Profiles)
• ISO Standard Code Generation
• Requirements and Restrictions for Naming
• Considerations for SQLJ in the Middle Tier
4.1 Selection of the JDBC Driver

You must consider which Java Database Connectivity (JDBC) driver will be
appropriate for your situation and whether it may be advantageous to use different
drivers for translation and run time. You must choose or register the appropriate driver
class for each and then specify the driver in your connection URL.
Note:
Your application will require an Oracle JDBC driver if you use Oracle-specific
code generation or if you use ISO SQLJ standard code generation with
Oracle customizer, even if your code does not actually use Oracle-specific
features.

• Overview of Oracle JDBC Drivers
• Driver Selection for Translation
• Driver Selection and Registration for Run Time
4.1.1 Overview of Oracle JDBC Drivers

Oracle provides the following JDBC drivers:
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Chapter 4
Selection of the JDBC Driver
• Oracle Call Interface (OCI) driver: For client-side use with an Oracle client
installation.
• Thin driver: A pure Java driver for client-side use, particularly with applets. It does
not require an Oracle client installation.
• Server-side Thin driver: Is functionally the same as the client-side Thin driver, but
is for code that runs inside Oracle Database instance and needs to access a
remote server.
• Server-side internal driver: For code that runs inside the target server, that is,
inside Oracle Database instance that it must access.
Oracle Database 12c Release 1 (12.1) provides client-side drivers compatible with
JDK 6 and JDK 7.
See Also:
Oracle Database JDBC Developer's Guide
Note:
Remember that your choices may differ between translation time and run
time. For example, you may want to use Oracle JDBC OCI driver at
translation time for semantics-checking, but Oracle JDBC Thin driver at run
time.
Core JDBC Functionality

The core functionality of all Oracle JDBC drivers is the same. They support the same
feature set, syntax, programming interfaces, and Oracle extensions.
All Oracle JDBC drivers are supported by the oracle.jdbc.OracleDriver class.
JDBC OCI Driver

Oracle JDBC OCI driver accesses the database by calling the OCI directly from Java,
providing the highest compatibility with the different Oracle Database versions. These
drivers support installed Oracle Net adapters, including interprocess communication
(IPC), named pipes, TCP/IP, and IPX/SPX.
The use of native methods to call C entry points makes the OCI driver dependent on
the Oracle platform, requiring an Oracle client installation that includes Oracle Net.
Therefore it is not suitable for applets.
Connection strings for the OCI driver are of the following form, where tns is an
optional TNS alias or full TNS specification:
jdbc:oracle:oci:@<tns>
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Chapter 4
Note:
For backward compatibility, oci8 is still acceptable instead of oci.
JDBC Thin Driver

Oracle JDBC Thin driver is a platform-independent, pure Java implementation that
uses Java sockets to connect directly to Oracle Database from any Oracle or non-
Oracle client. It can be downloaded into a browser simultaneously with the Java applet
being run.
The JDBC Thin driver supports only TCP/IP protocol and requires a TNS listener to
be listening on TCP/IP sockets from the database server. When the JDBC Thin driver
is used with an applet, the client browser must have the capability to support Java
sockets.
Connection strings for the JDBC Thin driver are typically of the following form:
jdbc:oracle:thin:@host:port/servicename
See Also:
Oracle Database JDBC Developer's Guide for information about database
service names
In Oracle Database 12c Release 2 (12.2), connection strings using SIDs are
deprecated, but are still supported for backward compatibility:
jdbc:oracle:thin:@host:port:sid
JDBC Server-Side Thin Driver

Oracle JDBC server-side Thin driver offers the same functionality as the client-side
JDBC Thin driver, but runs inside the database and accesses a remote server. This is
useful in accessing one Oracle Database instance from inside another, such as from a
Java stored procedure.
Connection strings for the server-side Thin driver are the same as for the client-side
Thin driver.
Note:
In order to leave the originating database when using the server-side Thin
driver, the user account must have SocketPermission assigned. Refer to
the Oracle Database JDBC Developer's Guide for more information. Also,
refer to the Oracle Database Java Developer's Guide for general information
about SocketPermission and other permissions.
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Chapter 4
JDBC Server-Side Internal Driver

Oracle JDBC server-side internal driver provides support for any Java code that runs
inside the target Oracle Database instance where the SQL operations are to be
performed. The server-side internal driver enables Oracle Java virtual machine (JVM)
to communicate directly with the SQL engine. This driver is the default JDBC driver
for SQLJ code running as a stored procedure, stored function, or trigger in Oracle
Database 12c Release 2 (12.2).
Connection strings for the server-side internal driver are of the following form:
jdbc:oracle:kprb:
If your SQLJ code uses the default connection context, then SQLJ automatically uses
this driver for code running in Oracle JVM.
4.1.2 Driver Selection for Translation

Use SQLJ option settings, either on the command line or in a properties file, to choose
the driver manager class and specify a driver for translation.
Use the SQLJ -driver option to choose any driver manager class other than
OracleDriver, which is the default.
Specify the particular JDBC driver to choose, such as JDBC Thin or JDBC OCI for
Oracle Database, as part of the connection URL you specify in the SQLJ -url option.
See Also:
You will typically, but not necessarily, use the same driver that you use in your source
code for the run-time connection.
Note:
Remember that the -driver option does not choose a particular driver. It
registers a driver class with the driver manager. One driver class might be
used for multiple driver protocols, such as OracleDriver, which is used for
all of Oracle JDBC protocols.
4.1.3 Driver Selection and Registration for Run Time

To connect to the database at run time, you must register one or more drivers that will
understand the URLs you specify for any of your connection instances, whether they
are instances of the sqlj.runtime.ref.DefaultContext class or of any connection
context classes that you declare.
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Connection Considerations
If you are using an Oracle JDBC driver and create a default connection
using the Oracle.connect() method, then SQLJ handles this automatically. The
Oracle.connect() method registers the oracle.jdbc.OracleDriver class.
If you are using an Oracle JDBC driver, but do not use Oracle.connect(), then you
must manually register the OracleDriver class, as follows:
DriverManager.registerDriver(new oracle.jdbc.OracleDriver());
If you are not using an Oracle JDBC driver, then you must register some appropriate
driver class, as follows:
DriverManager.registerDriver(new mydriver.jdbc.driver.MyDriver());
In any case, you must also set your connection URL, user name, and password.
See Also:
"Single Connection or Multiple Connections Using DefaultContext"
Note:
As an alternative to using the JDBC driver manager in establishing
JDBC connections, you can use data sources. You can specify a data
source in a with clause, as described in "Declaration WITH Clause". For
general information about data sources, refer to the Oracle Database JDBC
Developer's Guide.
4.2 Connection Considerations

When deciding what database connection or connections you will need for your SQLJ
application, consider the following:
• Will you need just one database connection or multiple connections?
• If using multiple connections (possibly to multiple schemas), then will each
connection use SQL entities of the same name: tables of the same name, columns
of the same name and data types, stored procedures of the same name and
signature, and so on?
• Will you need different connections for translation and run time or will the same
suffice for both?
A SQLJ executable statement can specify a particular connection context instance,
either of DefaultContext or of a declared connection context class, for its database
connection. Alternatively, it can omit the connection context specification and use the
default connection, which is an instance of DefaultContext that was previously set as
the default.
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Note:
If your operations will use different sets of SQL entities, then you will typically
want to declare and use additional connection context classes.

• Single Connection or Multiple Connections Using DefaultContext
• Closing Connections
• Multiple Connections Using Declared Connection Context Classes
• More About the Oracle Class
• More About the DefaultContext Class
• Connection for Translation
• Connection for Customization
4.2.1 Single Connection or Multiple Connections Using DefaultContext

This section discusses scenarios where you will use connection instances of only the
DefaultContext class.
This is typical if you are using a single connection, or multiple connections that use
SQL entities with the same names and data types.
Single Connection
For a single connection, use one instance of the DefaultContext class specifying the
database URL, user name, and password, when you construct your DefaultContext
object.
You can use the connect() method of the oracle.sqlj.runtime.Oracle class to
accomplish this. Calling this method automatically initializes the default connection
context instance. This method has several signatures, including ones that allow you to
specify user name, password, and URL, either directly or using a properties file. In the
following example, the properties file connect.properties is used:
Oracle.connect(MyClass.class, "connect.properties");
Note:
The connect.properties file is searched for relative to the specified class. In
the example, if MyClass is located in my-package, then connect.properties
must be found in the same package location, my-package.
If you use connect.properties, then you must edit it appropriately and

package it with your application. In this example, you must also import the
oracle.sqlj.runtime.Oracle class.
Alternatively, you can specify user name, password, and URL directly:
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Oracle.connect("jdbc:oracle:thin:@localhost:5221/myservice", "HR", "hr");
In this example, the connection will use the JDBC Thin driver to connect the HR user
with the password, hr, to a database on the computer, localhost, through port 5221,
where myservice is the name of the database service for the connection.
Either of these examples creates a special static instance of the DefaultContext class
and installs it as your default connection. It is not necessary to do anything with this
DefaultContext instance directly.
Once you have completed these steps, you do not need to specify the connection for
any of the SQLJ executable statements in your application, if you want them all to use
the default connection.
Note that in using a JDBC Thin driver, the URL must include the host name, port
number, and service name (or SID, which is deprecated in Oracle Database 12c
Release 2 (12.2)), as in the preceding example. Also, the database must have a
listener running at the specified port. In using the JDBC OCI driver, no service name
(or SID) is required if you intend to use the default account of the client, as will be the
case in examples in this document. Alternatively, you can use name-value pairs.
See Also:
Oracle Database JDBC Developer's Guide for more information
The following URL will connect to the default account of the client:
jdbc:oracle:oci:@
Note:
• Oracle.connect() will not set your default connection if one had already
been set. In that case, it returns null. This enables you to use the
same code on a client or in the server. If you do want to override your
default connection, then use the static setDefaultContext() method of
DefaultContext.
• The Oracle.connect() method defaults to a false setting of the auto-
commit flag. However, it also has signatures to set it explicitly. In the
Oracle JDBC implementation, the auto-commit flag defaults to true.
• You can optionally specify getClass() instead of MyClass.class in the
Oracle.connect() call, as long as you are not calling getClass() from
a static method. The getClass() method is used in some of the SQLJ
demo applications.
• You can access the static DefaultContext instance, which corresponds
to your default connection, as follows:
DefaultContext.getDefaultContext();
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Multiple Connections
For multiple connections, you can create and use additional instances of the
DefaultContext class, while optionally still using the default connection.
You can use the Oracle.getConnection() method to instantiate DefaultContext, as

in the following examples.
First, consider a case where you want most statements to use the default connection,
but other statements to use a different connection. You must create one additional
instance of DefaultContext:
DefaultContext ctx = Oracle.getConnection (
"jdbc:oracle:thin:@localhost2:5221/myservice2", "bill", "lion");
Note:
ctx could also use the HR/hr schema, if you want to perform multiple sets of
operations on the same schema.
When you want to use the default connection, it is not necessary to specify a
connection context:
#sql { SQL operation };
This is actually a shortcut for the following:

#sql [DefaultContext.getDefaultContext()] { SQL operation };
When you want to use the additional connection, specify ctx as the connection:
#sql [ctx] { SQL operation };
Next, consider situations where you want to use multiple connections, where each
of them is a named DefaultContext instance. This enables you to switch your
connection back and forth.
The following statements establish multiple connections to the same schema (in case
you want to use multiple Oracle Database sessions or transactions, for example).
Instantiate the DefaultContext class for each connection you will need:
DefaultContext ctx1 = Oracle.getConnection
("jdbc:oracle:thin:@localhost1:5221/myservice1", "HR", "hr");
This creates two connection context instances that would use the same schema,
connecting to HR/hr using service myservice1 on the computer localhost1, using
Oracle JDBC Thin driver.
Now, consider a case where you would want multiple connections to different
schemas. Again, instantiate the DefaultContext class for each connection you will
need:
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("jdbc:oracle:thin:@localhost2:5221/myservice2", "bill", "lion");
This creates two connection context instances that use Oracle JDBC Thin driver but
use different schemas. The ctx1 object connects to HR/hr using service myservice1
on the computer localhost1, while the ctx2 object connects to bill/lion using
service myservice2 on the computer localhost2.
There are two ways to switch back and forth between these connections for the SQLJ
executable statements in your application:
• If you switch back and forth frequently, then you can specify the connection for
each statement in your application:
#sql [ctx1] { SQL operation };
...
#sql [ctx2] { SQL operation };
Note:
Include the square brackets around the connection context instance
name; they are part of the syntax.
• If you use either of the connections several times in a row within your code
flow, then you can periodically use the static setDefaultContext() method of
the DefaultContext class to reset the default connection. This method initializes
the default connection context instance. This way, you can avoid specifying
connections in your SQLJ statements.
DefaultContext.setDefaultContext(ctx1);
#sql { SQL operation }; // These three statements all use ctx1
...
DefaultContext.setDefaultContext(ctx2);
#sql { SQL operation }; // These three statements all use ctx2
Note:
Because the preceding statements do not specify connection contexts,
at translation time they will all be checked against the default connection
context.
4.2.2 Closing Connections

It is advisable to close your connection context instances when you are done,
preferably in a finally clause of a try block (in case your application terminates
with an exception).
The DefaultContext class, as well as any connection context classes that you
declare, includes a close() method. Calling this method closes the SQLJ connection
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context instance and, by default, also closes the underlying JDBC connection instance
and the physical connection.
In addition, the oracle.sqlj.runtime.Oracle class has a static close() method to
close the default connection only. In the following example, presume ctx is an instance
of any connection context class:
...
finally
{
ctx.close();
}
...
Alternatively, if the finally clause is not within a try block in case a SQL exception is
encountered:
...
finally
{
try { ctx.close(); } catch(SQLException ex) {...}
}
...
Or, to close the default connection, the Oracle class also provides a close() method:
...
finally
{
Oracle.close();
}
...
Always commit or roll back any pending changes before closing the connection.
Whether there would be an implicit COMMIT operation as the connection is closed is
not specified in the JDBC standard and may vary from vendor to vendor. For Oracle,
there is an implicit COMMIT when a connection is closed, and an implicit ROLLBACK when
a connection is garbage-collected without being closed, but it is not advisable to rely
on these mechanisms.
Note:
It is also possible to close a connection context instance without closing the
underlying connection (in case the underlying connection is shared).
4.2.3 Multiple Connections Using Declared Connection Context

Classes
For multiple connections that use different sets of SQL entities, it is advantageous to
use connection context declarations to define additional connection context classes.
Having a separate connection context class for each set of SQL entities that you use
enables SQLJ to do more rigorous semantics-checking of your code.
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See Also:
"Connection Contexts"
4.2.4 More About the Oracle Class

The Oracle SQLJ implementation provides the oracle.sqlj.runtime.Oracle class to
simplify the process of creating and using instances of the DefaultContext class.
The static connect() method initializes the default connection context instance,
instantiating a DefaultContext object and installing it as your default connection. You
do not need to assign or use the DefaultContext instance returned by connect(). If
you had already established a default connection, then connect() returns null.
The static getConnection() method simply instantiates a DefaultContext object and

returns it. You can use the returned instance as desired.
Both methods register Oracle JDBC driver manager automatically if the
oracle.jdbc.OracleDriver class is found in the CLASSPATH. The static close()
method closes the default connection.
Signatures of the Oracle.connect() and Oracle.getConnection() Methods

Both the method have signatures that take the following parameter sets as input:
• URL (String), user name (String), password (String)
• URL (String), user name (String), password (String), auto-commit flag
(boolean)
• URL (String), java.util.Properties object containing properties for the
connection
• URL (String), java.util.Properties object, auto-commit flag (boolean)
• URL (String) fully specifying the connection, including user name and password
The following is an example of the format of a URL string specifying user name
(HR) and password (hr) when using Oracle JDBC drivers, in this case the JDBC
Thin driver:
"jdbc:oracle:thin:HR/hr@localhost:5221/myservice"
• URL (String), auto-commit flag (boolean)
• A java.lang.Class object for the class relative to which the properties file is
loaded, name of properties file (String)
• A java.lang.Class object, name of properties file (String), auto-commit flag
(boolean)
• A java.lang.Class object, name of properties file (String), user name (String),
password (String)
• A java.lang.Class object, name of properties file (String), user name (String),
password (String), auto-commit flag (boolean)
• JDBC connection object (Connection)
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• SQLJ connection context object

These last two signatures inherit an existing database connection. When you inherit a
connection, you will also inherit the auto-commit setting of that connection.
The auto-commit flag specifies whether SQL operations are automatically committed.
For the Oracle.connect() and Oracle.getConnection() methods only, the default
is false. If that is the setting you want, then you can use one of the signatures
that does not take auto-commit as input. However, anytime you use a constructor to
create an instance of a connection context class, including DefaultContext, you must
specify the auto-commit setting. In the Oracle JDBC implementation, the default for the
auto-commit flag is true.
See Also:
"Basic Transaction Control" and "Single Connection or Multiple Connections
Using DefaultContext"
Optional Oracle.close() Method Parameters

In using the Oracle.close() method to close the default connection, you have
the option of specifying whether or not to close the underlying physical database
connection. By default it is closed. This is relevant if you are sharing this physical
connection between multiple connection objects, either SQLJ connection context
instances or JDBC connection instances.
You can keep the underlying physical connection open as follows:
Oracle.close(ConnectionContext.KEEP_CONNECTION);
You can close the underlying physical connection (default behavior) as follows:
Oracle.close(ConnectionContext.CLOSE_CONNECTION);
KEEP_CONNECTION and CLOSE_CONNECTION are static constants of the

ConnectionContext interface.
See Also:
"Closing Shared Connections"
4.2.5 More About the DefaultContext Class

The sqlj.runtime.ref.DefaultContext class provides a complete default
implementation of a connection context class. As with classes created using
a connection context declaration, the DefaultContext class implements the
sqlj.runtime.ConnectionContext interface. The DefaultContext class has the same
class definition that would have been generated by the SQLJ translator from the
declaration:
#sql public context DefaultContext;
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DefaultContext Methods
The following are the key methods of the DefaultContext class:
• getConnection()
Gets the underlying JDBC connection object. This is useful if you want to have
JDBC code in your application, which is one way to use dynamic SQL operations.
You can also use the setAutoCommit() method of the underlying JDBC connection
object to set the auto-commit flag for the connection.
• setDefaultContext()
Sets the default connection your application uses. This is a static method and
takes a DefaultContext instance as input. SQLJ executable statements that do
not specify a connection context instance will use the default connection that you
define using this method or the Oracle.connect() method.
• getDefaultContext()
Returns the DefaultContext instance currently defined as the default connection
for your application. This is a static method.
• close()
Closes the connection context instance.
The getConnection() and close() methods are specified in the
sqlj.runtime.ConnectionContext interface.
Note:
On a client, getDefaultContext() returns null if setDefaultContext() was
not previously called. However, if a data source object has been bound under
"jdbc/defaultDataSource" in JNDI, then the client will use this data source
object as its default connection.
In the server, getDefaultContext() returns the default connection, which is
the connection to the server itself.
DefaultContext Constructors
It is typical to instantiate DefaultContext using the Oracle.connect() or
Oracle.getConnection() method. However, if you want to create an instance directly,
then there are five constructors for DefaultContext. The different input parameter sets
for these constructors are:
• URL (String), user name (String), password (String), auto-commit (boolean)
• URL (String), java.util.Properties object, auto-commit (boolean)
• URL (String fully specifying connection and including user name and password),
auto-commit setting (boolean)
The following is an example of the format of a URL specifying user name and
password when using Oracle JDBC drivers, in this case the JDBC Thin driver:
"jdbc:oracle:thin:HR/hr@localhost:5221/myservice"
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The last two signatures inherit an existing database connection. When you inherit a
connection, you will also inherit the auto-commit setting of that connection.
Following is an example of constructing a DefaultContext instance:
DefaultContext defctx = new DefaultContext
("jdbc:oracle:thin:@localhost:5221/myservice", "HR", "hr", false);
Notes About Connection Context Constructors:
Note:
You must keep the following in mind when using connection context
constructors:
• It is important to note that connection context class constructors, unlike
the Oracle.connect() method, require an auto-commit setting.
• To use any of the first three constructors listed, you must first register
your JDBC driver. This happens automatically if you are using an Oracle
JDBC driver and call Oracle.connect(). Refer to "Driver Selection and
Registration for Run Time".
• Connection context classes that you declare generally have the same
constructor signatures as the DefaultContext class. However, if you
declare a connection context class to be associated with a data source,
a different set of constructors is provided. Refer to "Standard Data
Source Support" for more information.
• When using the constructor that takes a JDBC connection object, do not
initialize the connection context instance with a null JDBC connection.
• The auto-commit setting determines whether SQL operations are
automatically committed. Refer to "Basic Transaction Control" for more
information.
Optional DefaultContext close() Method Parameters

When you close a connection context instance, you have the option of specifying
whether or not to close the underlying physical connection. By default it is closed.
This is relevant if you are sharing the physical connection between multiple connection
objects, either SQLJ connection context instances or JDBC connection instances. The
following examples presume a DefaultContext instance defctx.
To keep the underlying physical connection open, use the following:

defctx.close(ConnectionContext.KEEP_CONNECTION);
To close the underlying physical connection, which is the default behavior, use the
following:
defctx.close(ConnectionContext.CLOSE_CONNECTION);
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ConnectionContext interface.
See Also:
"Closing Shared Connections" for more information about using these
parameters and about shared connections
4.2.6 Connection for Translation

If you want to use online semantics-checking during translation, then you must specify
a database connection for SQLJ to use. These are referred to as exemplar schemas.
See Also:
"Connection Context Concepts"
You can use different connections for translation and run time. In fact, it is often
necessary or preferable to do so. It might be necessary if you are not developing the
application in the same kind of environment that it will run in. But even if the run-time
connection is available during translation, it might be preferable to create an account
with a narrower set of resources so that your online checking will be tighter. This would
be true if your application uses only a small subset of the SQL entities available in
the run-time connection. Your online checking would be tighter and more meaningful if
you create an exemplar schema consisting only of SQL entities that your application
actually uses.
Use the SQLJ translator connection options, either on the command line or in a
properties file, to specify a connection for translation.
See Also:
4.2.7 Connection for Customization

Generally, Oracle customization does not require a database connection. However, the
Oracle SQLJ implementation does support customizer connections. This is useful in
two circumstances:
• If you are using Oracle customizer with the optcols option enabled, then a
connection is required. This option allows iterator column type and size definitions
for performance optimization.
• If you are using SQLCheckerCustomizer, a specialized customizer that performs
semantics-checking on profiles, then a connection is required if you are using an
online checker, which is true by default.
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NULL-Handling
For Oracle-specific code generation, the SQLJ translator has an -optcols option
with the same functionality. The SQLCheckerCustomizer is invoked through Oracle
customizer harness verify option. Use the customizer harness user, password, url,
and driver options to specify connection parameters for whatever customizer you are
using, as appropriate.
See Also:
• "Oracle Customizer Column Definition Option (optcols)".

• "SQLCheckerCustomizer for Profile Semantics-Checking"
• "Customizer Harness Options for Connections"
4.3 NULL-Handling
Java primitive types, such as int, double, or float, cannot have null values. You must
consider this in choosing your result expression and host expression types.
• Wrapper Classes for NULL-Handling
• Examples of NULL-Handling
4.3.1 Wrapper Classes for NULL-Handling

SQLJ consistently enforces retrieving SQL NULL as Java null, in contrast to JDBC,
which retrieves NULL as 0 or false for certain data types. Therefore, do not use Java
primitive types in SQLJ for output variables in situations where a SQL NULL may be
received, because Java primitive types cannot take null values.
This pertains to result expressions, output or input-output host expressions, and

iterator column types. If the receiving Java type is primitive and an attempt is made
to retrieve a SQL NULL, then a sqlj.runtime.SQLNullException is thrown and no
assignment is made.
To avoid the possibility of NULL being assigned to Java primitives, use the following
wrapper classes instead of primitive types:
• java.lang.Boolean
• java.lang.Byte
• java.lang.Short
• java.lang.Integer
• java.lang.Long
• java.lang.Double
• java.lang.Float
In case you must convert back to a primitive value, each of these wrapper classes
has an xxxValue() method. For example, intValue() returns an int value from an
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Integer object and floatValue() returns a float value from a Float object. For
example, presuming intobj is an Integer object:
int j = intobj.intValue();
Note:
• SQLNullException is a subclass of the standard java.sql.SQLException

class.
• Because Java objects can have null values, there is no need for
indicator variables in SQLJ, such as those used in other host languages
like C, C++, and COBOL.
4.3.2 Examples of NULL-Handling

The following examples show the use of the java.lang wrapper classes to handle
NULL.
Example: Null Input Host Variable

In the following example, a Float object is used to pass a null value to the database:
int empno = 7499;
Float commission = null;
#sql { UPDATE employees SET commission_pct = :commission WHERE employee_id

= :empno };
You cannot use the Java primitive type float to accomplish this.
Example: Null Iterator Rows

In the following example, a Double column type is used in an iterator to allow for the
possibility of null data.
For each employee in the employee table whose salary is at least $50,000, the
employee name (FIRST_NAME) and commission (COMMISSION_PCT) are selected into the
iterator. Then each row is tested to determine if the COMMISSION_PCT field is, in fact,
null. If so, then it is processed accordingly.
#sql iterator EmployeeIter (String first_name, Double commission);
EmployeeIter ei;
#sql ei = { SELECT first_name, commission_pct FROM employees WHERE salary >=
50000 };
while (ei.next())
{
if (ei.commission_pct() == null)
System.out.println(ei.first_name() + " is not on commission.");
}
ei.close();
...
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Exception-Handling Basics
Note:
To execute a WHERE clause comparison against NULL, use the following SQL
syntax:
...WHERE :x IS NULL
4.4 Exception-Handling Basics

This section covers the basics of handling exceptions in SQLJ application, including
requirements for error-checking. This section covers the following topics:
• SQLJ and JDBC Exception-Handling Requirements
• Processing Exceptions
• Using SQLException Subclasses
4.4.1 SQLJ and JDBC Exception-Handling Requirements

Because SQLJ executable statements result in JDBC calls through sqlj.runtime,
and JDBC requires SQL exceptions to be caught or thrown, SQLJ also requires
SQL exceptions to be caught or thrown in any block containing SQLJ executable
statements. Your source code will generate errors during compilation if you do not
include appropriate exception-handling.
Handling SQL exceptions requires the SQLException class, which is included in the
standard JDBC java.sql.* package.
Example: Exception Handling

This example demonstrates the basic exception-handling required in SQLJ
applications. The code declares a main method with a try/catch block and another
method, which throws SQLException when an exception is encountered. The code is
as follows:
/* Import SQLExceptions class. The SQLException comes from
JDBC. Executable #sql clauses result in calls to JDBC, so methods
containing executable #sql clauses must either catch or throw
SQLException.
*/
import java.sql.* ;
import oracle.sqlj.runtime.Oracle;
// iterator for the select
#sql iterator MyIter (String ITEM_NAME);
public class TestInstallSQLJ

{
//Main method
public static void main (String args[])
{
try {
// Set the default connection to the URL, user, and password
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// specified in your connect.properties file

Oracle.connect(TestInstallSQLJ.class, "connect.properties");
TestInstallSQLJ ti = new TestInstallSQLJ();
// This method throws SQLException. Therefore, it ic called within a try

block
ti.runExample();
} catch (SQLException e) {
System.err.println("Error running the example: " + e);
}
} //End of method main
//Method that runs the example

void runExample() throws SQLException
{
//Issue SQL command to clear the SALES table
#sql { DELETE FROM SALES };
#sql { INSERT INTO SALES(ITEM_NAME) VALUES ('Hello, SQLJ!')};
MyIter iter;
#sql iter = { SELECT ITEM_NAME FROM SALES };
while (iter.next()) {
System.out.println(iter.ITEM_NAME());
}
}
}
4.4.2 Processing Exceptions

This section discusses ways to process and interpret exceptions in your SQLJ
application. During run time, exceptions may be raised from any of the following:
• SQLJ run time
• JDBC driver
• RDBMS
Printing Error Text

The example in the previous section showed how to catch SQL exceptions and output
the error messages. Part of that code is as follows:
...
try {
...
}
...
This will print the error text from the SQLException object.
You can also retrieve error information using the getMessage(), getErrorCode(), and
getSQLState() methods the SQLException class.
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Printing the error text, as in this example, prints the error message with some
additional text, such as SQLException.
Retrieving SQL States and Error Codes

The java.sql.SQLException class and subclasses include the getMessage(),
getErrorCode(), and getSQLState() methods. Depending on where the exception or
error originated and how they are implemented there, the following methods provide
additional information:
• String getMessage()
If the error originates in the SQLJ run time or JDBC driver, then this method
returns the error message with no prefix. If the error originates in the RDBMS, then
it returns the error message prefixed by the ORA number.
• int getErrorCode()
If the error originates in the SQLJ run time, then this method returns no meaningful
information. If the error originates in the JDBC driver or RDBMS, then it returns the
five-digit ORA number as an integer.
• String getSQLState()
If the error originates in the SQLJ run time, then this method returns a string with
a five-digit code indicating the SQL state. If the error originates in the JDBC driver,
then it returns no meaningful information. If the error originates in the RDBMS,
then it returns the five-digit SQL state. Your application should have appropriate
code to handle null values returned.
The following example prints the error message and also checks the SQL state:
...
try {
...
String sqlState = e.getSQLState();
System.err.println("SQL state = " + sqlState);
}
...
4.4.3 Using SQLException Subclasses

For more specific error-checking, use any available and appropriate subclasses of the
java.sql.SQLException class.
SQLJ provides the sqlj.runtime.NullException class, which is a subclass of

java.sql.SQLException. You can use this exception in situations where a NULL might
be returned into a Java primitive variable.
For batch-enabled environments, there is also the standard
java.sql.BatchUpdateException subclass. Refer to "Error Conditions During Batch
Execution" for further information.
When you use a subclass of SQLException, catch the subclass exception before
catching SQLException, as in the following example:
...
try {
...
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} catch (SQLNullException ne) {

System.err.println("Null value encountered: " + ne); }
catch (SQLException e) {
System.err.println("Error running the example: " + e); }
...
This is because a subclass exception can also be caught as a SQLException. If you

catch SQLException first, then execution will not proceed to the part where you have
coded special processing for the subclass exception.
4.5 Basic Transaction Control

This section discusses how to manage data updates. It covers the following topics:
• Overview of Transactions
• Automatic Commits Versus Manual Commits
• Specifying Auto-Commit as You Define a Connection
• Modifying Auto-Commit in an Existing Connection
• Using Manual COMMIT and ROLLBACK
• Effect of Commits and Rollbacks on Iterators and Result Sets
• Using Savepoints
See Also:
"Advanced Transaction Control"
4.5.1 Overview of Transactions

A transaction is a sequence of SQL operations that Oracle treats as a single unit. A
transaction begins with the first executable SQL statement after any of the following:
• Connection to the database
• COMMIT (committing data updates, either automatically or manually)
• ROLLBACK (canceling data updates)
A transaction ends with a COMMIT or ROLLBACK operation.
Note:
In Oracle Database 12c Release 2 (12.2), all data definition language (DDL)
statements, such as CREATE and ALTER, include an implicit COMMIT. This will
commit not only the DDL statement, but all the preceding data manipulation
language (DML) statements, such as INSERT, DELETE, and UPDATE, that have
not yet been committed or rolled back.
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4.5.2 Automatic Commits Versus Manual Commits

In using SQLJ or JDBC, you can either have your data updates automatically
committed or commit them manually. In either case, each COMMIT operation starts a
new transaction. You can specify that changes be committed automatically by enabling
the auto-commit flag. This can be done either when you define a SQLJ connection or
by using the setAutoCommit() method of the underlying JDBC connection object of an
existing connection. You can use manual control by disabling the auto-commit flag and
using SQLJ COMMIT and ROLLBACK statements.
Enabling auto-commit may be more convenient, but gives you less control. For
example, you have no option to roll back changes. In addition, some SQLJ or JDBC
features are incompatible with auto-commit mode. For example, you must disable the
auto-commit flag for update batching or SELECT FOR UPDATE syntax to work properly.
4.5.3 Specifying Auto-Commit as You Define a Connection

When you use the Oracle.connect() or Oracle.getConnection() method to create a
DefaultContext instance and define a connection, the auto-commit flag is set to false
by default. However, there are signatures of these methods that enable you to set this
flag explicitly. The auto-commit flag is always the last parameter.
The following is an example of instantiating DefaultContext and using the default
false setting for auto-commit mode:
Oracle.getConnection
("jdbc:oracle:thin:@localhost:5221/myservice", "HR", "hr");
Alternatively, you can specify a true setting as follows:

Oracle.getConnection
("jdbc:oracle:thin:@localhost:5221/myservice", "HR", "hr", true);
See Also:
"More About the Oracle Class"
If you use a constructor to create a connection context instance, either of

DefaultContext or of a declared connection context class, then you must specify the
auto-commit setting. Again, it is the last parameter, as in the following example:
DefaultContext ctx = new DefaultContext
See Also:
"More About the DefaultContext Class"
If you have reason to create a JDBC Connection instance directly, then the auto-
commit flag is set to true by default if your program runs on a client, or false by
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default if it runs in the server. You cannot specify an auto-commit setting when you
create a JDBC Connection instance directly, but you can use the setAutoCommit()
method to alter the setting.
Note:
Auto-commit functionality is not supported by the JDBC server-side internal
driver.
4.5.4 Modifying Auto-Commit in an Existing Connection

There is typically no reason to change the auto-commit flag setting for an existing
connection, but you can if you desire. You can do this by using the setAutoCommit()
method of the underlying JDBC connection object.
You can retrieve the underlying JDBC connection object by using the getConnection()
method of any SQLJ connection context instance, whether it is an instance of the
DefaultContext class or of a connection context class that you declared.
You can accomplish these two steps at once, as follows:

ctx.getConnection().setAutoCommit(false);
or:
ctx.getConnection().setAutoCommit(true);
In these examples, ctx is a SQLJ connection context instance.
Note:
Do not alter the auto-commit setting in the middle of a transaction.
4.5.5 Using Manual COMMIT and ROLLBACK

If you disable the auto-commit flag, then you must manually commit any data updates.
To commit any changes that have been executed since the last COMMIT operation, use
the SQLJ COMMIT statement, as follows:
#sql { COMMIT };
To roll back any changes that have been executed since the last COMMIT operation, use
the SQLJ ROLLBACK statement, as follows:
#sql { ROLLBACK };
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Note:
• Do not use the COMMIT and ROLLBACK commands when auto-commit is

enabled. This will result in unspecified behavior, or even SQL exceptions
could be raised.
• You can also roll back to a specified savepoint. Refer to "Using
Savepoints".
• All DDL statements in Oracle SQL syntax include an implicit COMMIT
operation. There is no special SQLJ functionality in this regard. Such
statements follow standard Oracle SQL rules.
• If auto-commit mode is off and you close a connection context instance
from a client application, then any changes since your last COMMIT
will be committed, unless you close the connection context instance
with KEEP_CONNECTION. Refer to "Closing Shared Connections" for more
information.
4.5.6 Effect of Commits and Rollbacks on Iterators and Result Sets

COMMIT and ROLLBACK operations do not affect open result sets and iterators. The result
sets and iterators will still be open. Usually, all that is relevant to their content is the
state of the database at the time of execution of the SELECT statements that populated
them.
Note:
An exception to this is if you declared an iterator class with
sensitivity=SENSITIVE. In this case, changes to the underlying result set
may be seen whenever the iterator is scrolled outside of its window size.
For more information about scrollable iterators, refer to "Scrollable Iterators".
For more information about the underlying scrollable result sets, refer to the
Oracle Database JDBC Developer's Guide.
This also applies to UPDATE, INSERT, and DELETE statements that are executed after the
SELECT statements. Execution of these statements does not affect the contents of open
result sets and iterators.
Consider a situation where you SELECT, then UPDATE, and then COMMIT. A nonsensitive
result set or iterator populated by the SELECT statement will be unaffected by the
UPDATE and COMMIT.
As a further example, consider a situation where you UPDATE, then SELECT, and then
ROLLBACK. A nonsensitive result set or iterator populated by the SELECT will still contain
the updated data, regardless of the subsequent ROLLBACK.
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4.5.7 Using Savepoints

The JDBC 3.0 specification added support for savepoints. A savepoint is a defined
point in a transaction that you can roll back to, if desired, instead of rolling back the
entire transaction. The savepoint is the point in the transaction where the SAVEPOINT
statement appears.
In Oracle9i Database Release 2 (9.2), SQLJ first included Oracle-specific syntax to
support savepoints. In Oracle Database 12c Release 2 (12.2), SQLJ adds support for
ISO SQLJ standard savepoint syntax.
Support for ISO SQLJ Standard Savepoint Syntax

In ISO SQLJ standard syntax, use a string literal in a SAVEPOINT statement to
designate a name for a savepoint. This can be done as follows:
#sql { SAVEPOINT savepoint1 };
If you want to roll back changes to that savepoint, then you can refer to the specified
name later in a ROLLBACK TO statement, as follows:
#sql { ROLLBACK TO savepoint1 };
Use a RELEASE SAVEPOINT statement if you no longer need the savepoint:

#sql { RELEASE SAVEPOINT savepoint1 };
Savepoints are saved in the SQLJ execution context, which has methods that parallel
the functionality of these three statements.
See Also:
"Savepoint Methods"
Because any COMMIT operation ends the transaction, this also releases all savepoints
of the transaction.
Oracle SQLJ Savepoint Syntax

In addition to the ISO SQLJ standard syntax, the following Oracle-specific syntax for
savepoints is supported. Note that the Oracle syntax uses string host expressions,
rather than string literals.
You can set a savepoint as follows:
#sql { SET SAVEPOINT :savepoint };
The host expression, savepoint in this example, is a variable that specifies the name
of the savepoint as a Java String.
You can roll back to a savepoint as follows:

#sql { ROLLBACK TO :savepoint };
To release a savepoint, use the following SQLJ statement:
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Summary: First Steps in SQLJ Code
#sql { RELEASE :savepoint };
Note:
Oracle-specific syntax will continue to be supported for backward
compatibility. Note the following differences between Oracle syntax and ISO
SQLJ standard syntax:
• Oracle syntax takes string variables rather than string literals.
• Oracle syntax uses SET SAVEPOINT instead of SAVEPOINT.
• Oracle syntax uses RELEASE instead of RELEASE SAVEPOINT.
4.6 Summary: First Steps in SQLJ Code

The best way to summarize the SQLJ executable statement features and functionality
discussed to this point is by examining short but complete programs. This section
presents two such examples.
The first example, presented one step at a time and then again in its entirety, uses a
SELECT INTO statement to perform a single-row query of two columns from a table of
employees. If you want to run the example, ensure that you change the parameters
in the connect.properties file to settings that will let you connect to an appropriate
database.
The second example, slightly more complicated, will make use of a SQLJ iterator for a
multi-row query.
Import Required Classes

Import any JDBC or SQLJ packages you will need. You will need at least some of the
classes in the java.sql package:
import java.sql.*;
You may not need all the java.sql package. Key classes are java.sql.SQLException
and any classes that you refer to explicitly. For example, java.sql.Date and
java.sql.ResultSet.
You will need the following package for the Oracle class, which you typically use to
instantiate DefaultContext objects and establish your default connection:
import oracle.sqlj.runtime.*;
If you will be using any SQLJ run-time classes directly in your code, then import the
following packages:
import sqlj.runtime.*;
import sqlj.runtime.ref.*;
However, even if your code does not use any SQLJ run-time classes directly, it will be
sufficient to have them in the CLASSPATH.
Key run-time classes include ResultSetIterator and ExecutionContext in the

sqlj.runtime package and DefaultContext in the sqlj.runtime.ref package.
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Register JDBC Drivers and Set Default Connection

Declare the SimpleExample class with a constructor that uses the static
Oracle.connect() method to set the default connection. This also registers Oracle
JDBC drivers.
This uses a signature of connect() that takes the URL, user name, and password
from the connect.properties file. An example of this file is in the directory
ORACLE_HOME/sqlj/demo and also in "Set Up the Run-Time Connection".
public class SimpleExample {
public SimpleExample() throws SQLException {

// Set default connection (as defined in connect.properties).
Oracle.connect(getClass(), "connect.properties");
}
Set Up Exception Handling

Create a main() that calls the SimpleExample constructor and then sets up a try/
catch block to handle any SQL exceptions thrown by the runExample() method, which
performs the real work of this application:
...
public static void main (String [] args) {
try {
SimpleExample o1 = new SimpleExample();
o1.runExample();
}
catch (SQLException ex) {
System.err.println("Error running the example: " + ex);
}
}
...
You can also use a try/catch block inside a finally clause when you close the
connection, presuming the finally clause is not already inside a try/catch block in
case of SQL exceptions:
finally
{
try { Oracle.close(); } catch(SQLException ex) {...}
}
Set Up Host Variables, Execute SQLJ Clause, Process Results

Create a runExample() method that performs the following:
1. Throws any SQL exceptions to the main() method for processing.

2. Declares Java host variables.
3. Executes a SQLJ clause that binds the Java host variables into an embedded
SELECT statement and selects the data into the host variables.
4. Prints the results.
The code for this method is as follows:
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void runExample() throws SQLException {
System.out.println( "Running the example--" );
// Declare two Java host variables--

Float salary;
String empname;
// Use SELECT INTO statement to execute query and retrieve values.

#sql { SELECT first_name, salary INTO :empname, :salary FROM employees
WHERE employee_id = 7499 };
// Print the results--

System.out.println("Name is " + empname + ", and Salary is " + salary);
}
} // Closing brace of SimpleExample class
This example declares salary and empname as Java host variables. The SQLJ clause
then selects data from the first_name and salary columns of the employees table and
places the data into the host variables. Finally, the values of salary and empname are
printed.
Note that this SELECT statement could select only one row of the employees table,
because the employee_id column in the WHERE clause is the primary key of the table.
Example of Single-Row Query using SELECT INTO

This section presents the entire SimpleExample class from the previous step-by-step
sections. Because this is a single-row query, no iterator is required.
// Import SQLJ classes:
// Import standard java.sql package:

import java.sql.*;
public class SimpleExample {
public SimpleExample() throws SQLException {

}
public static void main (String [] args) throws SQLException {
try {
SimpleExample o1 = new SimpleExample();
o1.runExample();
}
catch (SQLException ex) {
System.err.println("Error running the example: " + ex);
}
}
finally
{
}
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System.out.println( "Running the example--" );
// Declare two Java host variables--

Float salary;
String empname;
// Use SELECT INTO statement to execute query and retrieve values.

#sql { SELECT first_name, salary INTO :empname, :salary FROM employees
WHERE employee_id = 7499 };
// Print the results--

System.out.println("Name is " + empname + ", and Salary is " + salary);
}
}
Set Up a Named Iterator

This example builds on the previous example by adding a named iterator and using it
for a multiple-row query.
First, declare the iterator class. Use object types Integer and Float, instead of
primitive types int and float, wherever there is the possibility of NULL values.
#sql iterator EmpRecs(
int empno, // This column cannot be null, so int is OK.
// (If null is possible, use Integer.)
String ename,
String job,
Integer mgr,
Date hiredate,
Float sal,
Float comm,
int deptno);
Next, instantiate the EmpRecs class and populate it with query results.
EmpRecs employees;
#sql employees = { SELECT employee_id, first_name, job_id, manager_id, hire_date,

salary, commission_pct, department_tno FROM employees };
Then, use the next() method of the iterator to print the results.
while (employees.next()) {
System.out.println( "Name: " + employees.first_name() );
System.out.println( "EMPNO: " + employees.employee_id() );
System.out.println( "Job: " + employees.job_id() );
System.out.println( "Manager: " + employees.manager_id) );
System.out.println( "Date hired: " + employees.hire_date() );
System.out.println( "Salary: " + employees.salary() );
System.out.println( "Commission: " + employees.commission_pct() );
System.out.println( "Department: " + employees.department_no() );
System.out.println();
}
Finally, close the iterator.

employees.close();
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Example of Multiple-Row Query Using Named Iterator

This example uses a named iterator for a multiple-row query that selects several
columns of data from a table of employees.
Apart from use of the named iterator, this example is conceptually similar to the
previous single-row query example.
// Import SQLJ classes:
// Import standard java.sql package:

import java.sql.*;
// Declare a SQLJ iterator.

// Use object types (Integer, Float) for mgr, sal, And comm rather
// than primitive types to allow for possible null selection.
#sql iterator EmpRecs(

int empno, // This column cannot be null, so int is OK.
// (If null is possible, Integer is required.)
String ename,
String job,
Integer mgr,
Date hiredate,
Float sal,
Float comm,
int deptno);
// This is the application class.

public class EmpDemo1App {
public EmpDemo1App() throws SQLException {

}
public static void main(String[] args) {
try {
EmpDemo1App app = new EmpDemo1App();
app.runExample();
}
catch( SQLException exception ) {
System.err.println( "Error running the example: " + exception );
}
}
finally
{
}

System.out.println("\nRunning the example.\n" );
// The query creates a new instance of the iterator and stores it in

// the variable 'employees' of type 'EmpRecs'. SQLJ translator has
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Oracle-Specific Code Generation (No Profiles)
// automatically declared the iterator so that it has methods for

// accessing the rows and columns of the result set.
EmpRecs employees;
#sql employees = { SELECT employee_id, first_name, job_id, manager_id,

hire_date,
salary, commission_pct, department_no FROM employees };
// Print the result using the iterator.
// Note how the next row is accessed using method 'next()', and how
// the columns can be accessed with methods that are named after the
// actual database column names.
while (employees.next()) {
System.out.println( "Name: " + employees.first_name() );
System.out.println( "EMPNO: " + employees.employee_id() );
System.out.println( "Job: " + employees.job_id() );
System.out.println( "Manager: " + employees.manager_id() );
System.out.println( "Date hired: " + employees.hire_date() );
System.out.println( "Salary: " + employees.salary() );
System.out.println( "Commission: " + employees.commission_pct() );
System.out.println( "Department: " + employees.department_no() );
System.out.println();
}
// You must close the iterator when it's no longer needed.

employees.close() ;
}
}
4.7 Oracle-Specific Code Generation (No Profiles)

Throughout this manual there is general and standard discussion of the SQLJ run-
time layer and SQLJ profiles. However, the Oracle SQLJ implementation, by default,
generates Oracle-specific code with direct calls to Oracle JDBC driver instead of
generating ISO SQLJ standard code that calls the SQLJ run time. With Oracle-specific
code generation, there are no profile files, and the role of the SQLJ run-time layer
is greatly reduced during program execution. Oracle-specific code supports all Oracle-
specific extended features.
Code generation is determined through the SQLJ translator -codegen option. The
default setting for Oracle-specific code generation is -codegen=oracle. Alternatively,
you can set -codegen=iso for code generation according to the ISO SQLJ standard.

• Code Considerations and Limitations with Oracle-Specific Code Generation
• SQLJ Usage Changes with Oracle-Specific Code Generation
• Advantages and Disadvantages of Oracle-Specific Code Generation
4.7.1 Environment Requirements for Oracle-Specific Code Generation

Be aware of the following requirements of your environment if you use Oracle-specific
code generation:
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• You must use an Oracle11g or later version of JDBC driver, because Oracle-
specific code generation requires JDBC statement caching functionality.
• The generic SQLJ run time library, runtime, is not supported for Oracle-specific
code generation. You must have one of the following Oracle SQLJ run time
libraries in the CLASSPATH:
– runtime12.jar
– runtime12ee.jar
See Also:
4.7.2 Code Considerations and Limitations with Oracle-Specific Code

Generation
When coding a SQLJ application where Oracle-specific code generation will be used,
be aware of the following programming considerations and restrictions:
• To use a nondefault statement cache size, you must include appropriate method
calls in your code, because Oracle customizer stmtcache option is unavailable.
• Do not mix Oracle-specific generated code with ISO SQLJ standard generated
code in the same application. However, if Oracle-specific code and ISO SQLJ
standard code must share the same connection, do one of the following:
– Ensure that the Oracle-specific code and ISO standard code use different
SQLJ execution context instances. Refer to "Execution Contexts" for
information about SQLJ execution contexts.
– Place a transaction boundary, that is, as a manual COMMIT or ROLLBACK
statement, between the two kinds of code.
This limitation regarding mixing code is especially significant for server-side code,
because all Java code running in a given session uses the same JDBC connection
and SQLJ connection context.
• Do not rely on side effects in parameter expressions when values are returned
from the database. Oracle-specific code generation does not create temporary
variables for evaluation of OUT parameters, IN OUT parameters, SELECT INTO
variables, or return arguments on SQL statements.
For example, avoid statements such as the following:
#sql { SELECT * FROM EMPLOYEES INTO :(x[i++]), :(f_with_sideffect()[i++]),
:(a.b[i]) };
or:
#sql x[i++] = { VALUES f(:INOUT (x[i++]), :OUT (f_with_sideffect())) };
Evaluation of arguments is performed in place in the generated code. This

may result in different behavior than when evaluation is according to ISO SQLJ
standards.
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• Type maps for Oracle object functionality assumes that the corresponding Java
classes implement the java.sql.SQLData interface. If you use type maps for
Oracle object functionality, then your iterator declarations and connection context
declarations must specify the same type maps. Specify this through the with
clause.
For example, if you declare a connection context class as follows:
#sql context TypeMapContext with (typeMap="MyTypeMap");
and you populate an iterator instance from a SQLJ statement that uses an
instance of this connection context class, as follows:
TypeMapContext tmc = new TypeMapContext(...);
...
MyIterator it;
#sql [tmc] it = ( SELECT pers, addr FROM tab WHERE ...);
then the iterator declaration is required to have specified the same type map, as
follows:
#sql iterator MyIterator with (typeMap="MyTypeMap")
(Person pers, Address addr);
See Also:
"Custom Java Class Requirements" and "Declaration WITH Clause"
Note:
The reason for this restriction is that with Oracle-specific code
generation, all iterator getter methods are fully generated as Oracle
JDBC calls during translation. To generate the proper calls, the SQLJ
translator must know whether an iterator will be used with a particular
type map.
4.7.3 SQLJ Usage Changes with Oracle-Specific Code Generation

Some options that were previously available only as Oracle customizer options are
useful with Oracle-specific code generation as well. Because profile customization is
not applicable with Oracle-specific code generation, these options have been made
available through other means.
To alter the statement cache size or disable statement caching when generating
Oracle-specific code, use method calls in your code instead of using the customizer
stmtcache option. The sqlj.runtime.ref.DefaultContext class, as well as any
connection context class you declare, now has the following static methods:
• setDefaultStmtCacheSize(int)
• int getDefaultStmtCacheSize()
It also has the following instance methods:
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• setStmtCacheSize(int)
• int getStmtCacheSize()
By default, statement caching is enabled.
See Also:
"Statement Caching"
In addition, the following options are available as front-end Oracle SQLJ translator
options as well as Oracle customizer options:
• -optcols: Enable iterator column type and size definitions to optimize
performance.
• -optparams: Enable parameter size definitions to optimize JDBC resource
allocation. This option is used in conjunction with optparamdefaults.
• -optparamdefaults: Set parameter size defaults for particular data types. This
option is used in conjunction with optparams.
• -fixedchar: Enable CHAR comparisons with blank padding for WHERE clauses.
See Also:
"Options for Code Generation_ Optimizations_ and CHAR Comparisons"
Be aware of the following:

• Use the -optcols option only if you are using online semantics-checking,
where you have used the SQLJ translator -user, -password, and -url options
appropriately to request a database connection during translation.
• The functionality of the -optcols, -optparams, and -optparamdefaults options,
including default values, is the same as for the corresponding customizer options.
4.7.4 Advantages and Disadvantages of Oracle-Specific Code

Generation
Oracle-specific code generation offers following advantages over ISO standard code
generation:
• Applications run more efficiently. The code calls JDBC application programming
interfaces (APIs) directly, placing run-time performance directly at the JDBC
level. The role of the intermediate SQLJ run-time layer is greatly reduced during
program execution.
• Applications are smaller in size.
• No profile files (.ser) are produced. This is especially convenient if you are
loading a translated application into the database or porting it to another system,
because there are fewer components.
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ISO Standard Code Generation
• Translation is faster, because there is no profile customization step.

• During execution, Oracle SQLJ run time and Oracle JDBC driver use the
same statement cache resources, so partitioning resources between the two is
unnecessary.
• Having the SQL-specific information appear in the Java class files instead of in
separate profile files avoids potential security issues.
• You need not have to rewrite your code to take advantage of possible
future Oracle JDBC performance enhancements, such as enhancements being
considered for execution of static SQL code. Future releases of Oracle SQLJ
translator will handle this automatically.
• The use of Java reflection at run time is eliminated, and thus, provides full
portability to browser environments.
However. there are a few disadvantages:
• Oracle-specific generated code may not be portable to generic JDBC platforms.
• Profile-specific functionality is not available. For example, you cannot perform
customizations at a later date to use Oracle customizer harness -debug, -verify,
and -print options.
See Also:
"Customizer Harness Options for Connections" and "AuditorInstaller
Customizer for Debugging"
4.8 ISO Standard Code Generation

• Environment Requirements for ISO Standard Code Generation
• SQLJ Translator and SQLJ Run Time
• SQLJ Profiles
• SQLJ Translation Steps
• Summary of Translator Input and Output
• SQLJ Run-Time Processing
• Deployment Scenarios
4.8.1 Environment Requirements for ISO Standard Code Generation

The Oracle SQLJ implementation, by default, generates Oracle-specific code with
direct calls to Oracle JDBC driver instead of generating ISO standard code that calls
the SQLJ run time. The following is a typical environment setup for ISO standard code
generation:
• SQLJ code generation: -codegen=iso
• SQLJ translation library: translator.jar
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• SQLJ run-time library: runtime12.jar with JDK 6 or JDK 7, and Oracle Database
12c Release 2 (12.2)
• JDBC drivers: Oracle Database 12c Release 2 (12.2)ojdbc6.jar or ojdbc7.jar
• JDK version: JDK 6 or JDK 7
4.8.2 SQLJ Translator and SQLJ Run Time

The following section describes the differences in Oracle SQLJ implementation in case
of ISO standard code generation:
• SQLJ translator: Along with the .java file, the translator also produces one or
more SQLJ profiles for ISO standard code generation. These profiles contain
information about the embedded SQL operations. SQLJ then automatically
invokes a Java compiler to produce .class files from the .java file.
See Also:
"SQLJ Translator Functionality"
• SQLJ run time: For ISO standard code generation, the SQLJ run time implements
the desired actions of the SQL operations by accessing the database using a
JDBC driver. The generic ISO SQLJ standard does not require the SQLJ run time
to use a JDBC driver to access the database.
See Also:
"SQLJ Run Time"SQLJ Run Time
In addition to the translator and run time, there is a component known as the
customizer that plays a role. A customizer tailors SQLJ profiles for a particular
database implementation and vendor-specific features and data types. By default, for
ISO standard code, the SQLJ front end invokes an Oracle customizer to tailor your
profiles for Oracle Database instance and Oracle-specific features and data types.
When you use Oracle customizer during translation, your application will require the
SQLJ run time and an Oracle JDBC driver when it runs.
Note:
Since Oracle Database 10g Release 1, only Oracle JDBC drivers are
supported with SQLJ.
4.8.3 SQLJ Profiles

With ISO standard code generation, SQLJ profiles are serialized Java resources or
classes generated by the SQLJ translator, which contain details about the embedded
SQL statements. The translator creates these profiles. Then, depending on the
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translator option settings, it either serializes the profiles and puts them into binary
resource files or puts them into .class files.

• Overview of Profiles
• Binary Portability
4.8.3.1 Overview of Profiles

SQLJ profiles are used in ISO standard code for implementing the embedded SQL
operations in SQLJ executable statements. Profiles contain information about the SQL
operations and the types and modes of data being accessed. A profile consists of a
collection of entries, where each entry maps to one SQL operation. Each entry fully
specifies the corresponding SQL operation, describing each of the parameters used in
processing this instruction.
SQLJ generates a profile for each connection context class in your application, where
each connection context class corresponds to a particular set of SQL entities you
use in your database operations. There is one default connection context class, and
you can declare additional classes. The ISO SQLJ standard requires that the profiles
be of standard format and content. Therefore, for your application to use vendor-
specific extended features, your profiles must be customized. By default, this occurs
automatically, with your profiles being customized to use Oracle-specific extended
features.
Profile customization enables vendors to add value in the following ways:
• Vendors can support their own specific data types and SQL syntax. For example,
Oracle customizer maps standard JDBC PreparedStatement method calls in
translated SQLJ code to OraclePreparedStatement method calls, which provide
support for Oracle type extensions.
• Vendors can improve performance through specific optimizations.
Note:
• By default, SQLJ profile file names have the .ser extension, but this
does not mean that all .ser files are profiles. Other serialized objects
can use this extension, and a SQLJ program unit can use serialized
objects other than its profiles. Optionally, profiles can be converted
to .class files instead of .ser files.
• A SQLJ profile is not produced if there are no SQLJ executable
statements in the source code.
4.8.3.2 Binary Portability

SQLJ-generated profile files support binary portability. That is, you can port them as is
and use them with other kinds of databases or in other environments, if you have not
used vendor-specific data types or features. This is true for generated .class files as
well.
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4.8.4 SQLJ Translation Steps

For ISO standard code generation (-codegen=iso), the translator processes the SQLJ
source code, converts SQL operations to SQLJ run-time calls, and generates Java
output code and one or more SQLJ profiles. A separate profile is generated for each
connection context class in the source code, where a different connection context
class is typically used for each interrelated set of SQL entities that is used in the
operations.
Generated Java code is put into a .java output file containing the following:
• Any class definitions and Java code from the .sqlj source file
• Class definitions created as a result of the SQLJ iterator and connection context
declarations
See Also:
• A class definition for a specialized class known as the profile-keys class that
SQLJ generates and uses in conjunction with the profiles (for ISO standard SQLJ
code generation only)
• Calls to the SQLJ run time to implement the actions of the embedded SQL
operations
Generated profiles contain information about all the embedded SQL statements in the
SQLJ source code, such as actions to take, data types being manipulated, and tables
being accessed. When the application is run, the SQLJ run time accesses the profiles
to retrieve the SQL operations and passes them to the JDBC driver.
By default, profiles are put into .ser serialized resource files, but SQLJ can optionally
convert the .ser files to .class files as part of the translation.
The compiler compiles the generated Java source file and produces Java .class
files as appropriate. This includes a .class file for each class that is defined, each
of the SQLJ declarations, and the profile-keys class. The JVM then invokes Oracle
customizer or other specified customizer to customize the profiles generated.
See Also:
"Internal Translator Operations"
General SQLJ Notes

Consider the following when translating and running SQLJ applications for ISO specific
code generation:
• Along with compiling existing .java files on the command line and making them
available for type resolution, as for Oracle-specific code generation, you need to:
– Customize the existing profiles
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– Customize the Java Archive (JAR) files containing profiles
See Also:
• SQLJ generates profiles and the profile-keys class only if your source code
includes SQLJ executable statements.
• If you use Oracle customizer during translation, then your application requires
Oracle SQLJ run time and an Oracle JDBC driver when it runs, even if your
code does not use Oracle-specific features. You can avoid this by specifying
-profile=false when you translate, to bypass Oracle-specific customization.
4.8.5 Summary of Translator Input and Output

We have seen what the SQLJ translator takes as input, what it produces as output,
and where it places its output in case of Oracle-specific code generation. This section
covers the same topics for ISO standard code generation:
• Translator Input
• Translator Output
• Output File Locations
See Also:
"Summary of Translator Input and Output"
4.8.5.1 Translator Input

Similar to Oracle -specific code generation, the SQLJ translator takes one or
more .sqlj source files as input, which can be specified on the command line. The
name of the main .sqlj file is based on the public class it defines, if any, else on the
first class it defines.
See Also:
"Translator Input"
4.8.5.2 Translator Output

The translation step produces a Java source file for each .sqlj file in the application
and at least one application profile for ISO standard code generation, presuming the
source code uses SQLJ executable statements.
SQLJ generates Java source files and application profiles as follows:
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See Also:
"Translator Output"
• Similar to Oracle-specific code generation, Java source files are .java files with
the same base names as the .sqlj files.
• The application profile files, if applicable, contain information about the SQL
operations of the SQLJ application. There is one profile for each connection class
that is used in the application. The profiles have names with the same base name
as the main .sqlj file and the following extensions:
_SJProfile0.ser
_SJProfile1.ser
_SJProfile2.ser
...
For example, for MyClass.sqlj the translator produces:

MyClass_SJProfile0.ser
The .ser file extension indicates that the profiles are serialized. The .ser files are
binary files.
Note:
The -ser2class translator option instructs the translator to generate
profiles as .class files instead of .ser files. Other than the file name
extension, the naming is the same.
Similar to the compilation step of Oracle-specific code generation, compiling the Java
source file into multiple class files generates one .class file for each class defined
in the .sqlj source file. But in case of ISO code generation, a .class file is also
generated for a class known as the profile-keys class that the translator generates
and uses with the profiles to implement the SQL operations. Additional .class files
are produced if you declare any SQLJ iterators or connection contexts. Also, like
Oracle-specific code generation, separate .class files are produced for any inner
classes or anonymous classes in the code.
See Also:
The .class files are named as follows:
• Like Oracle-specific code generation, the class file for each class defined consists
of the name of the class with the .class extension.
• The profile-keys class that the translator generates is named according to the
base name of the main .sqlj file, plus the following:
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_SJProfileKeys
So, the class file has the following extension:

_SJProfileKeys.class
For example, for MyClass.sqlj, the translator together with the compiler produces:
MyClass_SJProfileKeys.class
• Like Oracle-specific code generation, the translator names iterator classes and
connection context classes according to how you declare them.
The customization step alters the profiles but produces no additional output.
See Also:
"Profile Customization (ISO Code Generation)"
Note:
It is not necessary to reference SQLJ profiles or the profile-keys class
directly. This is all handled automatically.
4.8.5.3 Output File Locations

The output file locations are the same for both Oracle-specific code generation and
ISO standard code generation.
See Also:
"Output File Locations"
4.8.6 SQLJ Run-Time Processing

This section discusses run-time processing for ISO standard code during program
execution.
For ISO standard SQLJ applications, the SQLJ run time reads the profiles and creates
connected profiles, which incorporate database connections. Then the following
occurs each time the application must access the database:
1. SQLJ-generated application code uses methods in a SQLJ-generated profile-keys
class to access the connected profile and read the relevant SQL operations. There
is a mapping between SQLJ executable statements in the application and SQL
operations in the profile.
2. The SQLJ-generated application code calls the SQLJ run time, which reads the
SQL operations from the profile.
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3. The SQLJ run time calls the JDBC driver and passes the SQL operations to the
driver.
4. The SQLJ run time passes any input parameters to the JDBC driver.
5. The JDBC driver executes the SQL operations.
6. If any data is to be returned, then the database sends it to the JDBC driver, which
sends it to the SQLJ run time for use by your application.
Note:
Passing input parameters can also be referred to as binding input
parameters or binding host expressions. The terms host variables, host
expressions, bind variables, and bind expressions are all used to describe
Java variables or expressions that are used as input or output for SQL
operations.
4.8.7 Deployment Scenarios

We have discussed how to run Oracle-specific SQLJ code in the following scenarios:
• From an applet
• In the server (optionally running the SQLJ translator in the server as well)
There are a few considerations that you need to make while running your ISO
standard code from an applet:
See Also:
"Alternative Deployment Scenarios"
• You must package all the SQLJ run-time packages with your applet. The packages
are:
sqlj.runtime
sqlj.runtime.ref
sqlj.runtime.profile
sqlj.runtime.profile.ref
sqlj.runtime.error
Also package the following if you used Oracle customization:

oracle.sqlj.runtime
oracle.sqlj.runtime.error
These packages are included with your Oracle installation in one of several run-
time libraries in the ORACLE_HOME/lib directory.
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See Also:
• Some browsers, such as Netscape Navigator 4.x, do not support resource files
with a .ser extension, which is the extension used by the SQLJ serialized object
files that are used for profiles. However, the Sun Microsystems Java plug-in
supports .ser files.
Alternatively, if you do not want to use the plug-in, then the Oracle SQLJ
implementation offers the -ser2class option to convert .ser files to .class files
during translation.
Note:
This consideration does not apply to the default Oracle-specific code
generation, where no profiles are produced.
• Applets using Oracle-specific features require Oracle SQLJ run time to work.
Oracle SQLJ run time consists of the classes in the SQLJ run-time library
file under oracle.sqlj.*. Oracle SQLJ runtime.jar library requires the Java
Reflection API, java.lang.reflect.*. Most browsers do not support the
Reflection API or impose security restrictions, but the Sun Microsystems Java
plug-in provides support for the Reflection API.
With ISO standard code generation, the following SQLJ language features always
require the Java Reflection API, regardless of the version of the SQLJ run time
you are using:
– The CAST statement
– REF CURSOR parameters or REF CURSOR columns being retrieved from the
database as instances of a SQLJ iterator
– Retrieval of java.sql.Ref, Struct, Array, Blob, or Clob objects
– Retrieval of SQL objects as instances of Java classes implementing the
oracle.sql.ORAData or java.sql.SQLData interfaces
Note:
* An exception to the preceding is if you use SQLJ in a mode

that is fully compatible with ISO. That is, if you use SQLJ in an
environment that complies with J2EE and you translate and run
your program with the SQLJ runtime12ee.jar library, and you
employ connection context type maps as specified by ISO. In
this case, instances of java.sql.Ref, Struct, Array, Blob, Clob,
and SQLData are being retrieved without the use of reflection.
* If you use Oracle-specific code generation, then you will
eliminate the use of reflection in all of the instances listed.
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Oracle-Specific Code Generation Versus ISO Standard Code Generation
4.9 Oracle-Specific Code Generation Versus ISO Standard

Code Generation
The Oracle SQLJ implementation provides the option of Oracle-specific code
generation, where Oracle JDBC calls are generated directly in the code. This is the
default behavior. In the case of Oracle-specific code generation, you must be aware of
the following:
• There are no profile files, and therefore, there is no customization step during
translation.
• At run time, SQL operations do not have to go through the SQLJ run-time layer,
because JDBC calls, instead of the SQLJ run-time calls, are directly generated in
the translated code.
4.10 Requirements and Restrictions for Naming

There are four areas to consider in discussing naming requirements, naming
restrictions, and reserved words:
• The Java namespace, including additional restrictions imposed by SQLJ on the
naming of local variables and classes
• The SQLJ namespace
• The SQL namespace
• Source file names
• Java Namespace: Local Variable and Class Naming Restrictions
• SQLJ Namespace
• SQL Namespace
• File Name Requirements and Restrictions
4.10.1 Java Namespace: Local Variable and Class Naming

Restrictions
The Java namespace applies to all standard Java statements and declarations,
including the naming of Java classes and local variables. All standard Java naming
restrictions apply, and you should avoid the use of Java reserved words.
In addition, SQLJ places minor restrictions on the naming of local variables and
classes.
Note:
Naming restrictions particular to host variables are discussed in "Restrictions
on Host Expressions".
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Requirements and Restrictions for Naming
Local Variable Naming Restrictions

Some of the functionality of the SQLJ translator results in minor restrictions in naming
local variables. The SQLJ translator replaces each SQLJ executable statement with a
statement block, where the SQLJ executable statement is of the standard syntax:
SQLJ may use temporary variable declarations within a generated statement block.
The name of any such temporary variables will include the following prefix:
__sJT_
Note:
There are two underscores at the beginning and one at the end.
The following declarations are examples of those that might occur in a SQLJ-
generated statement block:
int __sJT_index;
Object __sJT_key;
java.sql.PreparedStatement __sJT_stmt;
The string __sJT_ is a reserved prefix for SQLJ-generated variable names. SQLJ
programmers must not use this string as a prefix for the following:
• Names of variables declared in blocks that include executable SQL statements
• Names of parameters to methods that contain executable SQL statements
• Names of fields in classes that contain executable SQL statements, or whose
subclasses or enclosed classes contain executable SQL statements
Class Naming Restrictions

Be aware of the following minor restrictions in naming classes in SQLJ applications:
• You must not declare class names that may conflict with SQLJ internal classes. In
particular, a top-level class cannot have a name of the following form, where a is
the name of an existing class in the SQLJ application:
a_SJb
where, a and b are legal Java identifiers.

For example, if your application class is Foo in file Foo.sqlj, then SQLJ generates
a profile-keys class called Foo_SJProfileKeys. Do not declare a class name that
conflicts with this.
• A class containing SQLJ executable statements must not have a name that is the
same as the first component of the name of any package that includes a Java type
used in the application. Examples of class names to avoid are java, sqlj, and
oracle (case-sensitive). As another example, if your SQLJ statements use host
variables whose type is abc.def.MyClass, then you cannot use abc as the name
of the class that uses these host variables.
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Requirements and Restrictions for Naming
To avoid this restriction, follow Java naming conventions recommending that

package names start in lowercase and class names start in uppercase.
4.10.2 SQLJ Namespace

The SQLJ namespace refers to #sql class declarations and the portion of #sql
executable statements outside the curly braces.
Note:
Restrictions particular to the naming of iterator columns are discussed in
"Using Named Iterators".
Avoid using the following SQLJ reserved words as class names for declared
connection context classes or iterator classes, in with or implements clauses, or in
iterator column type declaration lists:
• iterator
• context
• with
For example, do not have an iterator class or instance called iterator or a connection
context class or instance called context.
However, note that it is permissible to have a stored function return variable whose
name is any of these words.
4.10.3 SQL Namespace

The SQL namespace refers to the portion of a SQLJ executable statement inside the
curly braces. Standard SQL naming restrictions apply here.
See Also:
Oracle Database SQL Language Reference
However, note that host expressions follow rules of the Java namespace, not the SQL
namespace. This applies to the name of a host variable and to everything between the
outer parentheses of a host expression.
4.10.4 File Name Requirements and Restrictions

SQLJ source files have the .sqlj file name extension. If the source file declares a
public class (maximum of one), then the base name of the file must match the name
of this class (case-sensitive). If the source file does not declare a public class, then the
file name must still be a legal Java identifier, and it is recommended that the file name
match the name of the first defined class.
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Considerations for SQLJ in the Middle Tier
For example, if you define the public class MySource in your source file, then your file
name must be:
MySource.sqlj
Note:
These file naming requirements follow the Java Language Specification
(JLS) and are not SQLJ-specific. These requirements do not directly apply in
Oracle Database 12c Release 2 (12.2), but it is still advisable to adhere to
them.
4.11 Considerations for SQLJ in the Middle Tier

There are special considerations if you run SQLJ in the middle tier, such as in an
Oracle9i Application Server Containers for J2EE (OC4J) environment.
Oracle JDBC drivers provide Oracle-specific interfaces in the oracle.jdbc package.
The Oracle SQLJ libraries runtime12.jar and runtime12ee.jar make full use
of these interfaces, but these libraries are not compatible with Oracle JDBC
implementations prior to Oracle9i Application Server.
In Oracle9i Application Server, connections are established through data sources,
which typically return instances of the oracle.jdbc.OracleConnection interface
instead of the older oracle.jdbc.driver.OracleConnection class. This is necessary
for certain connection functionality, such as distributed transactions (XA). To support
such features, connection objects must implement the new interface.
This has the following consequences, relevant in an Oracle9i Application Server
middle-tier environment, or any situation where data sources are used:
• For maximum portability and flexibility of your code, use oracle.jdbc.OracleXXX
types instead of oracle.jdbc.driver.OracleXXX types.
• For custom Java types (typically for SQL objects and collections), implement
oracle.sql.ORAData.
• Do not use the SQLJ runtime library. Use runtime12 or runtime12ee
instead (depending on your environment). The run time library is backward
compatible with older JDBC drivers, such as those in Oracle8i Database
release 8.1.7, so supports the oracle.jdbc.driver.OracleXXX types, not the
oracle.jdbc.OracleXXX types.
However, if you must use the runtime library for some reason, then
set the option -profile=false during translation. In this case, your
program will not use Oracle-specific customization and, therefore, will not
fail if passed an oracle.jdbc.OracleConnection instance instead of an
oracle.jdbc.driver.OracleConnection instance. In this circumstance, Oracle-
specific features will not be supported.
To facilitate management of connections obtained through data sources
and connection JavaBeans (for SQLJ JavaServer Pages), the Oracle SQLJ
implementation provides a number of APIs in the runtime12ee library.
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Considerations for SQLJ in the Middle Tier
For general information about SQLJ support for data sources and connection
JavaBeans, refer to the following sections:
• "Standard Data Source Support"
• "SQLJ-Specific Data Sources"
• "SQLJ-Specific Connection JavaBeans for JavaServer Pages"
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Basic Language Features
SQLJ statements always begin with a #sql token and can be broken into two main
categories:
• Declarations: Used for creating Java classes for iterators, which is similar to
Java Database Connectivity (JDBC) result sets, or connection contexts, which is
designed to help you create strongly typed connections according to the sets of
SQL entities being used.
• Executable statements: Used to execute embedded SQL operations.
This chapter discusses the following topics:
• Overview of SQLJ Declarations
• Overview of SQLJ Executable Statements
• Java Host_ Context_ and Result Expressions
• Single-Row Query Results: SELECT INTO Statements
• Multirow Query Results: SQLJ Iterators
• Assignment Statements (SET)
• Stored Procedure and Function Calls
5.1 Overview of SQLJ Declarations

A SQLJ declaration consists of the #sql token followed by the declaration of a class.
SQLJ declarations introduce specialized Java types into your application. There are
currently two kinds of SQLJ declarations, iterator declarations and connection context
declarations, defining Java classes as follows:
• Iterator declarations define iterator classes. Iterators are conceptually similar to
JDBC result sets and are used to receive multi-row query data. An iterator is
implemented as an instance of an iterator class.
• Connection context declarations define connection context classes. Each
connection context class is typically used for connections whose operations use a
particular set of SQL entities, such as tables, views, and stored procedures. That
is to say, instances of a particular connection context class are used to connect to
schemas that include SQL entities with the same names and characteristics. SQLJ
implements each database connection as an instance of a connection context
class.
SQLJ includes the predefined sqlj.runtime.DefaultContext connection context
class. If you only require one connection context class, then you can use
DefaultContext, which does not require a connection context declaration.
In any iterator or connection context declaration, you may optionally include the
following clauses:
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Overview of SQLJ Declarations
• The implements clause: Specifies one or more interfaces that the generated class
will implement.
• The with clause: Specifies one or more initialized constants to be included in the
generated class.
• Rules for SQLJ Declarations
• Iterator Declarations
• Connection Context Declarations
• Declaration IMPLEMENTS Clause
• Declaration WITH Clause
5.1.1 Rules for SQLJ Declarations

SQLJ declarations are allowed in your SQLJ source code anywhere that a class
definition would be allowed in standard Java. For example:
SQLJ declaration; // OK (top level scope)
class Outer
{
SQLJ declaration; // OK (class level scope)
class Inner
{
SQLJ declaration; // OK (nested class scope)
}
void func()
{
SQLJ declaration; // OK (method block)
}
}
Note:
As with standard Java, any public class should be declared in one of the
following ways:
• Declare it in a separate source file. The base name of the file should be
the same as the class name.
• Declare it at class-level scope or nested-class-level scope. In this case, it
may be advisable to use public static modifiers.
This is a requirement if you are using the standard javac compiler provided
with the Sun Microsystems JDK.
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5.1.2 Iterator Declarations

An iterator declaration creates a class that defines a kind of iterator for receiving query
data. The declaration will specify the column types of the iterator instances, which
must match the column types being selected from the database table.
Basic iterator declarations use the following syntax:
#sql <modifiers> iterator iterator_classname (type declarations);
Modifiers are optional and can be any standard Java class modifiers, such as public,
static, and so on. Type declarations are separated by commas.
There are two categories of iterators, named iterators and positional iterators. For
named iterators, you must specify column names and types. For positional iterators,
you need to specify only types.
The following is an example of a named iterator declaration:
#sql public iterator EmpIter (String ename, double sal);
This statement results in the SQLJ translator creating a public EmpIter class with a
String attribute ename and a double attribute sal. You can use this iterator to select
data from a database table with corresponding employee name and salary columns of
matching names (ENAME and SAL) and data types (CHAR and NUMBER).
Declaring EmpIter as a positional iterator, instead of a named iterator, can be done as

follows:
#sql public iterator EmpIter (String, double);
See Also:
"Multirow Query Results: SQLJ Iterators"
5.1.3 Connection Context Declarations

A connection context declaration creates a connection context class, whose instances
are typically used for database connections that use a particular set of SQL entities.
Basic connection context declarations use the following syntax:
#sql <modifiers> context context_classname;
As for iterator declarations, modifiers are optional and can be any standard Java class
modifiers. For example:
#sql public context MyContext;
As a result of this statement, the SQLJ translator creates a public MyContext class. In
your SQLJ code you can use instances of this class to create database connections
to schemas that include a desired set of entities, such as tables, views, and stored
procedures. Different instances of MyContext might be used to connect to different
schemas, but each schema might be expected, for example, to include an EMPLOYEES
table, a DEPARTMENTS table, and a SECURE_EMPLOYEES stored procedure.
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Declared connection context classes are an advanced topic and are not necessary
for basic SQLJ applications that use only one interrelated set of SQL entities. In
basic scenarios, you can use multiple connections by creating multiple instances of
the sqlj.runtime.ref.DefaultContext class, which does not require any connection
context declarations.
See Also:
"Connection Considerations" and "Connection Contexts"
5.1.4 Declaration IMPLEMENTS Clause

When you declare any iterator class or connection context class, you can specify one
or more interfaces to be implemented by the generated class.
Use the following syntax for an iterator class:
#sql <modifiers> iterator iterator_classname implements intfc1,..., intfcN
(type declarations);
The portion implements intfc1,..., intfcN is known as the implements clause.

Note that in an iterator declaration, the implements clause precedes the iterator type
declarations.
Here is the syntax for a connection context declaration:
#sql <modifiers> context context_classname implements intfc1,..., intfcN;
The implements clause is potentially useful in either an iterator declaration

or a connection context declaration, but is more likely to be useful in
iterator declarations, particularly in implementing the sqlj.runtime.Scrollable or
sqlj.runtime.ForUpdate interface. Scrollable iterators are supported in the Oracle
SQLJ implementation.
Note:
The SQLJ implements clause corresponds to the Java implements clause.
The following example uses an implements clause in declaring a named iterator class.
Presume you have created a package, mypackage, that includes an iterator interface,
MyIterIntfc.
#sql public iterator MyIter implements mypackage.MyIterIntfc
(String ename, int empno);
The declared class MyIter will implement the mypackage.MyIterIntfc interface.
The following example declares a connection context class that implements an

interface named MyConnCtxtIntfc. Presume that it is in the package mypackage.
#sql public context MyContext implements mypackage.MyConnCtxtIntfc;
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See Also:
"Using the IMPLEMENTS Clause in Iterator Declarations" and "Using the
IMPLEMENTS Clause in Connection Context Declarations"
5.1.5 Declaration WITH Clause

In declaring a connection context class or iterator class, you can use a with clause
to specify and initialize one or more constants to be included in the definition of the
generated class. Most of this usage is standard, although Oracle implementation adds
some extended functionality for iterator declarations.
• Standard WITH Clause Usage
• Oracle-Specific WITH Clause Usage
• Example: Returnability
5.1.5.1 Standard WITH Clause Usage

In using a with clause, the constants that are produced are always public static
final. Use the following syntax for an iterator class:
#sql <modifiers> iterator iterator_classname with (var1=value1,..., varN=valueN)
(type declarations);
The portion with (var1=value1,..., varN=valueN) is the with clause. Note that in an
iterator declaration, the with clause precedes the iterator type declarations.
Where there is both a with clause and an implements clause, the implements clause
must come first. Note that parentheses are used to enclose with lists, but not
implements lists.
Here is the syntax for a connection context declaration that uses a with clause:
#sql <modifiers> context context_classname with (var1=value1,..., varN=valueN);
Note:
A predefined set of standard SQLJ constants can be defined in a with
clause. However, not all of these constants are meaningful to Oracle
Database 12c Release 2 (12.2) or to Oracle SQLJ run time.
Attempts to define constants other than the standard constants is legal
with Oracle Database 12c Release 2 (12.2), but might not be portable to
other SQLJ implementations and will generate a warning if you have the
-warn=portable flag enabled.
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Supported WITH Clause Constants

The Oracle SQLJ implementation supports the following standard constants in
connection context declarations:
• typeMap: a String literal defining the name of a type map properties resource
Oracle also supports the use of typeMap in iterator declarations.
• dataSource: a String literal defining the name under which a data source is
looked up in the InitialContext
The Oracle SQLJ implementation supports the following standard constants in iterator
declarations:
• sensitivity: SENSITIVE/ASENSITIVE/INSENSITIVE, to define the sensitivity of a
scrollable iterator
• returnability: true/false, to define whether an iterator can be returned from a
Java stored procedure or function
Unsupported WITH Clause Constants

If you have SQLJ code that uses these constants, then they will not cause an error
but will result in no operation. The Oracle SQLJ implementation does not support the
following standard constants in connection context declarations:
• path: a String literal defining the name of a path to be prepended for resolution of
Java stored procedures and functions
• transformGroup: a String literal defining the name of a SQL transformation group
that can be applied to SQL types
The Oracle SQLJ implementation does not support the following standard constants,
involving cursor states, in iterator declarations:
• holdability: true/false, determining cursor holdability
The concept of holdability is defined in the SQL specification. A cursor that is
holdable can, subject to application request, be kept open and positioned on the
current row even when a transaction is completed. Use of the cursor can then be
continued in the next transaction of the same SQL session, however, subject to
some limitations.
• updateColumns: a String literal containing a comma-delimited list of column
names
An iterator declaration having a with clause that specifies updateColumns must
also have an implements clause that specifies the sqlj.runtime.ForUpdate
interface. The Oracle SQLJ implementation enforces this, even though
updateColumns is currently unsupported.
The following is a sample connection context declaration using typeMap:
#sql public context MyContext with (typeMap="MyPack.MyClass");
The declared class MyContext will define a String attribute typeMap that will be
public static final and initialized to the value MyPack.MyClass. This value is the
fully qualified class name of a ListResourceBundle implementation that provides the
mapping between SQL and Java types for statements executed on instances of the
MyContext class.
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The following is a sample iterator declaration using sensitivity:

#sql public iterator MyAsensitiveIter with (sensitivity=ASENSITIVE)
This declaration sets the cursor sensitivity to ASENSITIVE for the MyAsensitiveIter
named iterator class.
The following example uses both an implements clause and a with clause:
#sql public iterator MyScrollableIterator implements sqlj.runtime.Scrollable
with (holdability=true) (String ename, int empno);
This declaration implements the interface sqlj.runtime.Scrollable and enables the

cursor holdability for a named iterator class.
Note:
holdability is currently not supported.
5.1.5.2 Oracle-Specific WITH Clause Usage

In addition to the standard with clause usage in a connection context declaration
to associate a type map with the connection context class, the Oracle SQLJ
implementation enables you to use a with clause to associate a type map with the
iterator class in an iterator declaration. For example:
#sql iterator MyIterator with (typeMap="MyTypeMap") (Person pers, Address addr);
If you use Oracle-specific code generation and use type maps in your application, then
your iterator and connection context declarations must use the same type maps.
See Also:
"Code Considerations and Limitations with Oracle-Specific Code Generation"
5.1.5.3 Example: Returnability

Use returnability=true in the with clause of a SQLJ iterator declaration to specify
that the iterator can be returned from a Java stored procedure to a SQL or PL/SQL
statement as a REF CURSOR. With the default returnability=false setting, the
iterator cannot be returned in this manner, and an attempt to do so will result in a SQL
exception at run time.
Create the following database table:
create table sqljRetTab(str varchar2(30));
insert into sqljRetTab values ('sqljRetTabCol');
Define the RefCursorSQLJ class in the RefCursorSQLJ.sqlj source file as follows.

Note that the iterator type MyIter uses returnability=true.
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Overview of SQLJ Executable Statements
public class RefCursorSQLJ

{
#sql static public iterator MyIter with (returnability=true) (String str);
static public MyIter sqljUserRet() throws java.sql.SQLException

{
MyIter iter=null;
try {
#sql iter = {select str from sqljRetTab};
} catch (java.sql.SQLException e)
{
e.printStackTrace();
throw e;
}
System.err.println("iter is " + iter);
return iter;
}
}
Load RefCursorSQLJ.sqlj into Oracle Java Virtual Machine (JVM) inside the database
as follows:
% loadjava -u HR -r -f -v RefCursorSQLJ.sqlj
Password: password
Invoke the Java stored procedure defined for the sqljUserRet() method:
create or replace package refcur_pkg as
type refcur_t is ref cursor;
end;
/
create or replace function sqljUserRet
return refcur_pkg.refcur_t as
language java
name 'RefCursorSQLJ.sqljUserRet() return
RefCursorSQLJ.MyIter';
/
select HR.sqljUserRet from dual;
Here is the result of the SELECT statement:

SQLJRET1
--------------------
CURSOR STATEMENT : 1
STR
------------------------------
sqljRetTabCol
5.2 Overview of SQLJ Executable Statements

A SQLJ executable statement consists of the #sql token followed by a SQLJ clause,
which uses syntax that follows a specified standard for embedding executable SQL
statements in Java code. The embedded SQL operation of a SQLJ executable
statement can be any SQL operation supported by the JDBC driver.
• Rules for SQLJ Executable Statements
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• SQLJ Clauses
• Specifying Connection Context Instances and Execution Context Instances
• Executable Statement Examples
• PL/SQL Blocks in Executable Statements
5.2.1 Rules for SQLJ Executable Statements

A SQLJ executable statement must adhere to the following rules:
• It is permitted in Java code wherever Java block statements are permitted. That is,
it is permitted inside method definitions and static initialization blocks.
• Its embedded SQL operation must be enclosed in curly braces: {...}.
• It must be terminated with a semi-colon (;).
Note:
• It is recommended that you do not close the SQL operation with a semi-
colon. The parser will detect the end of the operation when it encounters
the closing curly brace of the SQLJ clause.
• Everything inside the curly braces of a SQLJ executable statement is
treated as SQL syntax and must follow SQL rules, with the exception of
Java host expressions.
• During offline parsing of SQL operations, all SQL syntax is checked.
However, during online semantics-checking only data manipulation
language (DML) operations can be parsed and checked. Data definition
language (DDL) operations, transaction-control operations, or any other
kinds of SQL operations cannot be parsed and checked.
5.2.2 SQLJ Clauses

A SQLJ clause is the executable part of a statement, consisting of everything to the
right of the #sql token. This consists of embedded SQL inside curly braces, preceded
by a Java result expression if appropriate, such as result in the following example:
#sql { SQL operation }; // For a statement with no output, like INSERT
...
#sql result = { SQL operation }; // For a statement with output, like SELECT
A clause without a result expression, such as in the first SQLJ statement in

the example, is known as a statement clause. A clause that does have a result
expression, such as in the second SQLJ statement in the example, is known as an
assignment clause.
A result expression can be anything from a simple variable that takes a stored-function
return value to an iterator that takes several columns of data from a multi-row SELECT,
where the iterator can be an instance of an iterator class or subclass.
A SQL operation in a SQLJ statement can use standard SQL syntax only or can use a
clause with syntax specific to SQLJ.
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Table 1 lists supported SQLJ statement clauses and Table 2 lists supported SQLJ
assignment clauses. The last two entries in Table 1 are general categories for
statement clauses that use standard SQL syntax or Oracle PL/SQL syntax, as
opposed to SQLJ-specific syntax.
Table 5-1 SQLJ Statement Clauses
Category Functionality More Information

SELECT INTO clause Select data into Java host "Single-Row Query Results: SELECT
expressions. INTO Statements"
FETCH clause Fetch data from a positional "Using Positional Iterators"
iterator.
COMMIT clause Commit changes to the "Using Manual COMMIT and
data. ROLLBACK"
ROLLBACK clause Cancel changes to the "Using Manual COMMIT and
data. ROLLBACK"
SAVEPOINT RELEASE Set a savepoint for "Using Savepoints"
SAVEPOINT ROLLBACK future rollbacks, release
TO clauses a specified savepoint, roll
back to a savepoint.
SET TRANSACTION Use advanced transaction "Advanced Transaction Control"
clause control for access mode
and isolation level.
Procedure clause Call a stored procedure. "Calling Stored Procedures"
Assignment clause Assign values to Java host "Assignment Statements (SET)"
expressions.
SQL clause Use standard SQL syntax Oracle Database SQL Language
and functionality: UPDATE, Reference
INSERT, DELETE.
PL/SQL block Use BEGIN..END or "PL/SQL Blocks in Executable
DECLARE..BEGIN..END Statements"
anonymous block inside Oracle Database PL/SQL Language
SQLJ statement. Reference
Table 5-2 SQLJ Assignment Clauses
Category Functionality More Information

Query clause Select data into a SQLJ "Multirow Query Results: SQLJ Iterators"
iterator.
Function clause Call a stored function. "Calling Stored Functions"
Iterator conversion Convert a JDBC result set "Converting from Result Sets to Named or
clause to a SQLJ iterator. Positional Iterators"
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Note:
A SQLJ statement is referred to by the same name as the clause that
makes up the body of that statement. For example, an executable statement
consisting of #sql followed by a SELECT INTO clause is referred to as a
SELECT INTO statement.
5.2.3 Specifying Connection Context Instances and Execution Context

Instances
If you have defined multiple database connections and want to specify a particular
connection context instance for an executable statement, then use the following
syntax:
#sql [conn_context_instance] { SQL operation };
If you have defined one or more execution context instances of the

sqlj.runtime.ExecutionContext class and want to specify one of them for use with
an executable statement, then use the following syntax:
#sql [exec_context_instance] { SQL operation };
You can use an execution context instance to provide status or control of the SQL
operation of a SQLJ executable statement. For example, you can use execution
context instances in multithreading situations where multiple operations are occurring
on the same connection.
You can also specify both a connection context instance and an execution context
instance:
#sql [conn_context_instance, exec_context_instance] { SQL operation };
Note:
• Include the square brackets around connection context instances and

execution context instances. They are part of the syntax.
• If you specify both a connection context instance and an execution
context instance, then the connection context instance must come first.
5.2.4 Executable Statement Examples

This section provides examples of elementary SQLJ executable statements.
Elementary INSERT
The following example demonstrates a basic INSERT. The statement clause does not
require any syntax specific to SQLJ.
Consider an employee table EMP with the following rows:
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CREATE TABLE EMP (

ENAME VARCHAR2(10),
SAL NUMBER(7,2) );
Use the following SQLJ executable statement, which uses only standard SQL syntax,
to insert Joe as a new employee into the EMP table, specifying his name and salary:
#sql { INSERT INTO emp (ename, sal) VALUES ('Joe', 43000) };
Elementary INSERT with Connection Context or Execution Context Instances

The following examples use ctx as a connection context instance, which is an
instance of either the default sqlj.runtime.ref.DefaultContext or a class that you
have previously declared in a connection context declaration, and execctx as an
execution context instance:
#sql [ctx] { INSERT INTO emp (ename, sal) VALUES ('Joe', 43000) };
#sql [execctx] { INSERT INTO emp (ename, sal) VALUES ('Joe', 43000) };
#sql [ctx, execctx] { INSERT INTO emp (ename, sal) VALUES ('Joe', 43000) };
A Simple SQLJ Method

This example demonstrates a simple method using SQLJ code, demonstrating how
SQLJ statements interrelate with and are interspersed with Java statements. The
SQLJ statement uses standard INSERT INTO table VALUES syntax supported by the
Oracle SQL implementation. The statement also uses Java host expressions, marked
by colons (:), to define the values. Host expressions are used to pass data between
the Java code and SQL instructions.
public static void writeSalesData (int[] itemNums, String[] itemNames)
throws SQLException
{
for (int i =0; i < itemNums.length; i++)
#sql { INSERT INTO sales VALUES(:(itemNums[i]), :(itemNames[i]), SYSDATE) };
}
Note:
• The throws SQLException is required.

• SQLJ function calls also use a VALUES token, but these situations are not
related semantically.
5.2.5 PL/SQL Blocks in Executable Statements

PL/SQL blocks can be used within the curly braces of a SQLJ executable statement
just as SQL operations can, as in the following example:
#sql {
DECLARE
n NUMBER;
BEGIN
n := 1;
WHILE n <= 100 LOOP
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Java Host, Context, and Result Expressions
INSERT INTO emp (empno) VALUES(2000 + n);

n := n + 1;
END LOOP;
END
};
This example goes through a loop that inserts new employees in the emp table,
creating employee numbers 2001 through 2100. It presumes data other than the
employee number will be filled in later.
Simple PL/SQL blocks can also be coded in a single line as follows:
#sql { <DECLARE ...> BEGIN ... END; };
Using PL/SQL anonymous blocks within SQLJ statements is one way to use dynamic
SQL in your application. You can also use dynamic SQL directly through SQLJ
extensions provided by Oracle or through JDBC code within a SQLJ application.
See Also:
"Support for Dynamic SQL" and "SQLJ and JDBC Interoperability"
Note:
Remember that using PL/SQL in your SQLJ code would prevent portability to
other platforms, because PL/SQL is Oracle-specific.
5.3 Java Host, Context, and Result Expressions

This section discusses three categories of Java expressions used in SQLJ code: host
expressions, context expressions, and result expressions. Host expressions are the
most frequently used Java expressions. Another category of expressions, called meta
bind expressions, are used specifically for dynamic SQL operations and use syntax
similar to that of host expressions.
See Also:
"Support for Dynamic SQL"
SQLJ uses Java host expressions to pass arguments between Java code and
SQL operations. This is how you pass information between Java and SQL. Host
expressions are interspersed within the embedded SQL operations in the SQLJ source
code.
The most basic kind of host expression, consisting of only a Java identifier, is referred
to as a host variable. A context expression specifies a connection context instance
or execution context instance to be used for a SQLJ statement. A result expression
specifies an output variable for query results or a function return.
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• Overview of Host Expressions
• Basic Host Expression Syntax
• Examples of Host Expressions
• Overview of Result Expressions and Context Expressions
• Evaluation of Java Expressions at Run Time
• Examples of Evaluation of Java Expressions at Run Time (ISO Code Generation)
• Restrictions on Host Expressions
5.3.1 Overview of Host Expressions

Any valid Java expression can be used as a host expression. In the simplest case,
the expression consists of just a single Java variable. Other kinds of host expressions
include the following:
• Arithmetic expressions
• Java method calls with return values
• Java class field values
• Array elements
• Conditional expressions (a ? b : c)
• Logical expressions
• Bitwise expressions
Java identifiers used as host variables or in host expressions can represent any of the
following:
• Local variables
• Declared parameters
• Class fields
• Static or instance method calls
Local variables used in host expressions can be declared anywhere that other Java
variables can be declared. Fields can be inherited from a superclass.
Java variables that are legal in the Java scope where the SQLJ executable statement
appears can be used in a host expression in a SQL statement, presuming its type
is convertible to or from a SQL data type. Host expressions can be input, output, or
input-output.
See Also:
"Supported Types for Host Expressions"
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5.3.2 Basic Host Expression Syntax

A host expression is preceded by a colon (:). If the desired mode of the host
expression is not the default, then the colon must be followed by IN, OUT, or INOUT,
as appropriate, before the host expression itself. These are referred to as mode
specifiers. The default is OUT if the host expression is part of an INTO-list or is the
assignment expression in a SET statement. Otherwise, the default is IN. Any OUT or
INOUT host expression must be assignable.
Note:
When using the default, you can still include the mode specifier if desired.
The SQL code that surrounds a host expression can use any vendor-specific SQL
syntax. Therefore, no assumptions can be made about the syntax when parsing
the SQL operations and determining the host expressions. To avoid any possible
ambiguity, any host expression that is not a simple host variable (in other words, that is
more complex than a nondotted Java identifier) must be enclosed in parentheses.
To summarize the basic syntax:
• For a simple host variable without a mode specifier, put the host variable after the
colon, as in the following example:
:hostvar
• For a simple host variable with a mode specifier, put the mode specifier after the
colon and put white space (space, tab, newline, or comment) between the mode
specifier and the host variable, as in the following example:
:INOUT hostvar
The white space is required to distinguish between the mode specifier and the
variable name.
• For any other host expression, enclose the expression in parentheses and place it
after the mode specifier or after the colon, if there is no mode specifier, as in the
following examples:
:IN(hostvar1+hostvar2)
:(hostvar3*hostvar4)
:(index--)
White space is not required after the mode specifier in this example, because
the parenthesis is a suitable separator. However, a white space after the mode
specifier is allowed.
An outer set of parentheses is needed even if the expression already starts with a
begin-parenthesis, as in the following examples:
:((x+y).z)
:(((y)x).myOutput())
Syntax Notes
Keep the following in mind regarding the host expression syntax:
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• White space is always allowed after the colon as well as after the mode specifier.
Wherever white space is allowed, you can also have a comment.
You can have any of the following in the SQL namespace:
– SQL comments after the colon and before the mode specifier
– SQL comments after the colon and before the host expression if there is no
mode specifier
– SQL comments after the mode specifier and before the host expression
You can have the following in the Java namespace:
– Java comments within the host expression (inside the parentheses)
• The IN, OUT, and INOUT syntax used for host variables and expressions are not
case-sensitive. These tokens can be in uppercase, lowercase, or mixed.
• Do not confuse the IN, OUT, and INOUT syntax of SQLJ host expressions with
similar IN, OUT, and IN OUT syntax used in PL/SQL declarations to specify the
mode of parameters passed to PL/SQL stored functions and procedures.
Usage Notes
Keep the following in mind regarding the usage of host expressions:
• A simple host variable can appear multiple times in the same SQLJ statement, as
follows:
– If the host variable appears only as an input variable, then there are no
restrictions or complications.
– If at least one appearance of the host variable is as an output variable in
a PL/SQL block, then you will receive a portability warning if the translator
-warn=portability flag is set. SQLJ run-time behavior in this situation is
vendor-specific. Oracle SQLJ run time uses value semantics, as opposed to
reference semantics, for all occurrences of the host variable.
– If at least one appearance of the host variable is as an output variable in a
stored procedure call, stored function call, SET statement, or INTO-list, then
you will not receive any warning. SQLJ run-time behavior in this situation is
standardized, using value semantics.
Note:
The term output refers to OUT or INOUT variables, as applicable.
• If a host expression that is a simple host variable appears multiple times in a SQLJ
statement, then by default each appearance is treated completely independently
of the other appearances, using value semantics. However, if you use the SQLJ
translator -bind-by-identifier=true setting, then this is not the case. With a
true setting, multiple appearances of the same host variable in a given SQLJ
statement or PL/SQL block are treated as a single bind occurrence.
• When binding a string host expression into a WHERE clause for comparison against
CHAR data, be aware that there is a SQLJ option, -fixedchar, that accounts for
blank padding in the CHAR column when the comparison is made.
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5.3.3 Examples of Host Expressions

The following examples will help clarify the preceding syntax discussion.
Note:
Some of these examples use SELECT INTO statements, which are described
in "Single-Row Query Results: SELECT INTO Statements".
Example 1
In this example, two input host variables are used, one as a test value for a WHERE
clause and one to contain new data to be sent to the database.
Presume you have a database employee table emp with an ename column for employee
names and a sal column for employee salaries. The relevant Java code that defines
the host variables is as follows:
String empname = "SMITH";
double salary = 25000.0;
...
#sql { UPDATE emp SET sal = :salary WHERE ename = :empname };
IN is the default, but you can state it explicitly as well:

#sql { UPDATE emp SET sal = :IN salary WHERE ename = :IN empname };
As you can see, the colon (:) can immediately precede the variable when not using the
IN token, but :IN must be followed by white space before the host variable.
Example 2
This example uses an output host variable in a SELECT INTO statement, where you
want to find out the name of the employee whose employee number 28959.
String empname;
...
#sql { SELECT ename INTO :empname FROM emp WHERE empno = 28959 };
OUT is the default for an INTO-list, but you can state it explicitly as well:
#sql { SELECT ename INTO :OUT empname FROM emp WHERE empno = 28959 };
This statement looks in the empno column of the emp table for employee number 28959,
selects the name in the ename column of that row, and outputs it to the empname output
host variable, which is a Java String.
Example 3
This example uses an arithmetic expression as an input host expression. The Java
variables balance and minPmtRatio are multiplied, and the result is used to update the
minPayment column of the creditacct table for account number 537845.
float balance = 12500.0;
float minPmtRatio = 0.05;
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...
#sql { UPDATE creditacct SET minPayment = :(balance * minPmtRatio)
WHERE acctnum = 537845 };
Alternatively, to use the IN token:

#sql { UPDATE creditacct SET minPayment = :IN (balance * minPmtRatio)
WHERE acctnum = 537845 };
Example 4
This example shows the use of the output of a method call as an input host expression
and also uses an input host variable. This statement uses the value returned by
getNewSal() to update the sal column in the emp table for the employee who is
specified by the Java empname variable. Java code initializing the host variables is also
shown.
String empname = "SMITH";
double raise = 0.1;
...
#sql {UPDATE emp SET sal = :(getNewSal(raise, empname))
WHERE ename = :empname};
5.3.4 Overview of Result Expressions and Context Expressions

A context expression is an input expression that specifies the name of a connection
context instance or an execution context instance to be used in a SQLJ executable
statement. Any legal Java expression that yields such a name can be used.
A result expression is an output expression used for query results or a function return.
It can be any legal Java expression that is assignable, meaning that it can logically
appear on the left side of an equals sign. This is sometimes referred to as an l-value.
The following examples can be used for either result expressions or context
expressions:
• Local variables
• Declared parameters
• Class fields
• Array elements
Result expressions and context expressions appear lexically in the SQLJ space, unlike
host expressions, which appear lexically in the SQL space, that is, inside the curly
brackets of a SQLJ executable statement. Therefore, a result expression or context
expression must not be preceded by a colon.
5.3.5 Evaluation of Java Expressions at Run Time

This section discusses the evaluation of Java host expressions, connection context
expressions, execution context expressions, and result expressions when your
application executes.
Following is a simplified representation of a SQLJ executable statement that uses all
these kinds of expressions:
#sql [connctxt_exp, execctxt_exp] result_exp = { SQL with host expression };
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Java expressions can be used as any of the following, as appropriate:

• Connection context expression: Evaluated to specify the connection context
instance to be used
• Execution context expression: Evaluated to specify the execution context instance
to be used
• Result expression: To receive results, for example, from a stored function
• Host expression
For ISO standard code generation, the evaluation of Java expressions is well-defined,
even for the use of any side effects that depend on the order in which expressions are
evaluated.
For Oracle-specific code generation, evaluation of Java expressions follows the ISO
standard when there are no side effects, except when the -bind-by-identifier
option is enabled, but is implementation-specific and subject to change when there
are side effects.
Note:
The following discussion and the related examples later do not apply to
Oracle-specific code generation. If you use side effects as described here,
then request ISO code generation during translation.
The following is a summary, for ISO code, of the overall order of evaluation, execution,
and assignment of Java expressions for each statement that executes during run time.
1. If there is a connection context expression, then it is evaluated immediately, before
any other Java expressions are evaluated.
2. If there is an execution context expression, then it is evaluated after any
connection context expression, but before any result expression.
3. If there is a result expression, then it is evaluated after any context expressions,
but before any host expressions.
4. After evaluation of any context or result expressions, host expressions are
evaluated from left to right as they appear in the SQL operation. As each host
expression is encountered and evaluated, its value is saved to be passed to SQL.
Each host expression is evaluated once and only once.
5. IN and INOUT parameters are passed to SQL, and the SQL operation is executed.
6. After execution of the SQL operation, the output parameters, Java OUT and INOUT
host expressions, are assigned output in order from left to right as they appear in
the SQL operation.
Each output host expression is assigned once and only once.
7. The result expression, if there is one, is assigned output last.
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Note:
Host expressions inside a PL/SQL block are all evaluated together before
any statements within the block are executed. They are evaluated in the
order in which they appear, regardless of the control flow within the block.
Once the expressions in a statement have been evaluated, input and input-output
host expressions are passed to SQL, and then the SQL operation is executed.
After execution of the SQL operation, assignments are made to Java output host
expressions, input-output host expressions, and result expressions as follows:
1. OUT and INOUT host expressions are assigned output in order from left to right.
2. The result expression, if there is one, is assigned output last.
Note that during run time, all host expressions are treated as distinct values, even if
they share the same name or reference the same object. The execution of each SQL
operation is treated as if invoking a remote method, and each host expression is taken
as a distinct parameter. Each input or input-output parameter is evaluated and passed
as it is first encountered, before any output assignments are made for that statement,
and each output parameter is also taken as distinct and is assigned exactly once.
It is also important to remember that each host expression is evaluated only once.
An INOUT expression is evaluated when it is first encountered. When the output
assignment is made, the expression itself is not reevaluated nor are any side-effects
repeated.
5.3.6 Examples of Evaluation of Java Expressions at Run Time (ISO

Code Generation)
This section discusses, for ISO code generation, how Java expressions are evaluated
when your application executes.
Note:
Do not count on these effects if you use Oracle-specific code generation.
Request ISO code generation during translation if you depend on such
effects.
Evaluation of Prefix and Postfix Operators

When a Java expression contains a Java postfix increment or decrement operator,
the incrementing or decrementing occurs after the expression has been evaluated.
Similarly, when a Java expression contains a Java prefix increment or decrement
operator, the incrementing or decrementing occurs before the expression is evaluated.
This is equivalent to how these operators are handled in standard Java code.
The following is an example of postfix operator:
int indx = 1;
...
#sql { ... :OUT (array[indx]) ... :IN (indx++) ... };
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This example is evaluated as follows:

#sql { ... :OUT (array[1]) ... :IN (1) ... };
The indx variable is incremented to 2 and will have that value the next time it is
encountered, but not until after :IN (indx++) has been evaluated.
The following is the example of postfix operator:

int indx = 1;
...
#sql { ... :OUT (array[indx++]) ... :IN (indx++) ... };

#sql { ... :OUT (array[1]) ... :IN (2) ... };
The variable indx is incremented to 2 after the first expression is evaluated, but before
the second expression is evaluated. It is incremented to 3 after the second expression
is evaluated and will have that value the next time it is encountered.
The following example consists of both prefix and postfix operators:
int indx = 1;
...
#sql { ... :OUT (array[++indx]) ... :IN (indx++) ... };

#sql { ... :OUT (array[2]) ... :IN (2) ... };
The variable indx is incremented to 2 before the first expression is evaluated. It is

incremented to 3 after the second expression is evaluated and will have that value the
next time it is encountered.
Evaluation Order of IN, INOUT, and OUT Host Expressions

Host expressions are evaluated from left to right. Whether an expression is IN, INOUT,
or OUT makes no difference when it is evaluated. All that matters is its position in the
left-to-right order.
Consider the following example:
int[5] arry;
int n = 0;
...
#sql { SET :OUT (arry[n]) = :(++n) };

#sql { SET :OUT (arry[0]) = 1 };
One might expect input expressions to be evaluated before output expressions, but
that is not the case. The expression :OUT (arry[n]) is evaluated first because it is
the left-most expression. Then n is incremented prior to evaluation of ++n, because it is
being operated on by a prefix operator. Then ++n is evaluated as 1. The result will be
assigned to arry[0], not arry[1], because 0 was the value of n when it was originally
encountered.
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Expressions in PL/SQL Blocks Are Evaluated Before Statements Are Executed

Host expressions in a PL/SQL block are all evaluated in one sequence, before any
have been executed. Consider the following example:
int x=3;
int z=5;
...
#sql { BEGIN :OUT x := 10; :OUT z := :x; END };
System.out.println("x=" + x + ", z=" + z);

#sql { BEGIN :OUT x := 10; :OUT z := 3; END };
Therefore, it would print x=10, z=3.
All expressions in a PL/SQL block are evaluated before any are executed. In this
example, the host expressions in the second statement, :OUT z and :x, are evaluated
before the first statement is executed. In particular, the second statement is evaluated
while x still has its original value of 3, before it has been assigned the value 10.
Consider another example of how expressions are evaluated within a PL/SQL block:
int x=1, y=4, z=3;
...
#sql { BEGIN
:OUT x := :(y++) + 1;
:OUT z := :x;
END };

#sql { BEGIN
:OUT x := 4 + 1;
:OUT z := 1;
END };
The postfix increment operator is executed after :(y++) is evaluated, so the

expression is evaluated as 4, which is the initial value of y. The second
statement, :OUT z := :x, is evaluated before the first statement is executed.
Therefore, x still has its initialized value of 1. After execution of this block, x will have
the value 5 and z will have the value 1.
The following example demonstrates the difference between two statements appearing
in a PL/SQL block in one SQLJ executable statement, and the same statements
appearing in separate (consecutive) SQLJ executable statements.
First, consider the following, where two statements are in a PL/SQL block.
int y=1;
...
#sql { BEGIN :OUT y := :y + 1; :OUT x := :y + 1; END };

#sql { BEGIN :OUT y := 1 + 1; :OUT x := 1 + 1; END };
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The :y in the second statement is evaluated before either statement is executed.

Therefore, y has not yet received its output from the first statement. After execution of
this block, both x and y have the value 2.
Now, consider the situation where the same two statements are in PL/SQL blocks in
separate SQLJ executable statements.
int y=1;
#sql { BEGIN :OUT y := :y + 1; END };
#sql { BEGIN :OUT x := :y + 1; END };
The first statement is evaluated as follows:

#sql { BEGIN :OUT y := 1 + 1; END };
Then, it is executed and y is assigned the value 2.
After execution of the first statement, the second statement is evaluated as follows:
#sql { BEGIN :OUT x := 2 + 1; END };
This time, as opposed to the previous PL/SQL block example, y has already received
the value 2 from execution of the previous statement. Therefore, x is assigned the
value 3 after execution of the second statement.
Expressions in PL/SQL Blocks Are Always Evaluated Once Only

Each host expression is evaluated once, and only once, regardless of program flow
and logic.
Consider the following example of evaluation of host expression in a loop:
int count = 0;
...
#sql {
DECLARE
n NUMBER
BEGIN
n := 1;
WHILE n <= 100 LOOP
:IN (count++);
n := n + 1;
END LOOP;
END
};
The Java count variable will have the value 0 when it is passed to SQL, because it
is operated on by a postfix operator, as opposed to a prefix operator. It will then be
incremented to 1 and will hold that value throughout execution of this PL/SQL block.
It is evaluated only once as the SQLJ executable statement is parsed and then is
replaced by the value 1 prior to SQL execution.
Consider the following example that illustrates the evaluation of host expressions
in conditional blocks. This example demonstrates how each expression is always
evaluated, regardless of the program flow. As the block is executed, only one branch
of the IF...THEN...ELSE construct can be executed. However, before the block is
executed, all expressions in the block are evaluated in the order that the statements
appear.
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int x;
...
(operations on x)
...
#sql {
DECLARE
n NUMBER
BEGIN
n := :x;
IF n < 10 THEN
n := :(x++);
ELSE
n := :x * :x;
END LOOP;
END
};
Say the operations performed on x resulted in x having a value of 15. When the
PL/SQL block is executed, the ELSE branch will be executed and the IF branch will
not. However, all expressions in the PL/SQL block are evaluated before execution,
regardless of program logic or flow. Therefore, x++ is evaluated, then x is incremented,
and then each x is evaluated in the (x * x) expression. The IF...THEN...ELSE block
is evaluated as follows:
IF n < 10 THEN
n := 15;
ELSE
n := :16 * :16;
END LOOP;
After execution of this block, given an initial value of 15 for x, n will have the value 256.
Output Host Expressions Are Assigned Left to Right, Before Result Expression
Remember that OUT and INOUT host expressions are assigned in order from left to
right, and then the result expression, if any, is assigned last. If the same variable is
assigned more than once, then it will be overwritten according to this order, with the
last assignment taking precedence.
The following example contains multiple output host expressions referencing the same
variable:
#sql { CALL foo(:OUT x, :OUT x) };
If foo() outputs the values 2 and 3, respectively, then x will have the value 3 after the
SQLJ executable statement has finished executing. The right-hand assignment will be
performed last, thereby taking precedence.
The following example contains multiple output host expressions referencing the same
object:
MyClass x = new MyClass();
MyClass y = x;
...
#sql { ... :OUT (x.field):=1 ... :OUT (y.field):=2 ... };
After execution of the SQLJ executable statement, x.field will have a value of 2, and
not 1, because x is the same object as y, and field was assigned the value of 2 after
it was assigned the value of 1.
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The following example demonstrates the difference between having the output results
of a function assigned to a result expression and having the results assigned to an OUT
host expression. Consider the following function, with the invar input parameter, the
outvar output parameter, and a return value:
CREATE FUNCTION fn(invar NUMBER, outvar OUT NUMBER)
RETURN NUMBER AS BEGIN
outvar := invar + invar;
return (invar * invar);
END fn;
Now consider an example where the output of the function is assigned to a result
expression:
int x = 3;
#sql x = { VALUES(fn(:x, :OUT x)) };
The function will take 3 as the input, will calculate 6 as the output, and will return 9.
After execution, the :OUT x will be assigned first, giving x a value of 6. But finally the
result expression is assigned, giving x the return value of 9 and overwriting the value
of 6 previously assigned to x. So x will have the value 9 the next time it is encountered.
Now consider an example where the output of the function is assigned to an OUT host
variable instead of a result expression:
int x = 3;
#sql { BEGIN :OUT x := fn(:x, :OUT x); END };
In this case, there is no result expression and the OUT variables are simply assigned
left to right. After execution, the first :OUT x, on the left side of the equation, is
assigned first, giving x the function return value of 9. However, proceeding left to right,
the second :OUT x, on the right side of the equation, is assigned last, giving x the
output value of 6 and overwriting the value of 9 previously assigned to x. Therefore, x
will have the value 6 the next time it is encountered.
Note:
Some unlikely cases have been used in these examples to explain the
concepts of how host expressions are evaluated. In practice, it is not
advisable to use the same variable in both an OUT or INOUT host expression
or in an IN host expression inside a single statement or PL/SQL block. The
behavior in such cases is well defined in the Oracle SQLJ implementation,
but this practice is not covered in the SQLJ specification. Therefore, code
written in this manner will not be portable. Such code will generate a warning
from the SQLJ translator if the portable flag is set during semantics-
checking.
5.3.7 Restrictions on Host Expressions

Do not use in, out, and inout as identifiers in host expressions unless they are
enclosed in parentheses. Otherwise, they might be mistaken for mode specifiers. This
is not case-sensitive.
For example, you could use an input host variable called in, as follows:
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Single-Row Query Results: SELECT INTO Statements
:(in)
or:
:IN(in)
5.4 Single-Row Query Results: SELECT INTO Statements

When only a single row of data is being returned, SQLJ enables you to assign
selected items directly to Java host expressions inside SQL syntax. This is done using
the SELECT INTO statement. This section covers the following topics:
• SELECT INTO Syntax

• Examples of SELECT INTO Statements
• Examples with Host Expressions in SELECT-List
• SELECT INTO Error Conditions
5.4.1 SELECT INTO Syntax

The syntax for a SELECT INTO statement is as follows:
#sql { SELECT expression1,..., expressionN INTO :host_exp1,..., :host_expN
FROM table <optional_clauses> };
Keep in mind the following:

• The items expression1 through expressionN are expressions specifying what is
to be selected from the database. These can be any expressions valid for any
SELECT statement. This list of expressions is referred to as the SELECT-list. In a
simple case, these would be names of columns from a database table. It is also
legal to include a host expression in the SELECT-list.
• The items host_exp1 through host_expN are target host expressions, such as
variables or array elements. This list of host expressions is referred to as the
INTO-list.
• The item table is the name of the database table, view, or snapshot from which
you are selecting the data.
• The item optional_clauses is for any additional clauses you want to include that
are valid in a SELECT statement, such as a WHERE clause.
A SELECT INTO statement must return one, and only one, row of data, otherwise an
error will be generated at run time.
The default is OUT for a host expression in an INTO-list, but you can optionally state this
explicitly:
#sql { SELECT column_name1, column_name2 INTO :OUT host_exp1, :OUT host_exp2
FROM table WHERE condition };
Trying to use an IN or INOUT token in the INTO-list will result in an error at translation
time.
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Single-Row Query Results: SELECT INTO Statements
Note:
• Permissible syntax for expression1 through expressionN, the table,

and the optional clauses is the same as for any SQL SELECT statement.
• There can be any number of SELECT-list and INTO-list items, as long
as they match. That is, one INTO-list item per SELECT-list item, with
compatible types.
5.4.2 Examples of SELECT INTO Statements

The examples in this section use an employee table EMP with the following rows:
CREATE TABLE EMP (
EMPNO NUMBER(4),
ENAME VARCHAR2(10),
HIREDATE DATE );
The following is an example of a SELECT INTO statement with a single host expression
in the INTO-list:
String empname;
#sql { SELECT ename INTO :enpname FROM emp WHERE empno=28959 };
The following is an example of a SELECT INTO statement with multiple host

expressions in the INTO-list:
String empname;
Date hdate;
#sql { SELECT ename, hiredate INTO :empname, :hdate FROM emp
WHERE empno=28959 };
5.4.3 Examples with Host Expressions in SELECT-List

It is legal to use Java host expressions in the SELECT-list as well as in the INTO-list. For
example, you can select directly from one host expression into another, though this is
of limited usefulness, as follows:
...
#sql { SELECT :name1 INTO :name2 FROM emp WHERE empno=28959 };
...
More realistically, you may want to perform an operation or concatenation on the

data selected, as in the following examples. Assume Java variables were previously
declared and assigned, as necessary.
...
#sql { SELECT sal + :raise INTO :newsal FROM emp WHERE empno=28959 };
...
...
#sql { SELECT :(firstname + " ") || emp_last_name INTO :name FROM myemp
WHERE empno=28959 };
...
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Multirow Query Results: SQLJ Iterators
In the second example, presume myemp is a table much like the emp table but with
an emp_last_name column instead of an ename column. In the SELECT statement,
firstname is prepended to a single space (" "), using a Java host expression and the
Java string concatenation operator (+). This result is then passed to the SQL engine,
which uses SQL string concatenation operator (||) to append the last name.
5.4.4 SELECT INTO Error Conditions

Remember that SELECT INTO statements are intended for queries that return exactly
one row of data only. A SELECT INTO query that finds zero rows or multiple rows will
result in an exception, as follows:
• A SELECT INTO finding no rows will return an exception with a SQL state of 2000,
representing a "no data" condition.
• A SELECT INTO finding multiple rows will return an exception with a SQL state of
21000, representing a cardinality violation.
You can retrieve the SQL state through the getSQLState() method of the
java.sql.SQLException class.
This is vendor-independent behavior that is specified in the ISO SQLJ standard. There
is no vendor-specific error code in these cases. The error code is always 0.
5.5 Multirow Query Results: SQLJ Iterators

A large number of SQL operations are multirow queries. Processing multirow query
results in SQLJ requires a SQLJ iterator. A SQLJ iterator is a strongly typed version
of a JDBC result set and is associated with the underlying database cursor. SQLJ
iterators are primarily used to take query results from a SELECT statement.
Additionally, Oracle offers SQLJ extensions that enable you to use SQLJ iterators and
result sets in the following ways:
• As OUT host variables in executable SQL statements
• As INTO-list targets, such as in a SELECT INTO statement
• As a return type from a stored function call
• As column types in iterator declarations (essentially, nested iterators)
Note:
To use a SQLJ iterator in any of these ways, its class must be declared as
public. If you declared it at the class level or nested-class level, then it might
be advisable to declare it as public static.

• Iterator Concepts
• General Steps in Using an Iterator
• Named_ Positional_ and Result Set Iterators
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• Using Named Iterators

• Using Positional Iterators
• Using Iterators and Result Sets as Host Variables
• Using Iterators and Result Sets as Iterator Columns
See Also:
"Iterator Class Implementation and Advanced Functionality"
5.5.1 Iterator Concepts

Using a SQLJ iterator declaration results in a strongly typed iterator. This is the
typical usage for iterators and takes particular advantage of SQLJ semantics-checking
features during translation. It is also possible, and at times advantageous, to use
weakly typed iterators. There are generic classes you can instantiate in order to use a
weakly typed iterator.
• Overview of Strongly Typed Iterators
• Overview of Weakly Typed Iterators
5.5.1.1 Overview of Strongly Typed Iterators

Before using a strongly typed iterator object, you must declare an iterator class. An
iterator declaration specifies a Java class that SQLJ constructs for you, where the
class attributes define the type and, optionally, the name of the columns of data in the
iterator.
A SQLJ iterator object is an instance of such a specifically declared iterator class, with
a fixed number of columns of predefined type. This is as opposed to a JDBC result set
object, which is a standard java.sql.ResultSet instance and can, in principle, contain
any number of columns of any type.
When you declare an iterator, you specify either just the data type of the selected
columns, or both the data type and the name of the selected columns:
• Specifying the names and data types defines a named iterator class.
• Specifying just the data types defines a positional iterator class.
The data types and names, if applicable, that you declare determine how query results
will be stored in iterator objects you instantiate from that class. SQL data retrieved into
an iterator object are converted to the Java types specified in the iterator declaration.
When you query to populate a named iterator object, the name and data type of
the columns in the SELECT statement must match the name and data type of the
iterator columns. However, this is not case-sensitive. The order of the columns in
the SELECT statement is irrelevant. All that matters is that each column name in
the SELECT statement matches an iterator column name. In the simplest case, the
database column names directly match the iterator column names.
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For example, data from an ENAME column in a database table can be selected and
put into an iterator ename column. Alternatively, you can use an alias to map a
database column name to an iterator column name if the names differ. Also, in a
more complicated query, you can perform an operation between two columns and alias
the result to match the corresponding iterator column name.
Because SQLJ iterators are strongly typed, they offer the benefit of Java type-checking
during the SQLJ semantics-checking phase.
As an example, consider the following table:
CREATE TABLE EMPSAL (
EMPNO NUMBER(4),
ENAME VARCHAR2(10),
OLDSAL NUMBER(10),
RAISE NUMBER(10) );
Given this table, you can declare a named iterator as follows.

#sql iterator SalNamedIter (int empno, String ename, float raise);
Once declared, you can use this named iterator as follows:

class MyClass {
void func() throws SQLException {
...
SalNamedIter niter;
#sql niter = { SELECT ename, empno, raise FROM empsal };
... process niter ...

}
}
This is a simple case where the iterator column names match the table column names.
Note that the order of items in the SELECT statement does not matter when you use a
named iterator. Data is matched by name, not position.
When you query to populate a positional iterator object, the data is retrieved according
to the order in which you select the columns. Data from the first column selected from
the database table is placed into the first column of the iterator, and so on. The data
types of the table columns must be convertible to the types of the iterator columns,
but the names of the database columns are irrelevant, as the iterator columns have no
names.
Given the EMPSAL table, you can declare a positional iterator as follows:
#sql iterator SalPosIter (int, String, float);
You can use this positional iterator as follows:

class MyClass {
void func() throws SQLException {
...
SalPosIter piter;
#sql piter = { SELECT empno, ename, raise FROM empsal };
... process piter ...

}
}
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Note that the order of the data items in the SELECT statement must be the same as in
the iterator. The processing differs between named iterators and positional iterators.
General Iterator Notes

In addition to the preceding concepts, be aware of the following general notes about
iterators:
• The SELECT * syntax is allowed in populating an iterator, but is not recommended.
In the case of a positional iterator, this requires that the number of columns in the
table be equal to the number of columns in the iterator, and that the data types
match in order. In the case of a named iterator, this requires that the number of
columns in the table be greater than or equal to the number of columns in the
iterator and that the name and data type of each iterator column match a database
table column. However, if the number of columns in the table is greater, then a
warning will be generated unless the translator -warn=nostrict flag is set.
• Positional and named iterators are distinct and incompatible kinds of Java classes.
An iterator object of one kind cannot be cast to an iterator object of the other kind.
• Unlike a SQL cursor, an iterator instance is a first-class Java object. That is, it
can be passed and returned as a method parameter, for example. Also, an iterator
instance can be declared using Java class modifiers, such as public or private.
• SQLJ supports interoperability and conversion between SQLJ iterators and JDBC
result sets.
• Generally speaking, the contents of an iterator is determined only by the state
of the database at the time of execution of the SELECT statement that populated
it. Subsequent UPDATE, INSERT, DELETE, COMMIT, or ROLLBACK operations have no
effect on the iterator or its contents. The exception to this is if you declare an
iterator to be scrollable and sensitive to changes in the data.
5.5.1.2 Overview of Weakly Typed Iterators

In case you do not want to declare an iterator class, the Oracle SQLJ implementation
enables you to use a weakly typed iterator. Such iterators are known as result
set iterators. To use a plain, that is, nonscrollable result set iterator, instantiate
the sqlj.runtime.ResultSetIterator class. To use a scrollable result set iterator,
instantiate the sqlj.runtime.ScrollableResultSetIterator class.
The drawback to using result set iterators, compared to strongly typed iterators, is that
SQLJ cannot perform as much semantics-checking for your queries.
5.5.2 General Steps in Using an Iterator

You must follow the following general steps to use SQLJ named or positional iterator:
1. Use a SQLJ declaration to define the iterator class (in other words, to define the
iterator type).
2. Declare a variable of the iterator class.
3. Populate the iterator variable with the results from a SQL query, using a SELECT
statement.
4. Access the query columns in the iterator. How to accomplish this differs between
named iterators and positional iterators.
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5. When you finish processing the results of the query, close the iterator to release its
resources.
5.5.3 Named, Positional, and Result Set Iterators

There are advantages and appropriate situations for each kind of SQLJ iterator.
Named iterators enable greater flexibility. Because data selection into a named iterator
matches the columns in the SELECT statement to iterator columns by name, you need
not be concerned about the order in your query. This is less prone to error, as it is not
possible for data to be placed into the wrong column. If the names do not match, then
the SQLJ translator will generate an error when it checks the SQL statements against
the database.
Positional iterators offer a familiar paradigm and syntax to developers who have
experience with other embedded-SQL languages. With named iterators you use a
next() method to retrieve data, while with positional iterators you use FETCH INTO
syntax similar to that of Pro*C, for example. Each fetch implicitly advances to the next
available row of the iterator before retrieving the next set of values.
However, positional iterators do offer less flexibility than named iterators, because you
are selecting data into iterator columns by position, instead of by name. You must be
certain of the order of items in your SELECT statement. Also, you must select data into
all columns of the iterator. It is possible to have data written into the wrong iterator
column, if the data type of that column happens to match the data type of the table
column being selected.
Access to individual data elements is also less convenient with positional iterators.
Named iterators, because they store data by name, are able to have convenient
accessor methods for each column. For example, there would be an ename() method
to retrieve data from an ename iterator column. With positional iterators, you must fetch
data directly into Java host expressions with the FETCH INTO statement, and the host
expressions must be in the correct order.
If you do not want to declare strongly typed iterator classes for your queries, then
you can choose the alternative of using weakly typed result set iterators. Result
set iterators are most convenient when converting JDBC code to SQLJ code. You
must balance this consideration against the fact that result set iterators, either
ResultSetIterator instances or ScrollableResultSetIterator instances, do not
allow complete SQLJ semantics-checking during translation. With named or positional
iterators, SQLJ verifies that the data types of columns in the SELECT statement match
the Java types into which the data will be materialized. With result set iterators, this is
not possible.
Comparative Iterator Notes

Be aware of the following notes regarding SQLJ iterators:
• In populating a positional iterator, the number of columns you select from the
database must equal the number of columns in the iterator. In populating a named
iterator, the number of columns you select from the database can never be less
than the number of columns in the iterator, but can be greater than the number
of columns in the iterator if you have the translator -warn=nostrict flag set.
Unmatched columns are ignored in this case.
• Although the term "fetching" often refers to fetching data from a database,
remember that a FETCH INTO statement for a positional iterator does not
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necessarily involve a round trip to the server. This depends on the row-prefetch
value. This is because you are fetching data from the iterator, and not the
database. However, if the row-prefetch value is 1, then each fetch does involve
a separate trip to the database. The row-prefetch value determines how many
rows are retrieved with each trip to the database.
• Result set iterators use the same FETCH INTO syntax that is used with positional
iterators and are subject to the same restriction at run time. That is, the number of
data items in the SELECT-list must match the number of variables that are assigned
data in the FETCH statement.
5.5.4 Using Named Iterators

When you declare a named iterator class, you declare the name as well as the data
type of each column of the iterator. When you select data into a named iterator, the
columns in the SELECT statement must match the iterator columns in two ways:
• The name of each data item in the SELECT statement, either a table column
name or an alias, must match an iterator column name. However, this is not
case-sensitive. That is, ename or Ename would match ENAME).
• The data type of each iterator column must be compatible with the data type of the
corresponding data item in the SELECT statement according to standard JDBC type
mappings.
The order in which attributes are declared in the named iterator class declaration is
irrelevant. Data is selected into the iterator based on name alone.
A named iterator has a next() method to retrieve data row by row and an accessor
method for each column to retrieve the individual data items. The accessor method
names are identical to the column names. Unlike most accessor method names in
Java, accessor method names in named iterator classes do not start with get. For
example, a named iterator object with a column sal would have a sal() accessor
method.
Note:
The following restrictions apply in naming the columns of a named iterator:
• Column names cannot use Java reserved words.
• Column names cannot have the same name as utility methods
provided in named iterator classes, such as the next(), close(),
getResultSet(), and isClosed() methods. For scrollable named
iterators, this includes additional methods such as previous(), first(),
and last().
Declaring Named Iterator Classes

Use the following syntax to declare a named iterator class:
#sql <modifiers> iterator classname <implements clause> <with clause>
( type-name-list );
In this syntax, modifiers is an optional sequence of legal Java class modifiers,

classname is the desired class name for the iterator, and type-name-list is a list
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of the Java types and names equivalent to or compatible with the column types and
column names in a database table.
The implements clause and with clause are optional, specifying interfaces to
implement and variables to define and initialize, respectively.
See Also:
"Declaration IMPLEMENTS Clause" and "Declaration WITH Clause"
Consider the following table:

CREATE TABLE PROJECTS (
ID NUMBER(4),
PROJNAME VARCHAR(30),
START_DATE DATE,
DURATION NUMBER(3) );
You can declare the following named iterator to use with this table:
#sql public iterator ProjIter (String projname, int id, Date deadline);
This will result in an iterator class with columns of data accessible, using the following
provided accessor methods: projname(), id(), and deadline().
Note:
following ways:
• Declare it at class-level scope or nested-class-level scope, with public
static modifiers.
Instantiating and Populating Named Iterators

Continuing to use the PROJECTS table and ProjIter iterator defined in the preceding
section, note that there are columns in the table whose names and data types match
the id and projname columns of the iterator. However, you must use an alias and
perform an operation to populate the deadline column of the iterator. Following is an
example:
ProjIter projsIter;
#sql projsIter = { SELECT start_date + duration AS deadline, projname, id

FROM projects WHERE start_date + duration >= sysdate };
This calculates a deadline for each project by adding its duration to its start date, then
aliases the results as deadline to match the deadline iterator column. It also uses a
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WHERE clause so that only future deadlines are processed, that is, deadlines beyond
the current system date in the database.
Similarly, you must create an alias if you want to use a function call. Suppose you have
a MAXIMUM() function that takes a DURATION entry and an integer as input and returns
the maximum of the two. For example, you could input the value 3 to ensure that each
project has at least a three-month duration in your application.
Now, presume you are declaring your iterator as follows:
#sql public iterator ProjIter2 (String projname, int id, float duration);
You could use the MAXIMUM() function in your query, with an alias for the result, as
follows:
ProjIter2 projsIter2;
#sql projsIter2 = { SELECT id, projname, maximum(duration, 3) AS duration

FROM projects };
Generally, you must use an alias in your query for any data item in the SELECT
statement whose name is not a legal Java identifier or does not match a column name
in the iterator.
Remember that in populating a named iterator, the number of columns you select
from the database can never be less than the number of columns in the iterator.
The number of columns you select can be greater than the number of columns in
the iterator, because unmatched columns are ignored. However, this will generate a
warning, unless you have the SQLJ -warn=nostrict option set.
Accessing Named Iterators

Use the next() method of the named iterator object to step through the data that
was selected into it. To access each column of each row, use the accessor methods
generated by SQLJ, typically inside a while loop.
Whenever next() is called:
• If there is another row to retrieve from the iterator, then next() retrieves the row
and returns true.
• If there are no more rows to retrieve, next() returns false.
The following is an example of how to access the data of a named iterator, repeating
the declaration, instantiation, and population code illustrated in the preceding section.
Note:
Each iterator has a close() method that you must always call when you
finish retrieving data from the iterator. This is necessary to close the iterator
and free its resources.
Presume the following iterator class declaration:

#sql public iterator ProjIter (String projname, int id, Date deadline);
Populate and then access an instance of this iterator class as follows:
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// Declare the iterator variable

ProjIter projsIter;
// Instantiate and populate iterator; order of SELECT doesn't matter

#sql projsIter = { SELECT start_date + duration AS deadline, projname, id
FROM projects WHERE start_date + duration >= sysdate };
// Process the results

while (projsIter.next()) {
System.out.println("Project name is " + projsIter.projname());
System.out.println("Project ID is " + projsIter.id());
System.out.println("Project deadline is " + projsIter.deadline());
}
// Close the iterator

projsIter.close();
...
Note the convenient use of the projname(), id(), and deadline() accessor methods
to retrieve the data. Note also that the order of the SELECT items does not matter, nor
does the order in which the accessor methods are used.
However, remember that accessor method names are created with the case exactly as
in your declaration of the iterator class. The following will generate compilation errors.
Consider the following declaration of the iterator:
#sql iterator Cursor1 (String NAME);
The code for using the iterator is as follows:

...
Cursor1 c1;
#sql c1 = { SELECT NAME FROM TABLE };
while (c1.next()) {
System.out.println("The name is " + c1.name());
}
...
The Cursor1 class has a method called NAME(), and not name(). You will have to use
c1.NAME() in the System.out.println statement.
5.5.5 Using Positional Iterators

When you declare a positional iterator class, you declare the data type of each column
but not the column name. The Java types into which the columns of the SQL query
results are selected must be compatible with the data types of the SQL data. The
names of the database columns or data items in the SELECT statement are irrelevant.
Because names are not used, the order in which you declare your positional iterator
Java types must exactly match the order in which the data is selected.
To retrieve data from a positional iterator once data has been selected into it, use a
FETCH INTO statement followed by an endFetch() method call to determine if you have
reached the end of the data.
Declaring Positional Iterator Classes

Use the following syntax to declare a positional iterator class:
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#sql <modifiers> iterator classname <implements clause> <with clause>

( position-list );
In this syntax, modifiers is an optional sequence of legal Java class modifiers and the
position-list is a list of Java types compatible with the column types in a database
table.
The implements clause and with clause are optional, specifying interfaces to
See Also:
Now consider an employee table EMP with the following rows:

CREATE TABLE EMP (
EMPNO NUMBER(4),
ENAME VARCHAR2(10),
SAL NUMBER(7,2) );
And consider the following positional iterator declaration:

#sql public iterator EmpIter (String, int, float);
This example defines the EmpIter Java class with unnamed String, int, and float
columns. Note that the table columns and iterator columns are in a different order, with
the String corresponding to ENAME and the int corresponding to EMPNO. The order of
the iterator columns determines the order in which you must select the data.
Note:
following ways:
• Declare it at class-level scope or nested-class-level scope, with public
static modifiers.
Instantiating and Populating Positional Iterators

Instantiating and populating a positional iterator is no different than doing so for a
named iterator, except that you must be certain that the data items in the SELECT
statement are in the proper order.
The three data types in the EmpIter iterator class are compatible with the types of the
EMP table, but be careful how you select the data, because the order is different. The
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following will work, because the data items in the SELECT statement are in the same
order as the iterator columns:
EmpIter empsIter;
#sql empsIter = { SELECT ename, empno, sal FROM emp };
Remember that in populating a positional iterator, the number of columns you select
from the database must equal the number of columns in the iterator.
Accessing Positional Iterators

Access the columns defined by a positional iterator using SQL FETCH INTO syntax.
The INTO part of the command specifies Java host variables that receive the results
columns. The host variables must be in the same order as the corresponding iterator
columns. Use the endFetch() method provided with all positional iterator classes to
determine whether the last fetch reached the end of the data.
Note:
• The endFetch() method initially returns true before any rows have
been fetched, then returns false once a row has been successfully
retrieved, and then returns true again when a FETCH finds no more rows
to retrieve. Therefore, you must perform the endFetch() test after the
FETCH INTO statement. If your endFetch() test precedes the FETCH INTO
statement, then you will never retrieve any rows, because endFetch()
would be true before your first FETCH and you would immediately break
out of the while loop.
• The endFetch() test must be before the results are processed, however,
because the FETCH does not throw a SQL exception when it reaches the
end of the data, it just triggers the next endFetch() call to return true. If
there is no endFetch() test before results are processed, then your code
will try to process NULL or invalid data from the first FETCH attempt after
the end of the data had been reached.
• Each iterator has a close() method that you must always call once you
finish retrieving data from it. This is necessary to close the iterator and
free its resources.
The following is an example, repeating the declaration, instantiation, and population

code illustrated in the preceding section. Note that the Java host variables in the
SELECT statement are in the same order as the columns of the positional iterator, which
is mandatory.
First, presume the following iterator class declaration:
#sql public iterator EmpIter (String, int, float);
Populate and then access an instance of this iterator class as follows:

// Declare and initialize host variables
int empnum=0;
String empname=null;
float salary=0.0f;
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// Declare an iterator instance

EmpIter empsIter;
#sql empsIter = { SELECT first_name, employee_id, salary FROM employees };
while (true) {
#sql { FETCH :empsIter INTO :empnum, :empname, :salary };
if (empsIter.endFetch()) break; // This test must be AFTER fetch,
// but before results are processed.
System.out.println("Name is " + empname);
System.out.println("Employee number is " + empnum);
System.out.println("Salary is " + salary);
}
// Close the iterator

empsIter.close();
...
The empname, empnum, and salary variables are Java host variables whose types must
match the types of the iterator columns.
Do not use the next() method for a positional iterator. A FETCH operation calls it
implicitly to move to the next row.
Note:
Host variables in a FETCH INTO statement must always be initialized because
they are assigned in one branch of a conditional statement. Otherwise, you
will get a compiler error indicating they may never be assigned. FETCH can
assign the variables only if there was a row to be fetched.
Positional Iterator Navigation with the next() Method

The positional iterator FETCH clause discussed in the preceding section performs a
movement, an implicit next() call, before it populates the host variables, if any. As
an alternative, the Oracle SQLJ implementation supports a special FETCH syntax in
conjunction with explicit next() calls in order to use the same movement logic as
with JDBC result sets and SQLJ named iterators. Using this special FETCH syntax, the
semantics differ. There is no implicit next() call before the INTO-list is populated.
5.5.6 Using Iterators and Result Sets as Host Variables

SQLJ supports SQLJ iterators and JDBC result sets as host variables. Using iterators
and result sets is fundamentally the same, with differences in declarations and in
accessor methods to retrieve the data.
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Chapter 5
Note:
• Additionally, SQLJ supports iterators and result sets as return variables

for stored functions.
• Oracle JDBC drivers currently do not support result sets as
input host variables. There is a setCursor() method in the
OraclePreparedStatement class, but it raises an exception at run time, if
called.
For the examples in this section, consider the following department and employee
tables:
CREATE TABLE DEPT (
DEPTNO NUMBER(2),
DNAME VARCHAR2(14) );
CREATE TABLE EMP (

EMPNO NUMBER(4),
ENAME VARCHAR2(10),
SAL NUMBER(7,2),
DEPTNO NUMBER(2) );
Example: Use of Result Set as OUT Host Variable

This example uses a JDBC result set as an output host variable.
...
ResultSet rs;
...
#sql { BEGIN
OPEN :OUT rs FOR SELECT ename, empno FROM emp;
END };
while (rs.next())
{
String empname = rs.getString(1);
int empnum = rs.getInt(2);
}
rs.close();
...
This example opens the result set rs in a PL/SQL block to receive data from a SELECT
statement, selects data from the ENAME and EMPNO columns of the EMP table, and then
loops through the result set to retrieve data into local variables.
Example: Use of Iterator as OUT Host Variable

This example uses a named iterator as an output host variable.
The iterator can be declared as follows:
#sql public <static> iterator EmpIter (String ename, int empno);
The public modifier is required, and the static modifier may be advisable if your
declaration is at class level or nested-class level.
This iterator can be used as follows:
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Chapter 5
...
EmpIter iter;
...
#sql { BEGIN
OPEN :OUT iter FOR SELECT ename, empno FROM emp;
END };
while (iter.next())
{
String empname = iter.ename();
int empnum = iter.empno();
...process/output empname and empnum...

}
iter.close();
...
This example opens the iterator iter in a PL/SQL block to receive data from a SELECT
statement, selects data from the ENAME and EMPNO columns of the EMP table, and then
loops through the iterator to retrieve data into local variables.
Example: Use of Iterator as OUT Host Variable for SELECT INTO

This example uses a named iterator as an output host variable, taking data through a
SELECT INTO statement. OUT is the default for host variables in an INTO-list.

#sql public <static> iterator ENameIter (String ename);
This iterator can be used as follows:
...
ENameIter enamesIter;
String deptname;
...
#sql { SELECT dname, cursor

(SELECT ename FROM emp WHERE deptno = dept.deptno)
INTO :deptname, :enamesIter FROM dept WHERE deptno = 20 };
System.out.println(deptname);
while (enamesIter.next())
{
System.out.println(enamesIter.ename());
}
enamesIter.close();
...
This example uses nested SELECT statements to accomplish the following:
• Select the name of department number 20 from the DEPT table, selecting it into the
deptname output host variable.
• Query the EMP table to select all employees whose department number is 20,
selecting the resulting cursor into the enamesIter output host variable, which is a
named iterator.
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• Print the department name.

• Loop through the named iterator printing employee names. This prints the names
of all employees in the department.
In most cases, using SELECT INTO is more convenient than using nested iterators
if you are retrieving a single row in the outer SELECT, although that option is also
available. Also, with nested iterators, you would have to process the data to determine
how many rows there are in the outer SELECT. With SELECT INTO you are assured of
just one row.
5.5.7 Using Iterators and Result Sets as Iterator Columns

The Oracle SQLJ implementation includes extensions that allow iterator declarations
to specify columns of ResultSet type or columns of other iterator types declared within
the current scope. In other words, iterators and result sets can exist within iterators.
These column types are used to retrieve a column in the form of a cursor. This is
useful for nested SELECT statements that return nested table information.
The following examples are functionally identical. Each uses a nested result set or
iterator, that is, result sets or iterators in a column within an iterator, to print all the
employees in each department in the DEPT table. The first example uses result sets
within a named iterator, the second example uses named iterators within a named
iterator, and the third example uses named iterators within a positional iterator.
Following are the steps:
1. Select each department name (DNAME) from the DEPT table.
2. Do a nested SELECT into a cursor to get all employees from the EMP table for each
department.
3. Put the department names and sets of employees into the outer iterator (iter),
which has a name column and an iterator column. The cursor with the employee
information for any given department goes into the iterator column of the row of
the outer iterator corresponding to the department.
4. Go through a nested loop that, for each department, prints the department name
and then loops through the inner iterator to print all employee names for that
department.
Example 5-1 Example: Result Set Column in a Named Iterator
This example uses a column of type ResultSet in a named iterator.

#sql iterator DeptIter (String dname, ResultSet emps);
The code that uses the iterator is as follows:

...
DeptIter iter;
...
#sql iter = { SELECT dname, cursor
AS emps FROM dept };
while (iter.next())
{
System.out.println(iter.dname());
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ResultSet enamesRs = iter.emps();

while (enamesRs.next())
{
String empname = enamesRs.getString(1);
System.out.println(empname);
}
enamesRs.close();
}
iter.close();
...
Example 5-2 Example: Named Iterator Column in a Named Iterator

This example uses a named iterator that has a column whose type is that of a
previously defined named iterator (nested iterators).
The iterator declaration is as follows:
#sql iterator ENameIter (String ename);
#sql iterator DeptIter (String dname, ENameIter emps);
The code that uses this iterator is as follows:

...
DeptIter iter;
...
AS emps FROM dept };
while (iter.next())
{
System.out.println(iter.dname());
ENameIter enamesIter = iter.emps();
{
}
enamesIter.close();
}
iter.close();
...
Example 5-3 Example: Named Iterator Column in a Positional Iterator

This example uses a positional iterator that has a column whose type is that of a
previously defined named iterator (nested iterators). This uses the FETCH INTO syntax
of positional iterators. This example is functionally equivalent to the previous two.
Note that because the outer iterator is a positional iterator, there does not have to
be an alias to match a column name, as was required when the outer iterator was a
named iterator in the previous example.
The iterator declaration is as follows:
#sql iterator ENameIter (String ename);
#sql iterator DeptIter (String, ENameIter);
The code that uses this iterator is as follows:

...
DeptIter iter;
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Chapter 5
Assignment Statements (SET)
...
FROM dept };
while (true)
{
String dname = null;
ENameIter enamesIter = null;
#sql { FETCH :iter INTO :dname, :enamesIter };
if (iter.endFetch()) break;
System.out.println(dname);
{
}
enamesIter.close();
}
iter.close();
...
5.6 Assignment Statements (SET)

SQLJ enables you to assign a value to a Java host expression inside a SQL operation.
This is known as an assignment statement and is accomplished using the following
syntax:
#sql { SET :host_exp = expression };
The host_exp is the target host expression, such as a variable or array index. The
expression could be a number, host expression, arithmetic expression, function call,
or other construct that yields a valid result into the target host expression.
The default is OUT for a target host expression in an assignment statement, but you
can optionally state this explicitly:
#sql { SET :OUT host_exp = expression };
Trying to use an IN or INOUT token in an assignment statement will result in an error at

translation time.
The preceding statements are functionally equivalent to the following PL/SQL code:
#sql { BEGIN :OUT host_exp := expression; END };
Here is a simple example of an assignment statement:

#sql { SET :x = foo1() + foo2() };
This statement assigns to x the sum of the return values of foo1() and foo2() and
assumes that the type of x is compatible with the type of the sum of the outputs of
these functions.
Consider the following additional examples:
int i2;
java.sql.Date dat;
...
#sql { SET :i2 = TO_NUMBER(substr('750 etc.', 1, 3)) +
TO_NUMBER(substr('250 etc.', 1, 3)) };
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Stored Procedure and Function Calls
...
#sql { SET :dat = sysdate };
...
The first statement will assign to i2 the value 1000. The substr() calls takes the first
three characters of the strings, that is, "750" and "250". The TO_NUMBER() calls convert
the strings to the numbers 750 and 250.
The second statement will read the database system date and assign it to dat.
An assignment statement is especially useful when you are performing operations

on return variables from functions stored in the database. You do not need an
assignment statement to simply assign a function result to a variable, because you
can accomplish this using standard function call syntax. You also do not need an
assignment statement to manipulate output from Java functions, because you can
accomplish that in a typical Java statement. So you can presume that foo1() and
foo2() are stored functions in the database, not Java functions.
5.7 Stored Procedure and Function Calls

SQLJ provides convenient syntax for calling stored procedures and stored functions in
the database. These procedures and functions could be written in Java, PL/SQL, or
any other language supported by the database.
A stored function requires a result expression in your SQLJ executable statement
to accept the return value and, optionally, can take input, output, or input-output
parameters as well.
A stored procedure does not have a return value. Optionally, it can take input, output,
or input-output parameters. A stored procedure can return output through any output
or input-output parameter.
• Calling Stored Procedures
• Calling Stored Functions
• Using Iterators and Result Sets as Stored Function Returns
5.7.1 Calling Stored Procedures

Stored procedures do not have a return value but can take a list with input, output, and
input-output parameters. Stored procedure calls use the CALL token. The CALL token is
followed by white space and then the procedure name. There must be a space after
the CALL token to differentiate it from the procedure name. There cannot be a set of
outer parentheses around the procedure call. This differs from the syntax for function
calls. The syntax for the CALL token is as follows:
#sql { CALL PROC(<PARAM_LIST>) };
PROC is the name of the stored procedure, which can optionally take a list of input,
output, and input-output parameters. PROC can include a schema or package name as
well, such as HR.MYPROC().
Presume that you have defined the following PL/SQL stored procedure:
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CREATE OR REPLACE PROCEDURE MAX_DEADLINE (deadline OUT DATE) IS

BEGIN
SELECT MAX(start_date + duration) INTO deadline FROM projects;
END;
This reads the PROJECTS table, looks at the START_DATE and DURATION columns,
calculates start_date + duration in each row, then takes the maximum START_DATE
+ DURATION total, and assigns it to DEADLINE, which is an output parameter of type
DATE.
In SQLJ, you can call this MAX_DEADLINE procedure as follows:

java.sql.Date maxDeadline;
...
#sql { CALL MAX_DEADLINE(:out maxDeadline) };
For any parameters, you must use the host expression tokens IN, OUT, and INOUT
appropriately, to match the input, output, and input-output designations of the stored
procedure. Additionally, the types of the host variables you use in the parameter list
must be compatible with the parameter types of the stored procedure.
Note:
If you want your application to be compatible with Oracle7 Database, then do
not include empty parentheses for the parameter list if the procedure takes
no parameters. For example:
#sql { CALL MAX_DEADLINE };
not:
#sql { CALL MAX_DEADLINE() };
5.7.2 Calling Stored Functions

Stored functions have a return value and can also take a list of input, output, and
input-output parameters. Stored function calls use the VALUES token. The VALUES token
is followed by the function call. In standard SQLJ, the function call must be enclosed in
a set of outer parentheses. In the Oracle SQLJ implementation, the outer parentheses
are optional. When using the outer parentheses, it does not matter if there is white
space between the VALUES token and the begin-parenthesis. The syntax for the VALUES
token is as follows:
#sql result = { VALUES(FUNC(PARAM_LIST)) };
In this syntax, result is the result expression, which takes the function return value.
FUNC is the name of the stored function, which can optionally take a list of input, output,
and input-output parameters. FUNC can include a schema or package name, such as
HR.MYFUNC().
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Note:
A VALUES token can also be used in INSERT INTO table VALUES syntax
supported by the Oracle SQL implementation, but these situations are
unrelated semantically and syntactically.
Referring back to the example in "Calling Stored Procedures", consider defining the
stored procedure as a stored function instead, as follows:
CREATE OR REPLACE FUNCTION GET_MAX_DEADLINE RETURN DATE IS
deadline DATE;
BEGIN
SELECT MAX(start_date + duration) INTO deadline FROM projects;
RETURN deadline;
END;
In SQLJ, you can call this GET_MAX_DEADLINE function as follows:

java.sql.Date maxDeadline;
...
#sql maxDeadline = { VALUES(GET_MAX_DEADLINE) };
The result expression must have a type compatible with the return type of the function.
In the Oracle SQLJ implementation, the following syntax is also allowed:
#sql maxDeadline = { VALUES GET_MAX_DEADLINE };
Note that the outer parentheses is omitted.

For stored function calls, as with stored procedures, you must use the host expression
tokens IN, OUT, and INOUT appropriately, to match the input, output, and input-output
parameters of the stored function. Additionally, the types of the host variables you
use in the parameter list must be compatible with the parameter types of the stored
function.
Note:
If you want your stored function to be portable to non-Oracle environments,
then you should use only input parameters in the calling sequence, not
output or input-output parameters.
5.7.3 Using Iterators and Result Sets as Stored Function Returns

SQLJ supports assigning the return value of a stored function to an iterator or result
set variable, if the function returns a REF CURSOR type.
The following example uses an iterator to take a stored function return. Using a result
set is similar.
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Example: Iterator as Stored Function Return

This example uses an iterator as a return type for a stored function, using a REF
CURSOR type in the process.
Presume the following function definition:

CREATE OR REPLACE PACKAGE sqlj_refcursor AS
TYPE EMP_CURTYPE IS REF CURSOR;
FUNCTION job_listing (j varchar2) RETURN EMP_CURTYPE;
END sqlj_refcursor;
CREATE OR REPLACE PACKAGE BODY sqlj_refcursor AS

FUNCTION job_listing (j varchar) RETURN EMP_CURTYPE IS
DECLARE
rc EMP_CURTYPE;
BEGIN
OPEN rc FOR SELECT ename, empno FROM emp WHERE job = j;
RETURN rc;
END;
END sqlj_refcursor;
Declare the iterator as follows:

#sql public <static> iterator EmpIter (String ename, int empno);
The code that uses the iterator and the function is as follows:
EmpIter iter;
...
#sql iter = { VALUES(sqlj_refcursor.job_listing('SALES')) };
while (iter.next())
{
String empname = iter.ename();
int empnum = iter.empno();
... process empname and empnum ...

}
iter.close();
...
This example calls the job_listing() function to return an iterator that contains the
name and employee number of each employee whose job title is SALES. It then
retrieves this data from the iterator.
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6
Type Support
This chapter documents data types supported by the Oracle SQLJ implementation,
listing supported SQL types and the Java types that correspond to them. This is
followed by details about support for streams and Oracle type extensions. SQLJ
support of Java types refers to types that can be used in host expressions.
This chapter covers the following topics:
• Supported Types for Host Expressions
• Support for Streams
• Support for JDBC 2.0 LOB Types and Oracle Type Extensions
See Also:
Objects_ Collections_ and OPAQUE Types
6.1 Supported Types for Host Expressions

This section summarizes the types supported by the Oracle SQLJ implementation,
including information about new support for Java Database Connectivity (JDBC) 2.0
types.
See Also:
Oracle Database JDBC Developer's Guide for a complete list of legal Java
mappings for each Oracle SQL type
Note:
SQLJ performs implicit conversions between SQL and Java types. Although
this is generally useful and helpful, it can produce unexpected results. Do
not rely on translation-time type-checking alone to ensure the correctness of
your code.

• Summary of Supported Types
• Supported Types and Requirements for JDBC 2.0
• Using PL/SQL BOOLEAN_ RECORD Types_ and TABLE Types
6-1
Chapter 6
Supported Types for Host Expressions
6.1.1 Summary of Supported Types

Table 6–1 lists the Java types that you can use in host expressions when employing
Oracle JDBC drivers. This table also documents the correlation between Java types,
SQL types whose type codes are defined in the oracle.jdbc.OracleTypes class, and
data types in Oracle Database 12c Release 2 (12.2).
Note:
The OracleTypes class simply defines a type code, which is an integer
constant, for each Oracle data type. For standard JDBC types, the
OracleTypes value is identical to the standard java.sql.Types value.
SQL data output to a Java variable is converted to the corresponding Java type. A
Java variable input to SQL is converted to the corresponding Oracle data type.
Table 6-1 Type Mappings for Supported Host Expression Types
Java Type OracleTypes Definition Oracle SQL Data Type

STANDARD JDBC 1.x TYPES
boolean BIT NUMBER
byte TINYINT NUMBER
short SMALLINT NUMBER
int INTEGER NUMBER
long BIGINT NUMBER
float REAL NUMBER
double FLOAT, DOUBLE NUMBER
java.lang.String CHAR VARCHAR CHAR VARCHAR2 LONG
LONGVARCHAR
byte[] BINARY VARBINARY RAW RAW LONGRAW
LONGVARBINARY
java.sql.Date DATE DATE
java.sql.Time TIME DATE
java.sql.Timestamp TIMESTAMP TIMESTAMP DATE TIMESTAMP
java.math.BigDecimal NUMERIC DECIMAL NUMBER NUMBER
STANDARD JDBC 2.0 TYPES
java.sql.Blob BLOB BLOB
java.sql.Clob CLOB CLOB
java.sql.Struct STRUCT Object types
java.sql.Ref REF Reference types
java.sql.Array ARRAY Collection types
Custom object classes implementing STRUCT Object types
java.sql.SQLData
6-2
Chapter 6
Table 6-1 (Cont.) Type Mappings for Supported Host Expression Types

JAVA WRAPPER CLASSES
java.lang.Boolean BIT NUMBER
java.lang.Byte TINYINT NUMBER
java.lang.Short SMALLINT NUMBER
java.lang.Integer INTEGER NUMBER
java.lang.Long BIGINT NUMBER
java.lang.Float REAL NUMBER
java.lang.Double FLOAT, DOUBLE NUMBER
SQLJ STREAM CLASSES
sqlj.runtime.BinaryStream LONGVARBINARY LONG RAW
sqlj.runtime.CharacterStream LONGVARCHAR LONG
sqlj.runtime.AsciiStream LONGVARCHAR LONG
(Deprecated; use CharacterStream.)
sqlj.runtime.UnicodeStream LONGVARCHAR LONG
(Deprecated; use CharacterStream.)
ORACLE EXTENSIONS
oracle.sql.NUMBER NUMBER NUMBER
oracle.sql.CHAR CHAR CHAR
oracle.sql.RAW RAW RAW
oracle.sql.DATE DATE DATE
oracle.sql.TIMESTAMP TIMESTAMP TIMESTAMP
oracle.sql.TIMESTAMPTZ TIMESTAMPTZ TIMESTAMP-WITH-
TIMEZONE
oracle.sql.TIMESTAMPLTZ TIMESTAMPLTZ TIMESTAMP-WITH-
LOCAL-TIMEZONE
oracle.sql.ROWID ROWID ROWID
oracle.sql.BLOB BLOB BLOB
oracle.sql.CLOB CLOB CLOB
oracle.sql.BFILE BFILE BFILE
oracle.sql.STRUCT STRUCT Object types
oracle.sql.REF REF Reference types
oracle.sql.ARRAY ARRAY Collection types
oracle.sql.OPAQUE OPAQUE OPAQUE types
Custom object classes implementing STRUCT Object types
oracle.sql.ORAData
Custom reference classes implementing REF Reference types
oracle.sql.ORAData
Custom collection classes implementing ARRAY Collection types
oracle.sql.ORAData
6-3
Chapter 6
Table 6-1 (Cont.) Type Mappings for Supported Host Expression Types

Custom classes implementing OPAQUE OPAQUE types
oracle.sql.ORAData for OPAQUE types
(for example, oracle.xdb.XMLType)
Other custom Java classes implementing Any Any
oracle.sql.ORAData (to wrap any
oracle.sql type)
SQLJ object Java types (can implement JAVA_STRUCT SQLJ object SQL
either SQLData or ORAData) types (JAVA_STRUCT
behind the scenes;
automatic conversion to
an appropriate Java
class)
JAVA TYPES FOR PL/SQL TYPES
Scalar indexed-by table represented NA NA
by a Java numeric array or an Note: There is a
array of String, oracle.sql.CHAR, or PLSQL_INDEX_TABLE
oracle.sql.NUMBER type, but it does not
appear to be used
externally.
GLOBALIZATION SUPPORT
oracle.sql.NCHAR CHAR CHAR
oracle.sql.NString CHAR VARCHAR CHAR VARCHAR2 LONG
LONGVARCHAR
oracle.sql.NCLOB CLOB CLOB
oracle.sqlj.runtime.NcharCharact LONGVARCHAR LONG
erStream
oracle.sqlj.runtime. LONGVARCHAR LONG
NcharAsciiStream (Deprecated; use
NcharCharacterStream.)
oracle.sqlj.runtime. LONGVARCHAR LONG
NcharUnicodeStream (Deprecated; use
NcharCharacterStream.)
QUERY RESULT OBJECTS
java.sql.ResultSet CURSOR CURSOR
SQLJ iterator objects CURSOR CURSOR
See Also:
Oracle Database JDBC Developer's Guide for more information about Oracle
type support.
The following points relate to type support for standard features:
6-4
Chapter 6
• JDBC and SQLJ do not support Java char and Character types. Instead, use the
Java String type to represent character data.
• Do not confuse the supported java.sql.Date type with java.util.Date, which is
not directly supported. The java.sql.Date class is a wrapper for java.util.Date
that enables JDBC to identify the data as a SQL DATE and adds formatting and
parsing operations to support JDBC escape syntax for date values.
• Remember that all numeric types in Oracle Database 12c Release 2 (12.2) are
stored as NUMBER. Although you can specify additional precision when you declare
a NUMBER during table creation, this precision may be lost when retrieving the data
through Oracle JDBC drivers, depending on the Java type that you use to receive
the data. An oracle.sql.NUMBER instance would preserve full information.
• The Java wrapper classes, such as Integer and Float, are useful in cases where
NULL may be returned by the SQL statement. Primitive types, such as int and
float, cannot contain null values.
See Also:
"NULL-Handling"
• The SQLJ stream classes are required in using streams as host variables.
See Also:
"Support for Streams"
• Weak types cannot be used for OUT or INOUT parameters. This applies to the
Struct, Ref, and Array standard JDBC 2.0 types, as well as to corresponding
Oracle extended types.
• A new set of interfaces, in the oracle.jdbc package, was first added in the
Oracle9i JDBC implementation in place of classes of the oracle.jdbc.driver
package. These interfaces provide a more generic way for users to access Oracle-
specific features using Oracle JDBC drivers. Specifically, when creating programs
for the middle tier, you should use the oracle.jdbc application programming
interface (API). However, SQLJ programmers will not typically use these interfaces
directly. They are used transparently by the SQLJ run time or in Oracle-specific
generated code.
See Also:
"Custom Java Class Interface Specifications"
• For information about SQLJ support for result set and iterator host variables, refer
to "Using Iterators and Result Sets as Host Variables"Using Iterators and Result
Sets as Stored Function Returns.
The following points relate to Oracle extensions:
6-5
Chapter 6
• The Oracle SQLJ implementation requires any class that implements

oracle.sql.ORAData to set the static _SQL_TYPECODE parameter according to
values defined in the OracleTypes class. In some cases, an additional parameter
must be set as well, such as _SQL_NAME for objects and _SQL_BASETYPE for object
references.
• The oracle.sql classes are wrappers for SQL data for each of the Oracle data
types. The ARRAY, STRUCT, REF, BLOB, and CLOB classes correspond to standard
JDBC 2.0 interfaces.
See Also:
Oracle Database JDBC Developer's Guide for information about these
classes and Oracle extensions
• Custom Java classes can map to Oracle objects, which implement ORAData or
SQLData, references, which implement ORAData only, collections, which implement
ORAData only, OPAQUE types, which implement ORAData only, or other SQL types for
customized handling, which implement ORAData only.
• The Oracle SQLJ implementation has functionality for automatic blank padding
when comparing a string to a CHAR column value for a WHERE clause. Otherwise the
string would have to be padded to match the number of characters in the database
column. This is available as a SQLJ translator option for Oracle-specific code
generation, or as an Oracle customizer option for ISO standard code generation.
• Weak types cannot be used for OUT or INOUT parameters. This applies to the
STRUCT, REF, and ARRAY Oracle extended types and corresponding standard JDBC
2.0 types, as well as to Oracle OPAQUE types.
• Using any of the Oracle extensions requires the following:
– Oracle JDBC driver
– Oracle-specific code generation or Oracle customization during translation
– Oracle SQLJ run time when your application runs
6.1.2 Supported Types and Requirements for JDBC 2.0

As indicated in Table 6-1, the Oracle JDBC and SQLJ implementations support JDBC
2.0 types in the standard java.sql package. This section lists JDBC 2.0 supported
types and related Oracle extensions.
Table 6-2 lists the JDBC 2.0 types supported by the Oracle SQLJ implementation.
You can use them wherever you can use the corresponding Oracle extensions,
summarized in the table.
The Oracle extensions have been available in prior releases and are still available as
well. These oracle.sql.* classes provide functionality to wrap raw SQL data.
See Also:
6-6
Chapter 6
Table 6-2 Correlation between Oracle Extensions and JDBC 2.0 Types
JDBC 2.0 Type Oracle Extension

java.sql.Blob oracle.sql.BLOB
java.sql.Clob oracle.sql.CLOB
java.sql.Struct oracle.sql.STRUCT
java.sql.Ref oracle.sql.REF
java.sql.Array oracle.sql.ARRAY
java.sql.SQLData NA
NA oracle.sql.ORAData (_SQL_TYPECODE =
OracleTypes.STRUCT)
ORAData functionality is an Oracle-specific alternative to standard SQLData functionality

for Java support of user-defined types.
See Also:
"Custom Java Classes", "Support for BLOB_ CLOB_ and BFILE", and
"Support for Weakly Typed Objects_ References_ and Collections"
The following JDBC 2.0 types are currently not supported in the Oracle JDBC and
SQLJ implementations:
• JAVA_OBJECT: Represents an instance of a Java type in a SQL column.
• DISTINCT: A distinct SQL type represented in or retrievable from a basic SQL type.
For example, SHOESIZE --> NUMBER.
Note:
Beginning with Oracle Database 11g, the Oracle SQLJ implementation
supports the ISO SQLJ feature of allowing array types for iterator columns.
You can declare an iterator that uses java.sql.Array or oracle.sql.ARRAY
columns. For example, suppose the following database table is defined:
CREATE OR REPLACE TYPE arr_type IS VARRAY(20) OF NUMBER;
CREATE TABLE arr_type (arr_col1 arr_type, arr_col2
arr_type);
You could define a corresponding iterator type as follows:

#sql static iterator MyIter (oracle.sql.ARRAY arr_col1,
java.sql.Array arr_col2);
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6.1.3 Using PL/SQL BOOLEAN, RECORD Types, and TABLE Types

The Oracle SQLJ and JDBC implementations do not support calling arguments or
return values of the PL/SQL BOOLEAN type or RECORD types.
Support for TABLE Types

Oracle JDBC drivers support scalar PL/SQL indexed-by tables.
See Also:
The Oracle SQLJ implementation simplifies the process of writing and retrieving data
in scalar indexed-by tables. The following array types are supported:
• Numeric types: int[], long[], float[], double[], short[],
java.math.BigDecimal[], oracle.sql.NUMBER[]
• Character types: java.lang.String[], oracle.sql.CHAR[]
The following is an example of writing indexed-by table data to the database:
int[] vals = {1,2,3};
#sql { call procin(:vals) };
The following is an example of retrieving indexed-by table data from the database:
oracle.sql.CHAR[] outvals;
#sql { call procout(:OUT outvals/*[111](22)*/) };
You must specify the maximum length of the output array being retrieved, using the
[xxx] syntax inside the /*...*/ syntax, as shown. Also, for character-like binds, you
can optionally include the (xx) syntax, as shown, to specify the maximum length of an
array element in bytes.
Note:
The oracle.sql.Datum class is not supported directly. You must use an
appropriate subclass, such as oracle.sql.CHAR or oracle.sql.NUMBER.
Workarounds for Unsupported Types

As a workaround for an unsupported type, you can create wrapper procedures that
process the data using supported types. For example, to wrap a stored procedure
that uses PL/SQL boolean values, you can create a stored procedure that takes a
character or number from JDBC and passes it to the original procedure as BOOLEAN,
or for an output parameter, accepts a BOOLEAN argument from the original procedure
and passes it as a CHAR or NUMBER to JDBC. Similarly, to wrap a stored procedure that
uses PL/SQL records, you can create a stored procedure that handles a record in its
individual components, such as CHAR and NUMBER. To wrap a stored procedure that
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uses PL/SQL TABLE types, you can break the data into components or perhaps use
Oracle collection types.
The following is an example of a PL/SQL wrapper procedure MY_PROC for a stored
procedure PROC that takes a BOOLEAN as input:
PROCEDURE MY_PROC (n NUMBER) IS
BEGIN
IF n=0
THEN proc(false);
ELSE proc(true);
END IF;
END;
PROCEDURE PROC (b BOOLEAN) IS

BEGIN
...
END;
6.1.4 Backward Compatibility for Previous Oracle JDBC Releases

This section summarizes backward compatibility issues when using the Oracle SQLJ
implementation with earlier Oracle JDBC releases.
In Oracle Database 11g release 1 (11.1), SQLJ fully supports applications developed
in Oracle9i Database and Oracle Database 10g release 1 (10.1). However, in Oracle
Database 11g release 1 (11.1), JDBC resources are no longer closed by the SQLJ
run time resource finalizers. Therefore, some applications developed prior to Oracle
Database 11g release 1 (11.1) may observe JDBC connection and statement leaking.
To prevent such leaking, you must properly close all the SQLJ run-time resources,
such as connection context, execution context, and iterator, in your SQLJ applications.
Note:
Oracle9i release 2 first added support for OPAQUE types and TIMESTAMP
types.
Backward Compatibility for Oracle8i Database

The following Oracle Database 11g features, which are also available in Oracle9i
Database, are not supported or supported differently in the Oracle8i JDBC drivers:
• The oracle.sql.ORAData and ORADataFactory interfaces for Java mapping of
user-defined SQL types
Use the oracle.sql.CustomDatum and CustomDatumFactory interfaces instead.
• Oracle extensions for character types for globalization support: NCHAR,
NCLOB, NString, and NcharCharacterStream (or NcharAsciiStream and
NcharUnicodeStream in earlier releases)
6.2 Support for Streams

Standard SQLJ provides the following specialized classes for convenient processing of
long data in streams:
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• sqlj.runtime.BinaryStream
• sqlj.runtime.CharacterStream
These stream types can be used for iterator columns to retrieve data from the
database or for input host variables to send data to the database. As with
Java streams in general, these classes allow the convenience of processing and
transferring large data items in manageable chunks.
This section discusses general use of these classes, Oracle SQLJ extended
functionality, and stream class methods. It covers the following topics:
• General Use of SQLJ Streams
• Key Aspects of Stream Support Classes
• Using SQLJ Streams to Send Data
• Retrieving Data into Streams: Precautions
• Using SQLJ Streams to Retrieve Data
• Stream Class Methods
• Examples of Retrieving and Processing Stream Data
• SQLJ Stream Objects as Output Parameters and Function Return Values
Note:
Starting from JDBC 2.0, the CharacterStream class replaces the
AsciiStream and UnicodeStream classes. CharacterStream shelters users
from unnecessary logistics regarding encoding.
6.2.1 General Use of SQLJ Streams

Table 6-1 lists the data types you would typically process using these stream classes.
To summarize:
• BinaryStream is typically used for LONG RAW (Types.LONGVARBINARY), but might
also be used for RAW (Types.BINARY or Types.VARBINARY).
• CharacterStream is typically used for LONG (java.sql.Types.LONGVARCHAR), but
might also be used for VARCHAR2 (Types.VARCHAR).
Of course, any use of streams is at your discretion. You can use the SQLJ stream
types for host variables to either send or retrieve data.
As Table 6-1 documents, LONG and VARCHAR2 data can also be manifested in Java
String, while RAW and LONGRAW data can also be manifested in Java byte[] arrays.
Also, if your database supports large object types, such as BLOB and CLOB, then you
may find these to be preferable to types like LONG and LONG RAW, although streams
might still be used in extracting data from large objects. The Oracle SQLJ and JDBC
implementations support large object types.
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See Also:
"Support for BLOB_ CLOB_ and BFILE"
Both SQLJ stream classes are subclasses of standard Java classes,

java.io.InputStream for BinaryStream and java.io.Reader for CharacterStream,
and act as wrappers to provide the functionality required by SQLJ. This functionality is
to communicate to SQLJ the type and length of the underlying data so that it can be
processed and formatted properly.
6.2.2 Key Aspects of Stream Support Classes

The following abbreviated code illustrates key aspects of the BinaryStream class, such
as what it extends, constructor signatures, and key method signatures:
public class sqlj.runtime.BinaryStream extends sqlj.runtime.StreamWrapper
{ public sqlj.runtime.BinaryStream(java.io.InputStream);
public sqlj.runtime.BinaryStream(java.io.InputStream,int);
public java.io.InputStream getInputStream();
public int getLength();
public void setLength(int);
}
The following abbreviated code illustrates key aspects of the CharacterStream class:
public class sqlj.runtime.CharacterStream extends java.io.FilterReader
{ public sqlj.runtime.CharacterStream(java.io.Reader);
public sqlj.runtime.CharacterStream(java.io.Reader,int);
public int getLength();
public java.io.Reader getReader();
public void setLength(int);
}
Note:
• The int parameters in the constructors are for data length, in bytes or
characters as applicable.
• For any method that takes a java.io.InputStream object as input, you
can use a BinaryStream object instead. Similarly, for any method that
takes a java.io.Reader object as input, you can use a CharacterStream
object instead.
• The deprecated AsciiStream and UnicodeStream classes have the same
key aspects and signatures as BinaryStream.
6.2.3 Using SQLJ Streams to Send Data

Standard SQLJ enables you to use streams as host variables to update the database.
A key point in sending a SQLJ stream to the database is that you must somehow
determine the length of the data and specify that length to the constructor of the SQLJ
stream.
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You can use a SQLJ stream to send data to the database as follows:
1. Determine the length of the data.
2. Create an appropriate standard Java data object for input. For BinaryStream,
this would be an input stream, an instance of java.io.InputStream or some
subclass. For CharacterStream, this would be a reader object, an instance of
java.io.Reader or some subclass.
3. Create an instance of the appropriate SQLJ stream class depending on the type of
data, passing the data object and length to the constructor.
4. Use the SQLJ stream instance as a host variable in a suitable SQL operation in a
SQLJ executable statement.
5. Close the stream.
Note:
Although not required, it is recommended that you close the stream after
using it.
Updating LONG or LONG RAW from a File

This section illustrates how to create a CharacterStream object or a BinaryStream
object from a File object and use it to update the database. The code example at the
end uses a CharacterStream for a LONG column.
In updating a database column from a file, a step is needed to determine the length.
You can do this by creating a java.io.File object before you create your input
stream.
Following are the steps for updating the database from a file:
1. Create a java.io.File object from your file. You can specify the file path name to
the File class constructor.
2. Use the length() method of the File object to determine the length of the data.
This method returns a long value, which you must cast to an int for input to the
SQLJ stream class constructor.
Note:
Before performing this cast, test the long value to ensure that it is not too
big to fit into an int variable. The static constant MAX_VALUE in the class
java.lang.Integer indicates the largest possible Java int value.
3. For character data, create a java.io.FileReader object from the File object. You
can pass the File object to the FileReader constructor.
For binary data, create a java.io.FileInputStream object from the File object.
You can pass the File object to the FileInputStream constructor.
4. Create an appropriate SQLJ stream object. This would be a CharacterStream
object for a character file or a BinaryStream object for a binary file. Pass the
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FileReader or FileInputStream object, as applicable, and the data length as an

int to the SQLJ stream class constructor.
5. Use the SQLJ stream object as a host variable in an appropriate SQL operation in
a SQLJ executable statement.
The following is an example of writing LONG data to the database from a file. Presume
you have an HTML file in /private/mydir/myfile.html and want to insert the file
contents into a LONG column, chardata, in the filetable database table.
import java.io.*;
...
File myfile = new File ("/private/mydir/myfile.html");
int length = (int)myfile.length(); // Must cast long output to int.
FileReader filereader = new FileReader(myfile);
CharacterStream charstream = new CharacterStream(filereader, length);
#sql { INSERT INTO filetable (chardata) VALUES (:charstream) };
charstream.close();
...
Updating LONG RAW from a Byte Array

This section illustrates how to create a BinaryStream object from a byte array and
uses it to update the database.
You must determine the length of the data before updating the database from a byte
array. This is more trivial for arrays than for files, though, because all Java arrays have
functionality to return the length.
Following are the steps in updating the database from a byte array:
1. Use the length functionality of the array to determine the length of the data. This
returns an int, which is what you will need for the constructor of any of the SQLJ
stream classes.
2. Create a java.io.ByteArrayInputStream object from your array. You can pass
the byte array to the ByteArrayInputStream constructor.
3. Create a BinaryStream object. Pass the ByteArrayInputStream object and data
length as an int to the BinaryStream class constructor.
The constructor signature is as follows:
BinaryStream (InputStream in, int length)
You can use an instance of java.io.InputStream or of any subclass, such as the

ByteArrayInputStream class.
4. Use the SQLJ stream object as a host variable in an appropriate SQL operation in
a SQLJ executable statement.
The following is an example of writing LONG RAW data to the database from a byte
array. Presume you have a byte array, bytearray[], and you want to insert its
contents into a LONG RAW column, BINDATA, in the BINTABLE database table.
import java.io.*;
...
byte[] bytearray = new byte[100];
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(Populate bytearray somehow.)

...
int length = bytearray.length;
ByteArrayInputStream arraystream = new ByteArrayInputStream(bytearray);
BinaryStream binstream = new BinaryStream(arraystream, length);
#sql { INSERT INTO bintable (bindata) VALUES (:binstream) };
binstream.close();
...
Note:
It is not necessary to use a stream as in this example. Alternatively, you can
update the database directly from a byte array.
6.2.4 Retrieving Data into Streams: Precautions

You can also use the SQLJ stream classes to retrieve data, but the logistics of using
streams make certain precautions necessary with some database products. When
reading long data and writing it to a stream using Oracle Database 12c Release 2
(12.2) and an Oracle JDBC driver, you must be careful in how you access and process
the stream data.
As Oracle JDBC drivers access data from an iterator row, they must flush any stream
item from the communications pipe before accessing the next data item. Even though
the stream data is written to a local stream while the iterator row is processed, this
stream data will be lost if you do not read it from the local stream before the JDBC
driver accesses the next data item. This is because of the manner in which streams
must be processed, which is due to their potentially large size and unknown length.
Therefore, as soon as your Oracle JDBC driver has accessed a stream item and
written it to a local stream variable, you must read and process the local stream before
anything else is accessed from the iterator.
This is especially problematic in using positional iterators, with their requisite FETCH
INTO syntax. With each fetch, all columns are read before any are processed.
Therefore, there can be only one stream item and it must be the last item accessed.
The precautions you must take can be summarized as follows:
• When using a positional iterator, you can have only one stream column and it must
be the last column. As soon as you have fetched each row of the iterator, writing
the stream item to a local input stream variable in the process, you must read and
process the local stream variable before advancing to the next row of the iterator.
• When using a named iterator, you can have multiple stream columns. However,
as you process each iterator row, each time you access a stream field, writing the
data to a local stream variable in the process, you must read and process the local
stream immediately, before reading anything else from the iterator.
Furthermore, in processing each row of a named iterator, you must call the column
accessor methods in the same order in which the database columns were selected
in the query that populated the iterator. As mentioned in the preceding discussion,
this is because stream data remains in the communications pipe after the query. If
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you try to access columns out of order, then the stream data may be skipped over
and lost in the course of accessing other columns.
Note:
• Oracle Database 12c Release 2 (12.2) and Oracle JDBC drivers do not
support use of streams in SELECT INTO statements.
• Input streams, by default, do not support mark and reset methods. If
you pass any arbitrary input stream to the constructor, then the reset
method of InputStream class will throw an IOException. So, always
ensure that the input stream is in the proper state when passed to the
NcharAsciiStream constructor. For example, reset the stream before
passing it to NcharAsciiStream if the stream has no more data or if the
stream is closed.
6.2.5 Using SQLJ Streams to Retrieve Data

To retrieve data as a stream, standard SQLJ enables you to select data into a named
or positional iterator that has a column of the appropriate SQLJ stream type.
This section covers the basic steps in retrieving data into a SQLJ stream using a
positional iterator or a named iterator, taking into account the precautions documented
in the preceding section.
See Also:
"Stream Class Methods" and "Examples of Retrieving and Processing
Stream Data"
Using a SQLJ Stream Column in a Positional Iterator

Use the following steps to retrieve data into a SQLJ stream using a positional iterator:
1. Declare a positional iterator class with the last column being of the appropriate
SQLJ stream type.
2. Declare a local variable of your iterator type.
3. Declare a local variable of the appropriate SQLJ stream type. This will be used as
a host variable to receive data from each row of the SQLJ stream column of the
iterator.
4. Execute a query to populate the iterator you declared in Step 2.
5. Process the iterator as usual. Because the host variables in the INTO-list of the
FETCH INTO statement must be in the same order as the columns of the positional
iterator, the local input stream variable is the last host variable in the list.
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See Also:
"Using Positional Iterators"
6. In the iterator processing loop, after each iterator row is accessed, immediately
read and process the local input stream, storing or printing the stream data as
desired.
7. Close the local input stream each time through the iterator processing loop.
8. Close the iterator.
Note:
Although not required, it is recommended that you close the local input
stream each time through the iterator processing loop.
<<<[for 11g?] Use code examples. >>>
Using SQLJ Stream Columns in a Named Iterator

Use the following steps to retrieve data into one or more SQLJ streams using a named
iterator:
1. Declare a named iterator class with one or more columns of appropriate SQLJ
stream type.
2. Declare a local variable of your iterator type.
3. Declare a local variable of some input stream or reader type for each SQLJ
stream column in the iterator. These will be used to receive data from the stream-
column accessor methods. These local stream variables need not be of the SQLJ
stream types. They can be standard java.io.InputStream or java.io.Reader, as
applicable.
Note:
The local stream variables need not be of the SQLJ stream types,
because the data was already correctly formatted as a result of the
iterator columns being of appropriate SQLJ stream types.
4. Execute a query to populate the iterator you declared in Step 2.

5. Process the iterator as usual. In processing each row of the iterator, as
each stream-column accessor method returns the stream data, write it to the
corresponding local input stream variable you declared in Step 3.
To ensure that stream data will not be lost, call the column accessor methods in
the same order in which columns were selected in the query in Step 4.
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See Also:
"Using Positional Iterators"
6. In the iterator processing loop, immediately after calling the accessor method for
any stream column and writing the data to a local input stream variable, read and
process the local input stream, storing or printing the stream data as desired.
7. Close the local input stream each time through the iterator processing loop.
8. Close the iterator.
<<<[for 11g?] Use code examples. >>>
Note:
• When you populate a SQLJ stream object with data, the length attribute
of the stream will not be meaningful. This attribute is meaningful only
when you set it explicitly, either using the setLength() method that each
SQLJ stream class provides or specifying the length to the constructor.
• Although not required, it is recommended that you close the local input
stream each time through the iterator processing loop.
6.2.6 Stream Class Methods

In processing a SQLJ stream column in a named or positional iterator, the local stream
variable used to receive the stream data can be either a SQLJ stream type or the
standard java.io.InputStream or java.io.Reader type, as applicable. In either case,
standard methods of the input data object are supported.
If the local stream variable is a SQLJ stream type, BinaryStream or CharacterStream,
you have the option of either reading data directly from the SQLJ stream object or
retrieving the underlying InputStream or Reader object and reading data from that.
Note:
This is just a matter of preference. The former approach is simpler. However,
the latter approach involves more direct and efficient data access.
Binary Stream Methods

The BinaryStream class is a subclass of the sqlj.runtime.StreamWrapper class. The
StreamWrapper class provides the following key methods:
• InputStream getInputStream(): You can optionally use this method to get the
underlying java.io.InputStream object. However, this is not required, because
you can also process SQLJ stream objects directly.
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• void setLength(int length): You can use this to set the length attribute of
a SQLJ stream object. This is not necessary if you have already set length in
constructing the stream object, unless you want to change it for some reason.
The length attribute must be set to an appropriate value before you send a SQLJ
stream to the database.
• int getLength(): This method returns the value of the length attribute of a SQLJ
stream. This value is meaningful only if you explicitly set it using the stream object
constructor or the setLength() method. When you retrieve data into a stream, the
length attribute is not set automatically.
The sqlj.runtime.StreamWrapper class is a subclass of the
java.io.FilterInputStream class, which is a subclass of the java.io.InputStream
class. The following important methods of the InputStream class are supported by the
SQLJ BinaryStream class as well:
• int read (): Reads the next byte of data from the input stream. The byte of data
is returned as an int value in the range 0 to 255. If the end of the stream has
already been reached, then the value -1 is returned. This method blocks program
execution until one of the following:
– Input data is available
– The end of the stream is detected
– An exception is thrown
• int read (byte b[]): Reads up to b.length bytes of data from the input stream,
writing the data into the specified b[] byte array. It returns an int value indicating
how many bytes were read, or -1 if the end of the stream has already been
reached. This method blocks program execution until input is available.
• int read (byte b[], int off, int len): Reads up to len bytes of data from
the input stream, starting at the byte specified by the offset, off, and writing the
data into the specified b[] byte array. It returns an int value indicating how many
bytes were read, or -1 if the end of the stream has already been reached. This
method blocks until input is available.
• long skip (long n): Skips over and discards n bytes of data from the input
stream. However, in some circumstances, this method will actually skip a smaller
number of bytes. It returns a long value indicating the actual number of bytes
skipped.
• void close(): Closes the stream and releases any associated resources.
Character Stream Methods

The CharacterStream class provides the following key methods:
• Reader getReader(): You can optionally use this method to get the underlying
java.io.Reader object. However, this is not required, because you can also
process SQLJ stream objects directly.
• void setLength(int length): You can use this method to set the length of the
stream object.
• int getLength(): You can use this method to get the length of the stream object.
The sqlj.runtime.CharacterStream class is a subclass of the java.io.FilterReader
class, which is a subclass of the java.io.Reader class. The following important
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methods of the Reader class are supported by the SQLJ CharacterStream class as
well:
• int read (): Reads the next character of data from the reader. The data is
returned as an int value in the range 0 to 65535. If the end of the data has
already been reached, then the value -1 is returned. This method blocks program
execution until one of the following:
– Input data is available
– The end of the data is detected
– An exception is thrown
• int read (char cbuf[]): Reads characters into an array, writing the data into
the specified cbuf[] char array. It returns an int value indicating how many
characters were read, or -1 if the end of the data has already been reached. This
method blocks program execution until input is available.
• int read (char cbuf[], int off, int len): Reads up to len characters of
data from the input, starting at the character specified by the offset, off, and
writing the data into the specified char[] char array. It returns an int value
indicating how many characters were read, or -1 if the end of the data has already
been reached. This method blocks until input is available.
• long skip (long n): Skips over and discards n characters of data from the input.
However, in some circumstances, this method will actually skip a smaller number
of characters. It returns a long value indicating the actual number of characters
skipped.
• void close(): Closes the stream and releases any associated resources.
6.2.7 Examples of Retrieving and Processing Stream Data

This section provides examples of various scenarios of retrieving stream data, as
follows:
• Using a SELECT statement to select data from a LONG column and populate a SQLJ
CharacterStream column in a named iterator, as shown in Example 6-1
• Using a SELECT statement to select data from a LONG RAW column and populate a
SQLJ BinaryStream column in a positional iterator, as shown in Example 6-2
Example 6-1 Selecting LONG Data into CharacterStream Column of Named
Iterator
This example selects data from a LONG database column, populating a SQLJ
CharacterStream column in a named iterator.
Assume there is a table named FILETABLE with a VARCHAR2 column called FILENAME
that contains file names and a LONG column called FILECONTENTS that contains file
contents in character format. The code is as follows:
import java.io.*;
...
#sql iterator MyNamedIter (String filename, CharacterStream filecontents);
...
MyNamedIter namediter = null;
String fname;
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CharacterStream charstream;
#sql namediter = { SELECT filename, filecontents FROM filetable };
while (namediter.next()) {
fname = namediter.filename();
charstream = namediter.filecontents();
System.out.println("Contents for file " + fname + ":");
printStream(charstream);
charstream.close();
}
namediter.close();
...
public void printStream(Reader in) throws IOException
{
int character;
while ((character = in.read()) != -1) {
System.out.print((char)character);
}
}
Remember that you can pass a SQLJ character stream to any method that takes a
standard java.io.Reader as an input parameter.
Example 6-2 : Selecting LONG RAW Data into BinaryStream Column of

Positional Iterator
This example selects data from a LONG RAW column, populating a SQLJ BinaryStream
column in a positional iterator.
As explained in the preceding section, there can be only one stream column in a
positional iterator and it must be the last column. Assume there is a table named
BINTABLE with a NUMBER column called IDENTIFIER and a LONG RAW column called
BINDATA that contains binary data associated with the identifier. The code is as follows:
...
#sql iterator MyPosIter (int, BinaryStream);
...
MyPosIter positer = null;
int id=0;
BinaryStream binstream=null;
#sql positer = { SELECT identifier, bindata FROM bintable };
while (true) {
#sql { FETCH :positer INTO :id, :binstream };
if (positer.endFetch()) break;
(...process data as desired...)
binstream.close();
}
positer.close();
...
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6.2.8 SQLJ Stream Objects as Output Parameters and Function

Return Values
As described in the preceding sections, standard SQLJ supports the use of the
BinaryStream and CharacterStream classes in the sqlj.runtime package for retrieval
of stream data into iterator columns.
In addition, the Oracle SQLJ implementation enables the following uses of the SQLJ
stream types if you use Oracle9i Database or later version, an Oracle JDBC driver,
Oracle-specific code generation or Oracle customizer, and Oracle SQLJ run time:
• They can appear as OUT or INOUT host variables from a stored procedure or
function call.
• They can appear as the return value from a stored function call.
Streams as Stored Procedure Output Parameters

You can use the BinaryStream and CharacterStream types as the assignment type for
a stored procedure or stored function OUT or INOUT parameter.
Assume the following table definition:

CREATE TABLE streamexample (name VARCHAR2 (256), data LONG);
INSERT INTO streamexample (data, name)
VALUES
('0000000000111111111112222222222333333333344444444445555555555',
'StreamExample');
Also, presume the following stored procedure definition, which uses the
STREAMEXAMPLE table:
CREATE OR REPLACE PROCEDURE out_longdata
(dataname VARCHAR2, longdata OUT LONG) IS
BEGIN
SELECT data INTO longdata FROM streamexample WHERE name = dataname;
END out_longdata;
The following sample code uses a call to the out_longdata stored procedure to read
the long data:
...
CharacterStream data;
#sql { CALL out_longdata('StreamExample', :OUT data) };
int c;
while ((c = data.read ()) != -1)
System.out.print((char)c);
System.out.flush();
data.close();
...
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Support for JDBC 2.0 LOB Types and Oracle Type Extensions
Note:
Closing the stream is recommended, but not required.
Streams as Stored Function Results

You can use the BinaryStream and CharacterStream types as the assignment type for
a stored function return result.
Assume the same STREAMEXAMPLE table definition as in the preceding stored procedure
example. Also, assume the following stored function definition, which uses the
STREAMEXAMPLE table:
CREATE OR REPLACE FUNCTION get_longdata (dataname VARCHAR2) RETURN long
IS longdata LONG;
BEGIN
SELECT data INTO longdata FROM streamexample WHERE name = dataname;
RETURN longdata;
END get_longdata;
The following sample code uses a call to the get_longdata stored function to read the
long data:
...
CharacterStream data;
#sql data = { VALUES(get_longdata('StreamExample')) };
int c;
while ((c = data.read ()) != -1)
System.out.print((char)c);
System.out.flush();
data.close();
...
Note:
Closing the stream is recommended, but not required.
6.3 Support for JDBC 2.0 LOB Types and Oracle Type
Extensions
The Oracle SQLJ implementation offers extended functionality for the following JDBC
2.0 and Oracle-specific data types:
• JDBC 2.0 large object (LOB) types (BLOB and CLOB)
• Oracle BFILE type
• Oracle ROWID type
• Oracle REF CURSOR types
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• Other Oracle Database 12c Release 2 (12.2) data types, such as NUMBER and RAW
These data types are supported by classes in the oracle.sql package. LOBs and
binary files (BFILEs) are handled similarly in many ways, so are discussed together.
Additionally, the Oracle SQLJ implementation offers extended support for the standard
BigDecimal JDBC type.
JDBC 2.0 functionality for user-defined SQL objects, object references, and collections
are also supported.
See Also:
Objects_ Collections_ and OPAQUE Types
Note that using Oracle extensions in your code requires the following:
• Use one of Oracle JDBC drivers.
• Use Oracle-specific code generation or for ISO code generation,
customize the profiles appropriately. The default customizer,
oracle.sqlj.runtime.util.OraCustomizer, is recommended.
• Use Oracle SQLJ run time when your application runs.
Oracle SQLJ run time and an Oracle JDBC driver are required whenever you use
Oracle customizer, even if you do not actually use Oracle extensions in your code.
For Oracle-specific semantics-checking, you must use an appropriate checker. The
default checker, oracle.sqlj.checker.OracleChecker, acts as a front end and will
run the appropriate checker based on your environment. This will be one of the Oracle
specific checkers if you are using an Oracle JDBC driver.
• Package oracle.sql
• Support for BLOB_ CLOB_ and BFILE
• Support for Oracle ROWID
• Support for Oracle REF CURSOR Types
• Support for Other Oracle Database 11g Data Types
• Extended Support for BigDecimal
6.3.1 Package oracle.sql

SQLJ users, as well as JDBC users, should be aware of the oracle.sql package,
which includes classes to support all the Oracle Database 12c Release 2 (12.2)
data types, such as oracle.sql.ROWID, oracle.sql.CLOB, and oracle.sql.NUMBER.
The oracle.sql classes are wrappers for the raw SQL data and provide appropriate
mappings and conversion methods to Java formats. An oracle.sql.* object contains
a binary representation of the corresponding SQL data in the form of a byte array.
Each oracle.sql.* data type class is a subclass of the oracle.sql.Datum class.

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See Also:
• "Connection Options"
• "Semantics-Checking and Offline-Parsing Options"
• Oracle Database JDBC Developer's Guide
6.3.2 Support for BLOB, CLOB, and BFILE

The Oracle SQLJ and JDBC implementations support JDBC 2.0 LOB types and
provide similar support for the Oracle specific BFILE type (read-only binary files stored
outside the database). These data types are supported by the following classes:
• oracle.sql.BLOB
• oracle.sql.CLOB
• oracle.sql.BFILE
These classes can be used in Oracle-specific SQLJ applications in the following ways:
• As IN, OUT, or INOUT host variables in executable SQLJ statements and in INTO-
lists
• As return values from stored function calls
• As column types in iterator declarations
See Also:
Oracle Database JDBC Developer's Guide for more information about LOBs
and BFILEs and use of supported stream APIs.
You can manipulate LOBs by using methods defined in the BLOB and CLOB classes,
which is recommended, or by using the procedures and functions defined in the
DBMS_LOB PL/SQL package. All procedures and functions defined in this package can
be called by SQLJ programs.
You can manipulate BFILEs by using methods defined in the BFILE class, which is
recommended, or by using the file-handling routines of the DBMS_LOB package.
Using methods of the BLOB, CLOB, and BFILE classes in a Java application is more
convenient than using the DBMS_LOB package and may also lead to faster execution in
some cases.
Note that the type of the chunk being read or written depends on the kind of LOB
being manipulated. For example, character large objects (CLOBs) contain character
data and, therefore, Java strings are used to hold chunks of data. Binary large objects
(BLOBs) contain binary data and, therefore, Java byte arrays are used to hold chunks
of data.
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Note:
The DBMS_LOB package requires a round trip to the server. Methods in the
BLOB, CLOB, and BFILE classes may also result in a round trip to the server.
BFILE Class versus DBMS_LOB Functionality for BFILEs

Example 6-3 and Example 6-4 contrast use of the oracle.sql methods with use of the
DBMS_LOB package for BFILEs:
BLOB and CLOB Classes versus DBMS_LOB Functionality for LOBs

Example 6-5 and Example 6-6 contrast use of the oracle.sql methods with use of the
DBMS_LOB package for BLOBs, and Example 6-7 and Example 6-8 contrast use of the
oracle.sql methods with use of the DBMS_LOB package for CLOBs.
LOB and BFILE Stored Function Results

Host variables of the BLOB, CLOB, and BFILE type can be assigned to the result of a
stored function call. The following example is for a CLOB, but code for BLOBs and
BFILEs would be functionally the same.
First, presume the following function definition:
CREATE OR REPLACE FUNCTION longer_clob (c1 CLOB, c2 CLOB) RETURN CLOB IS
result CLOB;
BEGIN
IF dbms_lob.getLength(c2) > dbms_lob.getLength(c1) THEN
result := c2;
ELSE
result := c1;
END IF;
RETURN result;
END longer_clob;
The following example uses a CLOB as the assignment type for a return value from
the longer_clob function:
void readFromLongest(CLOB c1, CLOB c2) throws SQLException
{
CLOB longest;
#sql longest = { VALUES(longer_clob(:c1, :c2)) };
readFromClob(longest);
}
The readFromLongest() method prints the contents of the longer passed CLOB, using
the readFromClob() method defined previously.
LOB and BFILE Host Variables and SELECT INTO Targets

Host variables of the BLOB, CLOB, and BFILE type can appear in the INTO-list of a
SELECT INTO executable statement. The following example is for a BLOB and CLOB,
but code for BFILEs would be functionally the same.
Assume the following table definition:
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Chapter 6
CREATE TABLE basic_lob_table(x VARCHAR2(30), b BLOB, c CLOB);

INSERT INTO basic_lob_table
VALUES('one', '010101010101010101010101010101', 'onetwothreefour');
INSERT INTO basic_lob_table
VALUES('two', '020202020202020202020202020202', 'twothreefourfivesix');
The following example uses a BLOB and a CLOB as host variables that receive data
from the table defined, using a SELECT INTO statement:
...
BLOB blob;
CLOB clob;
#sql { SELECT one.b, two.c INTO :blob, :clob
FROM basic_lob_table one, basic_lob_table two
WHERE one.x='one' AND two.x='two' };
#sql { INSERT INTO basic_lob_table VALUES('three', :blob, :clob) };
...
This example selects the BLOB from the first row and the CLOB from the second
row of BASIC_LOB_TABLE. It then inserts a third row into the table using the BLOB and
CLOB selected in the previous operation.
LOBs and BFILEs in Iterator Declarations

The BLOB, CLOB, and BFILE types can be used as column types for SQLJ positional and
named iterators. Such iterators can be populated as a result of compatible executable
SQLJ operations.
Following are sample declarations:
#sql iterator NamedLOBIter(CLOB c);
#sql iterator PositionedLOBIter(BLOB);
#sql iterator NamedFILEIter(BFILE bf);
LOB and BFILE Host Variables and Named Iterator Results

The following example uses the BASIC_LOB_TABLE table and the readFromLongest()
method defined in previous examples and a CLOB in a named iterator. Similar code
could be written for BLOBs and BFILEs.
#sql iterator NamedLOBIter(CLOB c);
...
NamedLOBIter iter;
#sql iter = { SELECT c FROM basic_lob_table };
if (iter.next())
CLOB c1 = iter.c();
if (iter.next())
CLOB c2 = iter.c();
iter.close();
readFromLongest(c1, c2);
...
This example uses an iterator to select two CLOBs from the first two rows of
BASIC_LOB_TABLE, then prints the larger of the two using the readFromLongest()
method.
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LOB and BFILE Host Variables and Positional Iterator FETCH INTO Targets
Host variables of the BLOB, CLOB, and BFILE type can be used with positional
iterators and appear in the INTO-list of the associated FETCH INTO statement if the
corresponding column attribute in the iterator is of the identical type.
The following example uses the BASIC_LOB_TABLE table and the writeToBlob()
method defined in previous examples. Similar code could be written for CLOBs and
BFILEs.
#sql iterator PositionedLOBIter(BLOB);
...
PositionedLOBIter iter;
BLOB blob = null;
#sql iter = { SELECT b FROM basic_lob_table };
for (long rowNum = 1; ; rowNum++)
{
#sql { FETCH :iter INTO :blob };
writeToBlob(blob, 512*rowNum);
}
iter.close();
...
This example calls writeToBlob() for each BLOB in BASIC_LOB_TABLE. Each row
writes an additional 512 bytes of data.
Example 6-3 Use of oracle.sql.BFILE File-Handling Methods with BFILE
This example manipulates a BFILE using file-handling methods of the
oracle.sql.BFILE class.
BFILE openFile (BFILE file) throws SQLException
{
String dirAlias, name;
dirAlias = file.getDirAlias();
name = file.getName();
System.out.println("name: " + dirAlias + "/" + name);
if (!file.isFileOpen())
{
file.openFile();
}
return file;
}
The BFILE getDirAlias() and getName() methods construct the full path and file
name. The openFile() method opens the file. You cannot manipulate BFILEs until
they have been opened.
Example 6-4 Use of DBMS_LOB File-Handling Routines with BFILE
This example manipulates a BFILE using file-handling routines of the DBMS_LOB
package.
BFILE openFile(BFILE file) throws SQLException
{
String dirAlias, name;
#sql { CALL dbms_lob.filegetname(:file, :out dirAlias, :out name) };
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System.out.println("name: " + dirAlias + "/" + name);
boolean isOpen;
#sql isOpen = { VALUES(dbms_lob.fileisopen(:file)) };
if (!isOpen)
{
#sql { CALL dbms_lob.fileopen(:inout file) };
}
return file;
}
The openFile() method prints the name of a file object and then returns an opened
version of the file. Note that BFILEs can be manipulated only after being opened with a
call to DBMS_LOB.FILEOPEN or equivalent method in the BFILE class.
Example 6-5 Example: Use of oracle.sql.CLOB Read Methods with CLOB

This example reads data from a CLOB using methods of the oracle.sql.CLOB class.
void readFromClob(CLOB clob) throws SQLException
{
long clobLen, readLen;
String chunk;
clobLen = clob.length();
for (long i = 0; i < clobLen; i+= readLen) {

chunk = clob.getSubString(i, 10);
readLen = chunk.length();
System.out.println("read " + readLen + " chars: " + chunk);
}
}
This method contains a loop that reads from the CLOB and returns a 10-character
Java string each time. The loop continues until the entire CLOB has been read.
Example 6-6 Example: Use of DBMS_LOB Read Routines with CLOB
This example uses routines of the DBMS_LOB package to read from a CLOB.
void readFromClob(CLOB clob) throws SQLException
{
long clobLen, readLen;
String chunk;
#sql clobLen = { VALUES(dbms_lob.getlength(:clob)) };
for (long i = 1; i <= clobLen; i += readLen) {

readLen = 10;
#sql { CALL dbms_lob.read(:clob, :inout readLen, :i, :out chunk) };
System.out.println("read " + readLen + " chars: " + chunk);
}
}
This method reads the contents of a CLOB in chunks of 10 characters at a time. Note
that the chunk host variable is of the String type.
Example 6-7 Example: Use of oracle.sql.BLOB Write Routines with BLOB

This example writes data to a BLOB using methods of the oracle.sql.BLOB class.
Input a BLOB and specified length.
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void writeToBlob(BLOB blob, long blobLen) throws SQLException

{
byte[] chunk = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
long chunkLen = (long)chunk.length;
for (long i = 0; i < blobLen; i+= chunkLen) {

if (blobLen < chunkLen) chunkLen = blobLen;
chunk[0] = (byte)(i+1);
chunkLen = blob.putBytes(i, chunk);
}
}
This method goes through a loop that writes to the BLOB in 10-byte chunks until the
specified BLOB length has been reached.
Example 6-8 Example: Use of DBMS_LOB Write Routines with BLOB
This example uses routines of the DBMS_LOB package to write to a BLOB.
void writeToBlob(BLOB blob, long blobLen) throws SQLException
{
byte[] chunk = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
long chunkLen = (long)chunk.length;
for (long i = 1; i <= blobLen; i += chunkLen) {

if ((blobLen - i + 1) < chunkLen) chunkLen = blobLen - i + 1;
chunk[0] = (byte)i;
#sql { CALL dbms_lob.write(:INOUT blob, :chunkLen, :i, :chunk) };
}
}
This method fills the contents of a BLOB in 10-byte chunks. Note that the chunk host
variable is of the byte[] type.
6.3.3 Support for Oracle ROWID

The Oracle specific ROWID type stores the unique address for each row in a database
table. The oracle.sql.ROWID class wraps ROWID information and is used to bind and
define variables of the ROWID type.
Variables of the oracle.sql.ROWID type can be used in SQLJ applications connecting

to Oracle Database 12c Release 2 (12.2) in the following ways:
• As IN, OUT or INOUT host variables in SQLJ executable statements and in INTO-lists
• As a return value from a stored function call
• As column types in iterator declarations
ROWIDs in Iterator Declarations

You can use oracle.sql.ROWID as a column type for SQLJ positional and named
iterators, as shown in the following declarations:
#sql iterator NamedRowidIter (String ename, ROWID rowid);
#sql iterator PositionedRowidIter (String, ROWID);
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ROWID Host Variables and Named-Iterator SELECT Results

You can use ROWID objects as IN, OUT and INOUT parameters in SQLJ executable
statements. In addition, you can populate iterators whose columns include ROWID
types. This code example uses the preceding example declarations.
#sql iterator NamedRowidIter (String ename, ROWID rowid);
...
NamedRowidIter iter;
ROWID rowid;
#sql iter = { SELECT first_name, rowid FROM employees };
while (iter.next())
{
if (iter.first_name().equals("Peter Hall"))
{
rowid = iter.rowid();
#sql { UPDATE employees SET salary = salary + 500 WHERE rowid = :rowid };
}
}
iter.close();
...
This example increases the salary of the employee named Peter Hall by $500
according to the ROWID.
ROWID Stored Function Results

Consider the following function:
CREATE OR REPLACE FUNCTION get_rowid (name VARCHAR2) RETURN ROWID IS
rid ROWID;
BEGIN
SELECT rowid INTO rid FROM employees WHERE first_name = name;
RETURN rid;
END get_rowid;
Given the preceding stored function, the following example indicates how a ROWID
object is used as the assignment type for the function return result:
ROWID rowid;
#sql rowid = { values(get_rowid('AMY FEINER')) };
This example increases the salary of the employee named Amy Feiner by $500
ROWID SELECT INTO Targets

Host variables of the ROWID type can appear in the INTO-list of a SELECT INTO
statement.
ROWID rowid;
#sql { SELECT rowid INTO :rowid FROM employees WHERE first_name='PETER HALL' };
This example increases the salary of the employee named Peter Hall by $500
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ROWID Host Variables and Positional Iterator FETCH INTO Targets

Host variables of the ROWID type can appear in the INTO-list of a FETCH INTO statement
if the corresponding column attribute in the iterator is of the identical type.
#sql iterator PositionedRowidIter (String, ROWID);
...
PositionedRowidIter iter;
ROWID rowid = null;
String ename = null;
#sql iter = { SELECT first_name, rowid FROM employees };
while (true)
{
#sql { FETCH :iter INTO :ename, :rowid };
if (ename.equals("PETER HALL"))
{
}
}
iter.close();
...
This example is similar to the previous named iterator example, but uses a positional
iterator with its customary FETCH INTO syntax.
Positioned Update and Delete

Since Oracle Database 11g Release 1, SQLJ supports positioned update and
delete operations. A positioned update or delete operation can be done using an
iterator. The iterator used for positioned update or delete should implement the
sqlj.runtime.ForUpdate interface. You can use a named iterator, positional iterator,
or scrollable iterator.
The following code illustrates a positioned update:
...
#sql iterator iter implements sqlj.runtime.ForUpdate(String str)
...
#sql iter = {SELECT first_name FROM employees WHERE department_id=10};
...
while(iter.next())
{
#sql {UPDATE employees SET salary=salary+5000 WHERE CURRENT OF :iter};
}
...
In the preceding code, an iterator iter is created and used to update the employees
table.
Note:
If you want to avoid synchronization problems, then issue a SELECT ... FOR
UPDATE statement.
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You can similarly perform a positioned delete. For example:

...
#sql {DELETE FROM employees WHERE CURRENT OF :iter}
...
In the preceding example, iter is an iterator used to perform positioned delete.
The iterators that can be used with the WHERE CURRENT OF clause have the following
limitations:
• The query used to populate the iterator should not operate on multiple tables.
• You cannot use a PL/SQL procedure returning a REF CURSOR with the iterator.
• You cannot use an iterator that has been populated from a result set. That is, an
iterator populated using the following statement, where rs is a result set:
#sql iter = {cast :rs}
for_update Option
If for_update option is set at translation time, then "FOR UPDATE" is appended to the
SELECT statements, which in turn return results into a ForUpdate iterator as follows:
% sqlj –for_update abc.sqlj
/* abc.sqlj */
#sql iterator SalByName (double sal, String ename) implements
sqlj.runtime.ForUpdate;
public class abc {

…..
void func1()
{
SalByName salbn;
#sql salbn = {select salary, first_name from employees };
}
…..
}
Now, "FOR UPDATE" is appended to the SELECT statement returning the ForUpdate
iterator salbn in the following way:
………
String theSqlTS = “SELECT rowid sjT_rowid,first_name, salary FROM employees
WHERE first_name = :1 FOR UPDATE";
………
Table 6-3 shows the plausible values for the for_update option and the corresponding
SQL statement for the preceding example:
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Chapter 6
Table 6-3 Plausible values for the for_update option and the corresponding
SQL statement
for_update option SQLJ Statement SQL Statement

none sqlj -for_update SELECT rowid
abc.sqlj sjT_rowid,first_name,
salary FROM employees
WHERE first_name = :1
FOR UPDATE
nowait sqlj -P- SELECT rowid
for_update=nowait sjT_rowid,first_name,
QueryDemo.sqlj salary FROM employees
FOR UPDATE nowait
number sqlj -P-for_update=10 SELECT rowid
QueryDemo.sqlj sjT_rowid,first_name,
salary FROM employees
FOR UPDATE wait 10
Note:
If the application already has FOR UPDATE in the select query, then using
these new translator options will throw warnings during online check at
translation time. If offline parsing is chosen during translation, then errors
are not detected at translation time.
6.3.4 Support for Oracle REF CURSOR Types

Oracle PL/SQL and the Oracle SQLJ implementation support the use of cursor
variables that represent database cursors.
Overview of REF CURSOR Types

Cursor variables are functionally equivalent to JDBC result sets, essentially
encapsulating the results of a query. A cursor variable is often referred to as a REF
CURSOR, but REF CURSOR itself is a type specifier, and not a type name. Instead,
named REF CURSOR types must be specified. The following example shows a REF
CURSOR type specification:
TYPE EmpCurType IS REF CURSOR;
Stored procedures and stored functions can return parameters of Oracle REF
CURSOR types. You must use PL/SQL to return a REF CURSOR parameter. You
cannot accomplish this using SQL alone. A PL/SQL stored procedure or function can
declare a variable of some named REF CURSOR type, execute a SELECT statement,
and return the results in the REF CURSOR variable.
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Chapter 6
See Also:
Oracle Database PL/SQL Language Reference
REF CURSOR Types in SQLJ

In the Oracle SQLJ implementation, a REF CURSOR type can be mapped to iterator
columns or host variables of any iterator class type or of the java.sql.ResultSet
type, but host variables can be OUT only. Support for REF CURSOR types can be
summarized as follows:
• As result expressions for stored function returns
• As output host expressions for stored procedure or function output parameters
• As output host expressions in INTO-lists
• As iterator columns
You can use the SQL CURSOR operator for a nested SELECT within an outer SELECT
statement. This is how you can write a REF CURSOR object to an iterator column or
ResultSet column in an iterator, or write a REF CURSOR object to an iterator host
variable or ResultSet host variable in an INTO-list.
See Also:
"Using Iterators and Result Sets as Host Variables" for examples illustrating
the use of implicit REF CURSOR variables, including an example of the
CURSOR operator.
Note:
• Use the type code OracleTypes.CURSOR for REF CURSOR types.

• There is no oracle.sql class for REF CURSOR types. Use either
java.sql.ResultSet or an iterator class. Close the result set or iterator
to release resources when you are done processing it.
REF CURSOR Example

The following sample method shows a REF CURSOR type being retrieved from an
anonymous block:
private static EmpIter refCursInAnonBlock(String name, int no)
throws java.sql.SQLException {
EmpIter emps = null;
System.out.println("Using anonymous block for ref cursor..");

#sql { begin
INSERT INTO employees (first_name, employee_id) VALUES (:name, :no);
OPEN :out emps FOR SELECT first_name, employee_id FROM employees
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ORDER BY employee_id;
end
};
return emps;
}
6.3.5 Support for Other Oracle Database 11g Data Types

All oracle.sql classes can be used for iterator columns or for input, output, or input-
output host variables in the same way that any standard Java type can be used. This
includes the classes mentioned in the preceding sections and others, such as the
oracle.sql.NUMBER, oracle.sql.CHAR, and oracle.sql.RAW classes.
Because the oracle.sql.* classes do not require conversion to Java type format,
they offer greater efficiency and precision than equivalent Java types. You would have
to convert the data to standard Java types, however, to use it with standard Java
programs or to display it to end users.
6.3.6 Extended Support for BigDecimal

SQLJ supports java.math.BigDecimal in the following situations:
• As host variables in SQLJ executable statements

• As return values from stored function calls
• As iterator column types
Standard SQLJ has the limitation that a value can be retrieved as BigDecimal only if
that is the JDBC default mapping, which is the case only for numeric and decimal data.
See Also:
Table 6-1
In the Oracle SQLJ implementation, however, you can map to nondefault types as
long as the data type is convertible from numeric and you use Oracle9i Database
or later version, an Oracle JDBC driver, Oracle-specific code generation or Oracle
customizer, and Oracle SQLJ run time. The CHAR, VARCHAR2, LONG, and NUMBER types
are convertible. For example, you can retrieve data from a CHAR column into a
BigDecimal variable. However, to avoid errors, you must be careful that the character
data consists only of numbers.
Note:
The BigDecimal class is in the standard java.math package.
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7
Objects, Collections, and OPAQUE Types
This chapter discusses how the Oracle SQLJ implementation supports user-defined
SQL types. There is also a small section at the end regarding Oracle OPAQUE types.
The chapter consists of the following sections:
• Oracle Objects and Collections
• Custom Java Classes
• User-Defined Types
• Strongly Typed Objects and References in SQLJ Executable Statements
• Strongly Typed Collections in SQLJ Executable Statements
• Serialized Java Objects
• Weakly Typed Objects_ References_ and Collections
• Oracle OPAQUE Types
7.1 Oracle Objects and Collections

This section provides some background conceptual information about Oracle
Database 12c Release 2 (12.2) objects and collections.
See Also:
Oracle Database SQL Language Reference and Oracle Database
Development Guide.

• Overview of Objects and Collections
• Oracle Object Fundamentals
• Oracle Collection Fundamentals
• Object and Collection Data Types
7.1.1 Overview of Objects and Collections

The Oracle SQLJ implementation supports user-defined SQL object types, which
are composite data structures, related SQL object reference types, and user-defined
SQL collection types. Oracle objects and collections are composite data structures
consisting of individual data elements.
The Oracle SQLJ implementation supports either strongly typed or weakly typed
Java representations of object types, reference types, and collection types to use
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Oracle Objects and Collections
in iterators or host expressions. Strongly typed representations use a custom Java

class that maps to a particular object type, reference type, or collection type
and must implement either the Java Database Connectivity (JDBC) 2.0 standard
java.sql.SQLData interface, for object types only, or the Oracle oracle.sql.ORAData
interface.
The term strongly typed is used where a particular Java type is associated with a
particular SQL named type or user-defined type. For example, if there is a PERSON
type, then a corresponding Person Java class will be associated with it.
Weakly typed representations use oracle.sql.STRUCT for objects, oracle.sql.REF

for object references, or oracle.sql.ARRAY for collections. Alternatively, you can use
standard java.sql.Struct, java.sql.Ref, or java.sql.Array objects in a weakly
typed scenario.
The term weakly typed is used where a Java type is used in a generic
way and can map to multiple SQL named types. The Java class or interface
has no special information particular to any SQL type. This is the case for
the oracle.sql.STRUCT, oracle.sql.REF, and oracle.sql.ARRAY types and the
java.sql.Struct, java.sql.Ref, and java.sql.Array types.
Note that using Oracle extensions in your code requires the following:
• Use default Oracle-specific code generation or, for ISO code generation,
customize the profiles appropriately. For Oracle-specific generated code, no
profiles are produced so customization is not applicable. Oracle JDBC application
programming interfaces (APIs) are called directly through the generated Java
code.
Note:
Oracle recommends the use of the default customizer,
oracle.sqlj.runtime.util.OraCustomizer.
• Use Oracle SQLJ run time when your application runs. Oracle SQLJ run time and
an Oracle JDBC driver are required whenever you use Oracle customizer, even if
you do not actually use Oracle extensions in your code.
Note:
Oracle-specific types for Oracle objects and collections are included in the
oracle.sql package.
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Chapter 7
See Also:
"Connection Options" and "Semantics-Checking and Offline-Parsing Options"
Custom Java Class Usage Notes

• This chapter primarily discusses the use of custom Java classes with user-defined
types. However, classes implementing ORAData can be used for other Oracle SQL
types as well. A class implementing ORAData can be used to perform any kind of
desired processing or conversion in the course of transferring data between SQL
and Java.
See Also:
"Additional Uses for ORAData Implementations"
• The SQLData interface is intended only for custom object classes. The ORAData
interface can be used for any custom Java class.
Terminology Notes
• User-defined SQL object types and user-defined SQL collection types are referred
to as user-defined types (UDTs).
• Custom Java classes for objects, references, and collections are referred to as
custom object classes, custom reference classes, and custom collection classes,
respectively.
See Also:
Oracle Database Object-Relational Developer's Guide for general
information about Oracle object features and functionality
7.1.2 Oracle Object Fundamentals

The Oracle SQL objects are composite data structures that group related data items,
such as facts about each employee, into a single data unit. An object type is
functionally similar to a Java class. You can populate and use any number of individual
objects of a given object type, just as you can instantiate and use individual objects of
a Java class.
For example, you can define an object type EMPLOYEE that has the attributes name of
type CHAR, address of type CHAR, phonenumber of type CHAR, and employeenumber of
type NUMBER.
Oracle objects can also have methods, or stored procedures, associated with the
object type. These methods can be either static methods or instance methods and can
be implemented either in PL/SQL or Java. Their signatures can include any number
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of input, output, or input-output parameters. All this depends on how they are initially
defined
7.1.3 Oracle Collection Fundamentals

There are two categories of Oracle SQL collections:
• Variable-length arrays (VARRAY types)
• Nested tables (TABLE types)
Both categories are one-dimensional, although the elements can be complex object
types. VARRAY types are used for one-dimensional arrays, and nested table types are
used for single-column tables within an outer table. A variable of any VARRAY type
can be referred to as a VARRAY. A variable of any nested table type can be referred to
as a nested table.
A VARRAY, as with any array, is an ordered set of data elements, with each element
having an index and all elements being of the same data type. The size of a VARRAY
refers to the maximum number of elements. Oracle VARRAYs, as indicated by their
name, are of variable size, but the maximum size of any particular VARRAY type must
be specified when the VARRAY type is declared.
A nested table is an unordered set of elements. Nested table elements within a table
can themselves be queried in SQL. A nested table, as with any table, is not created
with any particular number of rows. This is determined dynamically.
Note:
The elements in a VARRAY or the rows in a nested table can be of a
user-defined object type, and VARRAY and nested table types can be used
for attributes in a user-defined object type. Oracle Database 12c Release 2
(12.2) supports nesting of collection types. The elements of a VARRAY or
rows of a nested table can be of another VARRAY or nested table type, or
these elements can be of a user-defined object type that has VARRAY or
nested table attributes.
7.1.4 Object and Collection Data Types

In Oracle Database 12c Release 2 (12.2), user-defined object and collection
definitions function as SQL data type definitions. You can use these data types, as
with any other data type, in defining table columns, SQL object attributes, and stored
procedure or function parameters. In addition, once you have defined an object type,
the related object reference type can be used as any other SQL reference type.
For example, consider the EMPLOYEE Oracle object described in the preceding section.
Once you have defined this object, it becomes an Oracle data type. You can have a
table column of type EMPLOYEE just as you can have a table column of type NUMBER.
Each row in an EMPLOYEE column contains a complete EMPLOYEE object. You can also
have a column type of REF EMPLOYEE, consisting of references to EMPLOYEE objects.
Similarly, you can define a variable-length array MYVARR as VARRAY(10) of NUMBER and
a nested table NTBL of CHAR(20). The MYVARR and NTBL collection types become Oracle
data types, and you can have table columns of either type. Each row of a MYVARR
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column consists of an array of up to 10 numbers. Each row of an NTBL column consists

of 20 characters.
7.2 Custom Java Classes

Custom Java classes are first-class types that you can use to read from and write
to user-defined SQL types transparently. The purpose of custom Java classes is to
provide a way to convert data between SQL and Java and make the data accessible,
particularly in supporting objects and collections or if you want to perform custom data
conversions.
It is generally advisable to provide custom Java classes for all user-defined types that
you use in a SQLJ application. Oracle JDBC driver will use instances of these classes
in converting data, which is more convenient and less error-prone than using the
weakly typed oracle.sql.STRUCT, oracle.sql.REF, and oracle.sql.ARRAY classes.
To be used in SQLJ iterators or host expressions, a custom Java class must

implement either the oracle.sql.ORAData and oracle.sql.ORADataFactory interfaces
or the standard java.sql.SQLData interface. This section provides an overview of
these interfaces and custom Java class functionality, covering the following topics:
• Custom Java Class Interface Specifications
• Custom Java Class Support for Object Methods
• Custom Java Class Requirements
• Compiling Custom Java Classes
• Reading and Writing Custom Data
• Additional Uses for ORAData Implementations
7.2.1 Custom Java Class Interface Specifications

This section discusses specifications of the ORAData and ORADataFactory interfaces
and the standard SQLData interface.
Oracle Database 12c Release 2 (12.2) includes a set of APIs for Oracle-specific
custom Java class functionality for user-defined types: oracle.sql.ORAData and
oracle.sql.ORADataFactory.
ORAData and ORADataFactory Specifications

Oracle provides the oracle.sql.ORAData interface and the related
oracle.sql.ORADataFactory interface to use in mapping and converting Oracle object
types, reference types, and collection types to custom Java classes.
Data is sent or retrieved in the form of an oracle.sql.Datum object, with
the underlying data being in the format of the appropriate oracle.sql.Datum
subclass, such as oracle.sql.STRUCT. This data is still in its SQL format. The
oracle.sql.Datum object is just a wrapper.
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See Also:
The ORAData interface specifies a toDatum() method for data conversion from Java
format to SQL format. This method takes as input your connection object and
converts data to the appropriate oracle.sql.* representation. The connection object
is necessary so that the JDBC driver can perform appropriate type checking and type
conversions at run time. The ORAData and toDatum() specification is as follows:
interface oracle.sql.ORAData
{
oracle.sql.Datum toDatum(java.sql.Connection c) throws SQLException;
}
The ORADataFactory interface specifies a create() method that constructs instances

of your custom Java class, converting from SQL format to Java format. This method
takes as input a Datum object containing the data and a type code, such as
OracleTypes.RAW, indicating the SQL type of the underlying data. It returns an object
of your custom Java class, which implements the ORAData interface. This object
receives its data from the Datum object that was input. The ORADataFactory and
create() specification is as follows:
interface oracle.sql.ORADataFactory
{
oracle.sql.ORAData create(oracle.sql.Datum d, int sqlType)
throws SQLException;
}
To complete the relationship between the ORAData and ORADataFactory interfaces, you
must implement a static getORADataFactory() method in any custom Java class that
implements the ORAData interface. This method returns an object that implements the
ORADataFactory interface and that, therefore, can be used to create instances of your
custom Java class. This returned object can itself be an instance of your custom Java
class, and its create() method is used by Oracle JDBC driver to produce further
instances of your custom Java class, as necessary.
SQLData Specification
Standard JDBC 2.0 supplies the java.sql.SQLData interface to use in mapping and
converting structured object types to Java classes. This interface is intended for
mapping structured object types only, not object references, collections or arrays, or
other SQL types.
The SQLData interface is a JDBC 2.0 standard, specifying a readSQL() method to read
data into a Java object and a writeSQL() method to write to the database from a Java
object.
For additional information about standard SQLData functionality, refer to the Sun
Microsystems JDBC 2.0 or later API specification.
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7.2.2 Custom Java Class Support for Object Methods

Methods of Oracle objects can be invoked from custom Java class wrappers. Whether
the underlying stored procedure is written in PL/SQL or is written in Java and
published to SQL is invisible to the user.
A Java wrapper method used to invoke a server method requires a connection to
communicate with the server. The connection object can be provided as an explicit
parameter or can be associated in some other way. For example, as an attribute
of your custom Java class. If the connection object used by the wrapper method is
a nonstatic attribute, then the wrapper method must be an instance method of the
custom Java class in order to have access to the connection.
There are also issues regarding output and input-output parameters in methods of
Oracle objects. If a stored procedure, that is, a SQL object method, modifies the
internal state of one of its arguments, then the actual argument passed to the stored
procedure is modified. In Java this is not possible. When a JDBC output parameter is
returned from a stored procedure call, it must be stored in a newly created object. The
original object identity is lost.
One way to return an output or input-output parameter to the caller is to pass the
parameter as an element of an array. If the parameter is input-output, then the wrapper
method takes the array element as input. After processing, the wrapper assigns the
output to the array element.
7.2.3 Custom Java Class Requirements

Custom Java classes must satisfy certain requirements to be recognized by Oracle
SQLJ translator as valid host variable types and to enable type-checking by the
translator.
Note:
Custom Java classes for user-defined types are often referred to in this
manual as "wrapper classes".
Oracle Requirements for Classes Implementing ORAData

Oracle requirements for ORAData implementations are primarily the same for any kind
of custom Java class, but vary slightly depending on whether the class is for mapping
to objects, object references, collections, or some other SQL type.
These requirements are as follows:
• The class implements the oracle.sql.ORAData interface.
• The class implements the getORADataFactory() method that returns an
oracle.sql.ORADataFactory object. The method signature is as follows:
public static oracle.sql.ORADataFactory getORADataFactory();
• The class has a String constant, _SQL_TYPECODE, initialized to the
oracle.jdbc.OracleTypes type code of the Datum subclass instance that
toDatum() returns. The type code is:
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– For custom object classes:

public static final int _SQL_TYPECODE = OracleTypes.STRUCT;
– For custom reference classes:
public static final int _SQL_TYPECODE = OracleTypes.REF;
– For custom collection classes:
public static final int _SQL_TYPECODE = OracleTypes.ARRAY;
For other uses, some other type code might be appropriate. For example, for using
a custom Java class to serialize and deserialize Java objects into or out of RAW
fields, a _SQL_TYPECODE of OracleTypes.RAW is used.
Note:
The OracleTypes class simply defines a type code, which is an
integer constant, for each Oracle data type. For standard SQL types,
the OracleTypes entry is identical to the entry in the standard
java.sql.Types type definitions class.
See Also:
"Serialized Java Objects"
• For custom Java classes with _SQL_TYPECODE of STRUCT, REF, or ARRAY, that is, for
custom Java classes that represent objects, object references, or collections, the
class has a constant that indicates the relevant user-defined type name. This is as
follows:
– Custom object classes and custom collection classes must have a String
constant, _SQL_NAME, initialized to the SQL name you declared for the user-
defined type, as follows:
public static final String _SQL_NAME = UDT name;
For example, the custom object class for a user-defined PERSON object will
have the constant:
public static final String _SQL_NAME = "PERSON";
The same can be specified along with the schema, if appropriate, as follows:
public static final String _SQL_NAME = "HR.PERSON";
The custom collection class for a collection of PERSON objects, which you have
declared as PERSON_ARRAY, will have the constant:
public static final String _SQL_NAME = "PERSON_ARRAY";
– Custom reference classes must have a String constant, _SQL_BASETYPE,
initialized to the SQL name you declared for the user-defined type being
referenced, as follows:
public static final String _SQL_BASETYPE = UDT name;
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The custom reference class for PERSON references will have the constant:
public static final String _SQL_BASETYPE = "PERSON";
For other ORAData uses, specifying a UDT name is not applicable.

Keep in mind the following usage notes:
• A collection type name reflects the collection type, not the base type. For example,
if you have declared a VARRAY or nested table type, PERSON_ARRAY, for PERSON
objects, then the name of the collection type that you specify for the _SQL_NAME
entry is PERSON_ARRAY, not PERSON.
• When specifying the SQL type in a _SQL_NAME field, if the SQL type was declared
in a case-sensitive way (in quotes), then you must specify the SQL name exactly
as it was declared, such as CaseSensitive or HR.CaseSensitive.
Requirements for Classes Implementing SQLData

The ISO SQLJ standard outlines requirements for type map definitions for classes
implementing the SQLData interface. Alternatively, SQLData wrapper classes can
identify associated SQL object types through the public static final fields.
Be aware of the following important points:

• Whether you use a type map or use alternative (nonstandard) public static
final fields to specify mappings, you must be consistent in your approach. Either
use a type map that specifies all relevant mappings so that you do not require
the public static final fields, or do not use a type map at all and specify all
mappings through the public static final fields.
• SQLData, unlike ORAData, is for mapping structured object types only. It is not
for object references, collections or arrays, or any other SQL types. If you are
not using ORAData, then your only choices for mapping object references and
collections are the weak java.sql.Ref and java.sql.Array types, respectively, or
oracle.sql.REF and oracle.sql.ARRAY.
• SQLData implementations require a Java Development Kit (JDK) 1.4.x or 1.5.x
environment.
• When specifying the mapping from a SQL type to a Java type, if the SQL type was
declared in a case-sensitive way, then you must specify the SQL name exactly as
it was declared, such as CaseSensitive or HR.CaseSensitive.
Mapping Specified in Type Map Resource

First, consider the mapping representation according to the ISO SQLJ standard.
Assume that Address, pack.Person, and pack.Manager.InnerPM, where InnerPM is an
inner class of Manager, are three wrapper classes that implement java.sql.SQLData.
Then, you need to consider the following:

• You must use these classes only in statements that use explicit connection context
instances of a declared connection context type. For example, assuming that this
type is called SDContext:
Address a =...;
pack.Person p =...;
pack.Manager.InnerPM pm =...;
SDContext ctx = new SDContext(url,user,pwd,false);
#sql [ctx] { ... :a ... :p ... :pm ... };
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• The connection context type must have been declared using the
with attribute typeMap that specifies an associated class implementing
java.util.PropertyResourceBundle. In the preceding example, SDContext may
be declared as follows:
#sql public static context SDContext with (typeMap="SDMap");
• The type map resource must provide the mapping from SQL object types to
corresponding Java classes that implement the java.sql.SQLData interface. This
mapping is specified with entries of the following form:
class.java_class_name=STRUCT sql_type_name
The STRUCT keyword can also be omitted. In the example, the SDMap.properties
resource file may contain the following entries:
class.Address=STRUCT HR.ADDRESS
class.pack.Person=PERSON
class.pack.Manager$InnerPM=STRUCT PRODUCT_MANAGER
Although the period (.) separates package and class name, you must use the
dollar sign ($) to separate an inner class name.
Note:
If you used the default Oracle-specific code generation in this example, then
any iterator that is used for a statement whose context type is SDContext
must also have been declared with the same associated type map, SDMap,
such as in the following example:
#sql public static iterator SDIter with (typeMap="SDMap");
...
SDContext sdctx = ...
SDIter sditer;
#sql [sdctx] sditer = { SELECT ...};
This is to ensure that proper code is generated for the iterator class.
This mechanism of specifying mappings in a type map resource is more complicated

than the nonstandard alternative. Also, it is not possible to associate a type map
resource with the default connection context. The advantage is that all the mapping
information is placed in a single location, the type map resource. This means that the
type mapping in an already compiled application can be easily adjusted at a later time,
for example, to accommodate new SQL types and Java wrappers in an expanding
SQL-Java type hierarchy.
• You must employ the SQLJ runtime12 or runtime12ee library to use this feature.
Type maps are represented as java.util.Map objects. These are exposed in the
SQLJ run-time API and, therefore, cannot be supported by the generic run-time
library.
• You must use Oracle SQLJ run time and Oracle-specific code generation or profile
customization if your SQLData wrapper classes occur as OUT or INOUT parameters
in SQLJ statements. This is because the SQL type of such parameters is required
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for registerOutParameter() by Oracle JDBC driver. Also, for OUT parameter type
registration, the SQL type is "frozen in" by the type map in effect during translation.
• The SQLJ type map is independent of any JDBC type map you may be using on
the underlying connection. Thus, you must be careful when you are mixing SQLJ
and JDBC code if both use SQLData wrappers. However, you can easily extract the
type map in effect on a given SQLJ connection context:
ctx.getTypeMap();
Mapping Specified in Static Field of Wrapper Class

A class that implements SQLData can satisfy the following nonstandard requirement:
• The Java class declares the String constant _SQL_NAME, which defines the name
of the SQL type that is being wrapped by the Java class. In the example, the
Address class would have the following field declaration:
public static final String _SQL_NAME="HR.ADDRESS";
The following declaration would be in pack.Person:

public static final String _SQL_NAME="PERSON";
And the pack.Manager.InnerPM class would have the following:

public static final String _SQL_NAME="PRODUCT_MANAGER";
Note:
• If a class that implements the _SQL_NAME field is used in a SQLJ

statement with an explicit connection context type and associated type
map, then that type map is used and the _SQL_NAME field is ignored.
This simplifies migration of existing SQLJ programs to the ISO SQLJ
standard.
• The static SQL-Java type correspondence specified in the _SQL_NAME
field is independent from any JDBC type map you may be using on the
underlying connection. Thus, you must be careful when you are mixing
SQLJ and JDBC code if both use SQLData wrappers.
7.2.4 Compiling Custom Java Classes

You can include any .java files for your custom Java classes, whether ORAData or
SQLData implementations, on the SQLJ command line together with the .sqlj files for
your application. However, this is not necessary if the SQLJ -checksource flag is set to
true, which is the default, and your classpath includes the directory where the custom
Java source is located.
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Note:
This discussion assumes you are creating .java files for your custom objects
and collections, not .sqlj files. Any .sqlj files must be included in the SQLJ
command line.
For example, if ObjectDemo.sqlj uses the ADDRESS and PERSON Oracle object types
and you have produced custom Java classes for these objects, then you can run SQLJ
as follows.
• If -checksource=true and the classpath includes the custom Java source location:
% sqlj ObjectDemo.sqlj
• If -checksource=false (this is a single wraparound line):
% sqlj ObjectDemo.sqlj Address.java AddressRef.java Person.java
PersonRef.java
You also have the choice of using your Java compiler to compile custom .java source
files directly. If you do this, then you must do it prior to translating .sqlj files.
Note:
Because ORAData implementations rely on Oracle-specific features, SQLJ will
report numerous portability warnings if you do not use the -warn=noportable
translator portability setting, which is the default.
7.2.5 Reading and Writing Custom Data

Through the use of custom Java class instances, the Oracle SQLJ and JDBC
implementations allow you to read and write user-defined types as though they are
built-in types. Exactly how this is accomplished is transparent to the user.
For the mechanics of how data is read and written, for both ORAData implementations
and SQLData implementations, refer to the Oracle Database JDBC Developer's Guide.
7.2.6 Additional Uses for ORAData Implementations

To this point, discussion of custom Java classes has been for use as one of the
following.
• Wrappers for SQL objects: custom object classes, for use with oracle.sql.STRUCT
instances
• Wrappers for SQL references: custom reference classes, for use with
oracle.sql.REF instances
• Wrappers for SQL collections: custom collection classes, for use with
oracle.sql.ARRAY instances
It might be useful, however, to provide custom Java classes to wrap other
oracle.sql.* types as well, for customized conversions or processing. You can
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accomplish this with classes that implement ORAData, but not SQLData, as in the
following examples:
• Perform encryption and decryption or validation of data.
• Perform logging of values that have been read or are being written.
• Parse character columns, such as character fields containing URL information,
into smaller components.
• Map character strings into numeric constants.
• Map data into more desirable Java formats, such as mapping a DATE field to
java.util.Date format.
• Customize data representation, for example, data in a table column is in feet, but
you want it represented in meters after it is selected.
• Serialize and deserialize Java objects, for example, into or out of RAW fields.
Note:
This sort of functionality is not possible through the SQLData interface, as
SQLData implementations can wrap only structured object types.
See Also:
"Serialized Java Objects"
General Use of ORAData: BetterDate.java

This example shows a class that implements the ORAData interface to provide a
customized representation of Java dates and can be used instead of java.sql.Date.
Note:
This is not a complete application. There is no main() method.
import java.util.Date;
import oracle.sql.ORAData;
import oracle.sql.DATE;
import oracle.sql.ORADataFactory;
import oracle.jdbc.OracleTypes;
// a Date class customized for user's preferences:

// - months are numbers 1..12, not 0..11
// - years are referred to through four-digit numbers, not two.
public class BetterDate extends java.util.Date

implements ORAData, ORADataFactory {
public static final int _SQL_TYPECODE = OracleTypes.DATE;
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String[]monthNames={"JAN", "FEB", "MAR", "APR", "MAY", "JUN",

"JUL", "AUG", "SEP", "OCT", "NOV", "DEC"};
String[]toDigit={"0", "1", "2", "3", "4", "5", "6", "7", "8", "9"};
static final BetterDate _BetterDateFactory = new BetterDate();
public static ORADataFactory getORADataFactory() { return _BetterDateFactory;}
// the current time...

public BetterDate() {
super();
}
public oracle.sql.Datum toDatum(java.sql.Connection conn) {

return new DATE(toSQLDate());
}
public oracle.sql.ORAData create(oracle.sql.Datum dat, int intx) {

if (dat==null) return null;
DATE DAT = ((DATE)dat);
java.sql.Date jsd = DAT.dateValue();
return new BetterDate(jsd);
}
public java.sql.Date toSQLDate() {

java.sql.Date retval;
retval = new java.sql.Date(this.getYear()-1900, this.getMonth()-1,
this.getDate());
return retval;
}
public BetterDate(java.sql.Date d) {
this(d.getYear()+1900, d.getMonth()+1, d.getDate());
}
private static int [] deconstructString(String s) {
int [] retval = new int[3];
int y,m,d; char temp; int offset;
StringBuffer sb = new StringBuffer(s);
temp=sb.charAt(1);
// figure the day of month
if (temp < '0' || temp > '9') {
m = sb.charAt(0)-'0';
offset=2;
} else {
m = (sb.charAt(0)-'0')*10 + (temp-'0');
offset=3;
}
// figure the month

temp = sb.charAt(offset+1);
if (temp < '0' || temp > '9') {
d = sb.charAt(offset)-'0';
offset+=2;
} else {
d = (sb.charAt(offset)-'0')*10 + (temp-'0');
offset+=3;
}
// figure the year, which is either in the format "yy" or "yyyy"

// (the former assumes the current century)
if (sb.length() <= (offset+2)) {
y = (((new BetterDate()).getYear())/100)*100 +
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(sb.charAt(offset)- '0') * 10 +
(sb.charAt(offset+1)- '0');
} else {
y = (sb.charAt(offset)- '0') * 1000 +
(sb.charAt(offset+1)- '0') * 100 +
(sb.charAt(offset+2)- '0') * 10 +
(sb.charAt(offset+3)- '0');
}
retval[0]=y;
retval[1]=m;
retval[2]=d;
// System.out.println("Constructing date from string as: "+d+"/"+m+"/"+y);
return retval;
}
private BetterDate(int [] stuff) {
this(stuff[0], stuff[1], stuff[2]);
}
// takes a string in the format: "mm-dd-yyyy" or "mm/dd/yyyy" or
// "mm-dd-yy" or "mm/dd/yy" (which assumes the current century)
public BetterDate(String s) {
this(BetterDate.deconstructString(s));
}
// years are as '1990', months from 1..12 (unlike java.util.Date!), date

// as '1' to '31'
public BetterDate(int year, int months, int date) {
super(year-1900,months-1,date);
}
// returns "Date: dd-mon-yyyy"
public String toString() {
int yr = getYear();
return getDate()+"-"+monthNames[getMonth()-1]+"-"+
toDigit[(yr/1000)%10] +
toDigit[(yr/100)%10] +
toDigit[(yr/10)%10] +
toDigit[yr%10];
// return "Date: " + getDate() + "-"+getMonth()+"-"+(getYear()%100);
}
public BetterDate addDays(int i) {
if (i==0) return this;
return new BetterDate(getYear(), getMonth(), getDate()+i);
}
public BetterDate addMonths(int i) {
if (i==0) return this;
int yr=getYear();
int mon=getMonth()+i;
int dat=getDate();
while(mon<1) {
--yr;mon+=12;
}
return new BetterDate(yr, mon,dat);
}
// returns year as in 1996, 2007
public int getYear() {
return super.getYear()+1900;
}
// returns month as 1..12
public int getMonth() {
return super.getMonth()+1;
}
public boolean equals(BetterDate sd) {
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return (sd.getDate() == this.getDate() &&

sd.getMonth() == this.getMonth() &&
sd.getYear() == this.getYear());
}
// subtract the two dates; return the answer in whole years
// uses the average length of a year, which is 365 days plus
// a leap year every 4, except 100, except 400 years =
// = 365 97/400 = 365.2425 days = 31,556,952 seconds
public double minusInYears(BetterDate sd) {
// the year (as defined in the preceding text) in milliseconds
long yearInMillis = 31556952L;
long diff = myUTC()-sd.myUTC();
return (((double)diff/(double)yearInMillis)/1000.0);
}
public long myUTC() {
return Date.UTC(getYear()-1900, getMonth()-1, getDate(),0,0,0);
}
// returns <0 if this is earlier than sd

// returns = if this == sd
// else returns >0
public int compare(BetterDate sd) {
if (getYear()!=sd.getYear()) {return getYear()-sd.getYear();}
if (getMonth()!=sd.getMonth()) {return getMonth()-sd.getMonth();}
return getDate()-sd.getDate();
}
}
7.3 User-Defined Types

This section contains examples of creating and using user-defined object types and
collection types in Oracle Database 12c Release 2 (12.2).
Creating Object Types

SQL commands to create object types are of the following form:
CREATE TYPE typename AS OBJECT
(
attrname1 datatype1,
attrname2 datatype2,
... ...
attrnameN datatypeN
);
Where typename is the desired name of your object type, attrname1 through
attrnameN are the desired attribute names, and datatype1 through datatypeN are
the attribute data types.
The remainder of this section provides an example of creating user-defined object
types in Oracle Database 12c Release 1 (12.1).
In this example, the following items are created using SQL:
• Two object types, PERSON and ADDRESS
• A typed table for PERSON objects
• An EMPLOYEES table that includes an ADDRESS column and two columns of PERSON
references
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User-Defined Types
The script for creating these items is as follows:

/*** Using user-defined types (UDTs) in SQLJ ***/
/
/*** Create ADDRESS UDT ***/
CREATE TYPE ADDRESS AS OBJECT
(
street VARCHAR(60),
city VARCHAR(30),
state CHAR(2),
zip_code CHAR(5)
)
/
/*** Create PERSON UDT containing an embedded ADDRESS UDT ***/
CREATE TYPE PERSON AS OBJECT
(
name VARCHAR(30),
ssn NUMBER,
addr ADDRESS
)
/
/*** Create a typed table for PERSON objects ***/
CREATE TABLE persons OF PERSON
/
/*** Create a relational table with two columns that are REFs
to PERSON objects, as well as a column which is an Address ADT. ***/
CREATE TABLE employees
(
empnumber INTEGER PRIMARY KEY,
person_data REF PERSON,
manager REF PERSON,
office_addr ADDRESS,
salary NUMBER
)
/*** Insert some data--2 objects into the persons typed table ***/
INSERT INTO persons VALUES (
PERSON('Wolfgang Amadeus Mozart', 123456,
ADDRESS('Am Berg 100', 'Salzburg', 'AT','10424')))
/
INSERT INTO persons VALUES (
PERSON('Ludwig van Beethoven', 234567,
ADDRESS('Rheinallee', 'Bonn', 'DE', '69234')))
/
/** Put a row in the employees table **/
INSERT INTO employees (empnumber, office_addr, salary) VALUES (
1001,
ADDRESS('500 Oracle Parkway', 'Redwood Shores', 'CA', '94065'),
50000)
/
/** Set the manager and PERSON REFs for the employee **/
UPDATE employees
SET manager =
(SELECT REF(p) FROM persons p WHERE p.name = 'Wolfgang Amadeus Mozart')
/
UPDATE employees
SET person_data =
(SELECT REF(p) FROM persons p WHERE p.name = 'Ludwig van Beethoven')
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User-Defined Types
Note:
Use of a table alias, such as p in the example, is a recommended general
practice in the Oracle SQL implementation, especially in accessing tables
with user-defined types. It is required syntax in some cases where object
attributes are accessed. Even when not required, it helps in avoiding
ambiguities. Refer to the Oracle Database SQL Language Reference for
more information about table aliases.
Creating Collection Types

There are two categories of collections
• Variable-length arrays (VARRAYs)
• Nested tables
SQL commands to create VARRAY types are of the following form:
CREATE TYPE typename IS VARRAY(n) OF datatype;
The typename designation is the desired name of your VARRAY type, n is the desired
maximum number of elements in the array, and datatype is the data type of the array
elements. For example:
CREATE TYPE myvarr IS VARRAY(10) OF INTEGER;
SQL commands to create nested table types are of the following form:
CREATE TYPE typename AS TABLE OF datatype;
The typename designation is the desired name of your nested table type and datatype
is the data type of the table elements. This can be a user-defined type as well as a
standard data type. A nested table is limited to one column, although that one column
type can be a complex object with multiple attributes. The nested table, as with any
database table, can have any number of rows. For example:
CREATE TYPE person_array AS TABLE OF person;
This command creates a nested table where each row consists of a PERSON object.
The rest of this section provides an example of creating a user-defined collection type,
as well as object types, in Oracle Database 12c Release 2 (12.2).
The following items are created and populated using SQL:
• Two object types, PARTICIPANT_T and MODULE_T
• A collection type, MODULETBL_T, which is a nested table of MODULE_T objects
• A PROJECTS table that includes a column of PARTICIPANT_T references and a
column of MODULETBL_T nested tables
• A collection type PHONE_ARRAY, which is a VARRAY of VARCHAR2(30)
• PERSON and ADDRESS objects (repeating the same definitions used earlier)
• An EMPLOYEES table, which includes a PHONE_ARRAY column
The script for creating these items is as follows:
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Chapter 7
User-Defined Types
Rem This is a SQL*Plus script used to create schema to demonstrate collection

Rem manipulation in SQLJ
CREATE TYPE PARTICIPANT_T AS OBJECT (

empno NUMBER(4),
ename VARCHAR2(20),
job VARCHAR2(12),
mgr NUMBER(4),
hiredate DATE,
sal NUMBER(7,2),
deptno NUMBER(2))
/
SHOW ERRORS
CREATE TYPE MODULE_T AS OBJECT (
module_id NUMBER(4),
module_name VARCHAR2(20),
module_owner REF PARTICIPANT_T,
module_start_date DATE,
module_duration NUMBER )
/
SHOW ERRORS
CREATE TYPE MODULETBL_T AS TABLE OF MODULE_T;
/
SHOW ERRORS
CREATE TABLE projects (
id NUMBER(4),
name VARCHAR(30),
owner REF PARTICIPANT_T,
start_date DATE,
duration NUMBER(3),
modules MODULETBL_T ) NESTED TABLE modules STORE AS modules_tab;
SHOW ERRORS
CREATE TYPE PHONE_ARRAY IS VARRAY (10) OF varchar2(30)
/

(
street VARCHAR(60),
city VARCHAR(30),
state CHAR(2),
zip_code CHAR(5)
)
/
(
name VARCHAR(30),
ssn NUMBER,
addr ADDRESS
)
/
( empnumber INTEGER PRIMARY KEY,
person_data REF person,
manager REF person,
office_addr address,
salary NUMBER,
phone_nums phone_array
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Chapter 7
Strongly Typed Objects and References in SQLJ Executable Statements
)
/
7.4 Strongly Typed Objects and References in SQLJ

Executable Statements
The Oracle SQLJ implementation is flexible in how it enables you to use host
expressions and iterators in reading or writing object data through strongly typed
objects or references.
For iterators, you can use custom object classes as iterator column types.
Alternatively, you can have iterator columns that correspond to individual object
attributes, similar to extent tables, using column types that appropriately map to the
SQL data types of the attributes.
For host expressions, you can use host variables of your custom object class type or
custom reference class type. Alternatively, you can use host variables that correspond
to object attributes, using variable types that appropriately map to the SQL data types
of the attributes.
The remainder of this section provides examples of how to manipulate Oracle objects
using custom object classes, custom object class attributes, and custom reference
classes for host variables and iterator columns in SQLJ executable statements.
The following two examples operate at the object level:
• Selecting Objects and Object References into Iterator Columns
• Updating an Object
The Inserting an Object Created from Individual Object Attributes example operates at
the scalar-attribute level.
The Updating an Object Reference example operates through a reference.
7.4.1 Selecting Objects and Object References into Iterator Columns

This example uses a custom Java class and a custom reference class as iterator
column types. Presume the following definition of the ADDRESS Oracle object type:
( street VARCHAR(40),
zip NUMBER );
And the following definition of the EMPADDRS table, which includes an ADDRESS column
and an ADDRESS reference column:
CREATE TABLE empaddrs
( name VARCHAR(60),
home ADDRESS,
loc REF ADDRESS );
Once you create a custom Java class, Address, and custom reference class,
AddressRef, corresponding to the ADDRESS Oracle object type, you can use Address
and AddressRef in a named iterator as follows:
#sql iterator EmpIter (String name, Address home, AddressRef loc);
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...
EmpIter ecur;
#sql ecur = { SELECT name, home, loc FROM empaddrs };
while (ecur.next()) {
Address homeAddr = ecur.home();
// Print out the home address.
System.out.println ("Name: " + ecur.name() + "\n" +
"Home address: " + homeAddr.getStreet() + " " +
homeAddr.getZip());
// Now update the loc address zip code through the address reference.
AddressRef homeRef = ecur.loc();
Address location = homeRef.getValue();
location.setZip(new BigDecimal(98765));
homeRef.setValue(location);
}
...
The ecur.home() method call extracts an Address object from the home column of the
iterator and assigns it to the homeAddr local variable (for efficiency). The attributes of
that object can then be accessed using standard Java dot syntax:
homeAddr.getStreet()
Use the getValue() and setValue() methods to manipulate the location address (in
this case its zip code).
7.4.2 Updating an Object

This example declares and sets an input host variable of the Address Java type to
update an ADDRESS object in a column of the employees table. Both before and after
the update, the address is selected into an output host variable of the Address type
and printed for verification.
...
// Updating an object
static void updateObject()

{
Address addr;
Address new_addr;
int empnum = 1001;
try {
#sql {
SELECT office_addr
INTO :addr
FROM employees
WHERE empnumber = :empnum };
System.out.println("Current office address of employee 1001:");
printAddressDetails(addr);
/* Now update the street of address */
String street ="100 Oracle Parkway";

addr.setStreet(street);
/* Put updated object back into the database */
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Chapter 7
try {
#sql {
UPDATE employees
SET office_addr = :addr
System.out.println
("Updated employee 1001 to new address at Oracle Parkway.");
/* Select new address to verify update */
try {
#sql {
SELECT office_addr
INTO :new_addr
FROM employees
System.out.println("New office address of employee 1001:");

printAddressDetails(new_addr);
} catch (SQLException exn) {

System.out.println("Verification SELECT failed with "+exn); }

System.out.println("UPDATE failed with "+exn); }

System.out.println("SELECT failed with "+exn); }
}
...
Note the use of the setStreet() accessor method of the Address object.
This example uses the printAddressDetails() utility. The source code for this
method is as follows:
static void printAddressDetails(Address a) throws SQLException
{
if (a == null) {
System.out.println("No Address available.");
return;
}
String street = ((a.getStreet()==null) ? "NULL street" : a.getStreet()) ;

String city = (a.getCity()==null) ? "NULL city" : a.getCity();
String state = (a.getState()==null) ? "NULL state" : a.getState();
String zip_code = (a.getZipCode()==null) ? "NULL zip" : a.getZipCode();
System.out.println("Street: '" + street + "'");

System.out.println("City: '" + city + "'");
System.out.println("State: '" + state + "'");
System.out.println("Zip: '" + zip_code + "'" );
}
7.4.3 Inserting an Object Created from Individual Object Attributes

This example declares and sets input host variables corresponding to attributes of
PERSON and nested ADDRESS objects, then uses these values to insert a new PERSON
object into the persons table in the database.
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...
// Inserting an object
static void insertObject()

{
String new_name = "NEW PERSON";
int new_ssn = 987654;
String new_street = "NEW STREET";
String new_city = "NEW CITY";
String new_state = "NS";
String new_zip = "NZIP";
/*
* Insert a new PERSON object into the persons table
*/
try {
#sql {
INSERT INTO persons
VALUES (PERSON(:new_name, :new_ssn,
ADDRESS(:new_street, :new_city, :new_state, :new_zip))) };
System.out.println("Inserted PERSON object NEW PERSON.");
} catch (SQLException exn) { System.out.println("INSERT failed with "+exn); }

}
...
7.4.4 Updating an Object Reference

This example selects a PERSON reference from the persons table and uses it to update
a PERSON reference in the employees table. It uses simple input host variables to check
attribute value criteria. The newly updated reference is then used in selecting the
PERSON object to which it refers, so that information can be output to the user to verify
the change.
...
// Updating a REF to an object
static void updateRef()

{
int empnum = 1001;
String new_manager = "NEW PERSON";
System.out.println("Updating manager REF.");

try {
#sql {
UPDATE employees
SET manager =
(SELECT REF(p) FROM persons p WHERE p.name = :new_manager)
System.out.println("Updated manager of employee 1001. Selecting back");

System.out.println("UPDATE REF failed with "+exn); }
/* Select manager back to verify the update */

Person manager;
try {
#sql {
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Chapter 7
Strongly Typed Collections in SQLJ Executable Statements
SELECT deref(manager)
INTO :manager
FROM employees e
System.out.println("Current manager of "+empnum+":");

printPersonDetails(manager);

System.out.println("SELECT REF failed with "+exn); }
}
...
Note:
This example uses table alias syntax (p) as discussed previously. Also, the
REF syntax is required in selecting a reference through the object to which
it refers, and the DEREF syntax is required in selecting an object through a
reference. Refer to the Oracle Database SQL Language Reference for more
information about table aliases, REF, and DEREF.
7.5 Strongly Typed Collections in SQLJ Executable

Statements
As with strongly typed objects and references, the Oracle SQLJ implementation
supports different scenarios for reading and writing data through strongly typed
collections, using either iterators or host expressions.
From the perspective of a SQLJ developer, both categories of collections, VARRAY
and nested table, are treated essentially the same, but there are some differences in
implementation and performance.
The Oracle SQLJ implementation supports syntax choices so that nested tables can
be accessed and manipulated either apart from or together with their outer tables. In
this section, manipulation of a nested table by itself will be referred to as detail-level
manipulation and manipulation of a nested table together with its outer table will be
referred to as master-level manipulation.
Most of this section, after a brief discussion of some syntax, focuses on examples of
manipulating nested tables, given that their use is somewhat more complicated than
that of VARRAYs.
Note:
In the Oracle SQLJ implementation, VARRAY types and nested table types
can be retrieved only in their entirety. This is as opposed to the Oracle SQL
implementation, where nested tables can be selectively queried.
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Chapter 7
• Accessing Nested Tables: TABLE syntax and CURSOR syntax

• Inserting a Row that Includes a Nested Table
• Selecting a Nested Table into a Host Expression
• Manipulating a Nested Table Using TABLE Syntax
• Selecting Data from a Nested Table Using a Nested Iterator
• Selecting a VARRAY into a Host Expression
• Inserting a Row that Includes a VARRAY
7.5.1 Accessing Nested Tables: TABLE syntax and CURSOR syntax

The Oracle SQLJ implementation supports the use of nested iterators to access
data in nested tables. Use the CURSOR keyword in the outer SELECT statement to
encapsulate the inner SELECT statement. This is shown in "Selecting Data from a
Nested Table Using a Nested Iterator".
Oracle also supports use of the TABLE keyword to manipulate the individual rows of
a nested table. This keyword informs Oracle that the column value returned by a
subquery is a nested table, as opposed to a scalar value. You must prefix the TABLE
keyword to a subquery that returns a single column value or an expression that yields
a nested table.
The following example shows the use of the TABLE syntax:
UPDATE TABLE(SELECT a.modules FROM projects a WHERE a.id=555) b
SET module_owner=
(SELECT ref(p) FROM employees p WHERE p.ename= 'Smith')
WHERE b.module_name = 'Zebra';
When you see TABLE used as it is here, realize that it is referring to a single nested
table that has been selected from a column of an outer table.
Note:
This example uses table alias syntax (a for projects, b for the nested table,
and p for employees) as discussed previously.
7.5.2 Inserting a Row that Includes a Nested Table

This example shows an operation that manipulates the master level (outer table) and
detail level (nested tables) simultaneously and explicitly. This inserts a row in the
projects table, where each row includes a nested table of the MODULETBL_T type,
which contains rows of MODULE_T objects.
First, the scalar values are set (id, name, start_date, duration), then the nested table
values are set. This involves an extra level of abstraction, because the nested table
elements are objects with multiple attributes. In setting the nested table values, each
attribute value must be set for each MODULE_T object in the nested table. Finally, the
owner values, initially set to null, are set in a separate statement.
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Chapter 7
// Insert Nested table details along with master details
public static void insertProject2(int id) throws Exception

{
System.out.println("Inserting Project with Nested Table details..");
try {
#sql { INSERT INTO Projects(id,name,owner,start_date,duration, modules)
VALUES ( 600, 'Ruby', null, '10-MAY-98', 300,
moduletbl_t(module_t(6001, 'Setup ', null, '01-JAN-98', 100),
module_t(6002, 'BenchMark', null, '05-FEB-98',20) ,
module_t(6003, 'Purchase', null, '15-MAR-98', 50),
module_t(6004, 'Install', null, '15-MAR-98',44),
module_t(6005, 'Launch', null,'12-MAY-98',34))) };
} catch ( Exception e) {
System.out.println("Error:insertProject2");
}
// Assign project owner to this project
try {
#sql { UPDATE Projects pr
SET owner=(SELECT ref(pa) FROM participants pa WHERE pa.empno = 7698)
WHERE pr.id=600 };
} catch ( Exception e) {
System.out.println("Error:insertProject2:update");
}
}
7.5.3 Selecting a Nested Table into a Host Expression

This example presents an operation that works directly at the detail level of the nested
table.
static ModuletblT mymodules=null;
...
public static void getModules2(int projId)

throws Exception
{
System.out.println("Display modules for project " + projId );
try {
#sql {SELECT modules INTO :mymodules
FROM projects WHERE id=:projId };
showArray(mymodules);
} catch(Exception e) {
System.out.println("Error:getModules2");
}
}
public static void showArray(ModuletblT a)

{
try {
if ( a == null )
System.out.println( "The array is null" );
else {
System.out.println( "printing ModuleTable array object of size "
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Chapter 7
+a.length());
ModuleT[] modules = a.getArray();
for (int i=0;i<modules.length; i++) {

ModuleT module = modules[i];
System.out.println("module "+module.getModuleId()+
", "+module.getModuleName()+
", "+module.getModuleStartDate()+
", "+module.getModuleDuration());
}
}
}
catch( Exception e ) {
System.out.println("Show Array");
}
}
7.5.4 Manipulating a Nested Table Using TABLE Syntax

This example uses TABLE syntax to work at the detail level to access and update
nested table elements directly, based on master-level criteria.
The assignModule() method selects a nested table of MODULE_T objects from the
MODULES column of the PROJECTS table, then updates MODULE_NAME for a particular row
of the nested table. Similarly, the deleteUnownedModules() method selects a nested
table of MODULE_T objects, then deletes any unowned modules in the nested table,
where MODULE_OWNER is null.
These methods use table alias syntax, as discussed previously. In this case, m is used
for the nested table, and p is used for the participants table.
/* assignModule
Illustrates accessing the nested table using the TABLE construct
and updating the nested table row
*/
public static void assignModule(int projId, String moduleName,
String modOwner) throws Exception
{
System.out.println("Update:Assign '"+moduleName+"' to '"+ modOwner+"'");
try {
#sql {UPDATE TABLE(SELECT modules FROM projects WHERE id=:projId) m
SET m.module_owner=
(SELECT ref(p) FROM participants p WHERE p.ename= :modOwner)
WHERE m.module_name = :moduleName };
System.out.println("Error:insertModules");
}
}
/* deleteUnownedModules
// Demonstrates deletion of the Nested table element
*/
public static void deleteUnownedModules(int projId)

throws Exception
{
System.out.println("Deleting Unowned Modules for Project " + projId);
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Chapter 7
try {
#sql { DELETE TABLE(SELECT modules FROM projects WHERE id=:projId) m
WHERE m.module_owner IS NULL };
System.out.println("Error:deleteUnownedModules");
}
}
7.5.5 Selecting Data from a Nested Table Using a Nested Iterator

SQLJ supports the use of nested iterators as a way of accessing nested tables. This
requires CURSOR syntax, as used in the following example. The code defines a named
iterator class, ModuleIter, then uses that class as the type for a modules column in
another named iterator class, ProjIter. Inside a populated ProjIter instance, each
modules item is a nested table rendered as a nested iterator.
The CURSOR syntax is part of the nested SELECT statement that populates the nested
iterators. Once the data has been selected, it is output to the user through the iterator
accessor methods.
This example uses required table alias syntax, as discussed previously. In this case, a
for the projects table and b for the nested table.
...
// The Nested Table is accessed using the ModuleIter

// The ModuleIter is defined as Named Iterator
#sql public static iterator ModuleIter(int moduleId ,

String moduleName ,
String moduleOwner);
// Get the Project Details using the ProjIter defined as

// Named Iterator. Notice the use of ModuleIter:
#sql public static iterator ProjIter(int id,

String name,
String owner,
Date start_date,
ModuleIter modules);
...
public static void listAllProjects() throws SQLException

{
System.out.println("Listing projects...");
// Instantiate and initialize the iterators
ProjIter projs = null;

ModuleIter mods = null;
#sql projs = {SELECT a.id,
a.name,
initcap(a.owner.ename) as "owner",
a.start_date,
CURSOR (
SELECT b.module_id AS "moduleId",
b.module_name AS "moduleName",
initcap(b.module_owner.ename) AS "moduleOwner"
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Chapter 7
FROM TABLE(a.modules) b) AS "modules"

FROM projects a };
// Display Project Details
while (projs.next()) {
System.out.println( "\n'" + projs.name() + "' Project Id:"
+ projs.id() + " is owned by " +"'"+ projs.owner() +"'"
+ " start on "
+ projs.start_date());
// Notice the modules from the ProjIter are assigned to the module
// iterator variable
mods = projs.modules();
System.out.println ("Modules in this Project are : ");
// Display Module details
while(mods.next()) {
System.out.println (" "+ mods.moduleId() + " '"+
mods.moduleName() + "' owner is '" +
mods.moduleOwner()+"'" );
} // end of modules
mods.close();
} // end of projects
projs.close();
}
7.5.6 Selecting a VARRAY into a Host Expression

This section provides an example of selecting a VARRAY into a host expression.
Presume the following SQL definitions:
CREATE TYPE PHONE_ARRAY IS VARRAY (10) OF varchar2(30)
/
(
street VARCHAR(60),
city VARCHAR(30),
state CHAR(2),
zip_code CHAR(5)
)
/
(
name VARCHAR(30),
ssn NUMBER,
addr ADDRESS
)
/

( empnumber INTEGER PRIMARY KEY,
person_data REF person,
manager REF person,
office_addr address,
salary NUMBER,
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Serialized Java Objects
phone_nums phone_array
)
/
And presume that you created a PhoneArray custom collection class to map from the
PHONE_ARRAY SQL type.
The following method selects a row from this table, placing the data into a host
variable of the PhoneArray type:
private static void selectVarray() throws SQLException
{
PhoneArray ph;
#sql {select phone_nums into :ph from employees where empnumber=2001};
System.out.println(
"there are "+ph.length()+" phone numbers in the PhoneArray. They are:");
String [] pharr = ph.getArray();

for (int i=0;i<pharr.length;++i)
System.out.println(pharr[i]);
}
7.5.7 Inserting a Row that Includes a VARRAY

This section provides an example of inserting data from a host expression into a
VARRAY, using the same SQL definitions and custom collection class (PhoneArray) as
in the previous section.
The following methods populate a PhoneArray instance and use it as a host variable,
inserting its data into a VARRAY in the database:
// creates a varray object of PhoneArray and inserts it into a new row
private static void insertVarray() throws SQLException
{
PhoneArray phForInsert = consUpPhoneArray();
// clean up from previous demo runs
#sql {delete from employees where empnumber=2001};
// insert the PhoneArray object
#sql {insert into employees (empnumber, phone_nums)
values(2001, :phForInsert)};
}
private static PhoneArray consUpPhoneArray()

{
String [] strarr = new String[3];
strarr[0] = "(510) 555.1111";
strarr[1] = "(617) 555.2222";
strarr[2] = "(650) 555.3333";
return new PhoneArray(strarr);
}
7.6 Serialized Java Objects

When writing and reading instances of Java objects to or from the database, it is
sometimes advantageous to define a SQL object type that corresponds to your Java
class and use the mechanisms of mapping custom Java classes described previously.
This fully permits SQL queries on your Java objects.
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Chapter 7
In some cases, however, you may want to store Java objects "as-is" and retrieve them
later, using database columns of the RAW or BLOB type. There are different ways to
accomplish this:
• You can map a serializable Java class to RAW or BLOB columns by using a
nonstandard extension to the type map facility or by adding a type code field to the
serializable class, so that instances of the serializable class can be stored as RAW
or BLOB.
• You can use the ORAData facility to define a serializable wrapper class whose
instances can be stored in RAW or BLOB columns.
Serializing in any of these ways works for any Oracle SQLJ run-time library.
• Serializing Java Classes to RAW and BLOB Columns
• SerializableDatum: an ORAData Implementation
• SerializableDatum in SQLJ Applications
• SerializableDatum (Complete Class)
7.6.1 Serializing Java Classes to RAW and BLOB Columns

If you want to store instances of Java classes directly in RAW or BLOB columns,
then you must meet certain nonstandard requirements to specify the desired SQL-
Java mapping. Note that in SQLJ statements the serializable Java objects can be
transparently read and written as if they were built-in types.
You have two options in specifying the SQL-Java type mapping:
• Declare a type map in the connection context declaration and use this type map to
specify mappings.
• Use the public static final field _SQL_TYPECODE to specify the mapping.
Defining a Type Map for Serializable Classes

Consider an example where SAddress, pack.SPerson, and pack.Manager.InnerSPM,
where InnerSPM is an inner class of Manager, are serializable Java classes. In other
words, these classes implement the java.io.Serializable interface.
You must use the classes only in statements that use explicit connection context
instances of a declared connection context type, such as SerContext in the following
example:
SAddress a =...;
pack.SPerson p =...;
pack.Manager.InnerSPM pm =...;
SerContext ctx = new SerContext(url,user,pwd,false);
#sql [ctx] { ... :a ... :OUT p ... :INOUT pm ... };
The following is required:

• The connection context type must have been declared using the typeMap
attribute of a with clause to specify an associated class implementing
java.util.PropertyResourceBundle. In the example, SerContext may be
declared as follows.
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Chapter 7
#sql public static context SerContext with (typeMap="SerMap");

• The type map resource must provide nonstandard mappings from RAW or BLOB
columns to the serializable Java classes. This mapping is specified with entries of
the following form, depending on whether the Java class is mapped to a RAW or a
BLOB column:
oracle-class.java_class_name=JAVA_OBJECT RAW
oracle-class.java_class_name=JAVA_OBJECT BLOB
The keyword oracle-class marks this as an Oracle-specific extension. In the

example, the SerMap.properties resource file may contain the following entries:
oracle-class.SAddress=JAVA_OBJECT RAW
oracle-class.pack.SPerson=JAVA_OBJECT BLOB
oracle-class.packManager$InnerSPM=JAVA_OBJECT RAW
Although the period (.) separates package and class names, you must use the
dollar sign ($) to separate an inner class name.
Note that this Oracle-specific extension can be placed in the same type map resource
as standard SQLData type map entries.
Using Fields to Determine Mapping for Serializable Classes

As an alternative to using a type map for a serializable class, you can use static fields
in the serializable class to determine type mapping. You can add either of the following
fields to a class that implements the java.io.Serializable interface, such as the
SAddress and SPerson classes from the preceding example:
public final static int _SQL_TYPECODE = oracle.jdbc.OracleTypes.RAW;
public final static int _SQL_TYPECODE = oracle.jdbc.OracleTypes.BLOB;
Note:
Using the type map facility supersedes manually adding the _SQL_TYPECODE
field to the class.
Limitations on Serializing Java Objects

You should be aware of the effect of serialization. If two objects, A and B, share the
same object, C, then upon serialization and subsequent deserialization of A and B,
each will point to its own clone of the object C. Sharing is broken.
In addition, note that for a given Java class, you can declare only one kind of
serialization: either into RAW or into BLOB. The SQLJ translator can check only that
the actual usage conforms to either RAW or BLOB.
RAW columns are limited in size. You might experience run-time errors if the actual size
of the serialized Java object exceeds the size of the column.
Column size is much less restrictive for BLOB columns. Writing a serialized Java object
to a BLOB column is supported by Oracle JDBC Oracle Call Interface (OCI) driver
and Oracle JDBC Thin driver. Retrieving a serialized object from a BLOB column is
supported by all Oracle JDBC drivers since Oracle9i.
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Finally, treating serialized Java objects this way is an Oracle-specific extension and
requires Oracle SQLJ run time as well as either the default Oracle-specific code
generation (-codegen=oracle during translation) or, for ISO standard code generation
(-codegen=iso), Oracle-specific profile customization.
10iProd: Note that future versions of Oracle might support SQL types that directly
encapsulate Java serialized objects. These are described as JAVA_OBJECT SQL
types in JDBC 2.0. At that point, you can replace each of the BLOB and RAW
designations by the names of their corresponding JAVA_OBJECT SQL types, and you
can drop the oracle- prefix on the entries.
Note:
The implementation of this particular serialization mechanism does not use
JDBC type maps. The map (to BLOB or to RAW) is hardcoded in the Oracle
profile customization at translation time, or is generated directly into Java
code.
7.6.2 SerializableDatum: an ORAData Implementation

"Additional Uses for ORAData Implementations" includes examples of situations where
you might want to define a custom Java class that maps to some oracle.sql.* type
other than oracle.sql.STRUCT, oracle.sql.REF, or oracle.sql.ARRAY.
An example of such a situation is if you want to serialize and deserialize Java objects
into and out of RAW fields, with a custom Java class that maps to the oracle.sql.RAW
type. This could apply equally to BLOB fields, with a custom Java class that maps to the
oracle.sql.BLOB type.
This section presents an example of such an application, creating a class,

SerializableDatum, that implements the ORAData interface and follows the general
form of custom Java classes. The example starts with a step-by-step approach to the
development of SerializableDatum, followed by the complete sample code.
Note:
This application uses classes from the java.io, java.sql, oracle.sql, and
oracle.jdbc packages. The import statements are not shown here.
1. Begin with a skeleton of the class.

public class SerializableDatum implements ORAData
{
// Client methods for constructing and accessing the Java object
public Datum toDatum(java.sql.Connection c) throws SQLException

{
// Implementation of toDatum()
}
public static ORADataFactory getORADataFactory()
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{
return FACTORY;
}
private static final ORADataFactory FACTORY =

// Implementation of an ORADataFactory for SerializableDatum
// Construction of SerializableDatum from oracle.sql.RAW
public static final int _SQL_TYPECODE = OracleTypes.RAW;

}
SerializableDatum does not implement the ORADataFactory interface, but its

getORADataFactory() method returns a static member that implements this
interface.
The _SQL_TYPECODE is set to OracleTypes.RAW because this is the data type being
read from and written to the database. The SQLJ translator needs this type code
information in performing online type-checking to verify compatibility between the
user-defined Java type and the SQL type.
2. Define client methods that perform the following:
• Create a SerializableDatum object.
• Populate a SerializableDatum object.
• Retrieve data from a SerializableDatum object.
// Client methods for constructing and accessing a SerializableDatum
private Object m_data;

public SerializableDatum()
{
m_data = null;
}
public void setData(Object data)
{
m_data = data;
}
public Object getData()
{
return m_data;
}
3. Implement a toDatum() method that serializes data from a SerializableDatum
object to an oracle.sql.RAW object. The implementation of toDatum() must return
a serialized representation of the object in the m_data field as an oracle.sql.RAW
instance.
try {
ByteArrayOutputStream os = new ByteArrayOutputStream();
ObjectOutputStream oos = new ObjectOutputStream(os);
oos.writeObject(m_data);
oos.close();
return new RAW(os.toByteArray());
} catch (Exception e) {
throw new SQLException("SerializableDatum.toDatum: "+e.toString()); }
4. Implement data conversion from an oracle.sql.RAW object to a
SerializableDatum object. This step deserializes the data.
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// Constructing SerializableDatum from oracle.sql.RAW
private SerializableDatum(RAW raw) throws SQLException

{
try {
InputStream rawStream = new ByteArrayInputStream(raw.getBytes());
ObjectInputStream is = new ObjectInputStream(rawStream);
m_data = is.readObject();
is.close();
throw new SQLException("SerializableDatum.create: "+e.toString()); }
}
5. Implement an ORADataFactory. In this case, it is implemented as an anonymous
class.
new ORADataFactory()
{
public ORAData create(Datum d, int sqlCode) throws SQLException
{
if (sqlCode != _SQL_TYPECODE)
{
throw new SQLException
("SerializableDatum: invalid SQL type "+sqlCode);
}
return (d==null) ? null : new SerializableDatum((RAW)d);
}
};
7.6.3 SerializableDatum in SQLJ Applications

Given the SerializableDatum class created in the preceding section, this section
shows how to use an instance of it in a SQLJ application, both as a host variable and
as an iterator column.
Presume the following table definition:
CREATE TABLE PERSONDATA (NAME VARCHAR2(20) NOT NULL, INFO RAW(2000));
SerializableDatum as Host Variable

The following uses a SerializableDatum instance as a host variable:
...
SerializableDatum pinfo = new SerializableDatum();
pinfo.setData (
new Object[] {"Some objects", new Integer(51), new Double(1234.27) } );
String pname = "MILLER";
#sql { INSERT INTO persondata VALUES(:pname, :pinfo) };
...
SerializableDatum in Iterator Column

Following is an example of using SerializableDatum as a named iterator column:
#sql iterator PersonIter (SerializableDatum info, String name);
...
PersonIter pcur;
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#sql pcur = { SELECT * FROM persondata WHERE info IS NOT NULL };

while (pcur.next())
{
System.out.println("Name:" + pcur.name() + " Info:" + pcur.info());
}
pcur.close();
...
7.6.4 SerializableDatum (Complete Class)

The following is complete code for the SerializableDatum class, which was
developed in step-by-step fashion in the preceding sections.
import java.io.*;
import java.sql.*;
import oracle.sql.*;
import oracle.jdbc.*;
public class SerializableDatum implements ORAData

{
// Client methods for constructing and accessing a SerializableDatum
private Object m_data;

public SerializableDatum()
{
m_data = null;
}
public void setData(Object data)
{
m_data = data;
}
public Object getData()
{
return m_data;
}
public Datum toDatum(Connection c) throws SQLException

{
try {
ByteArrayOutputStream os = new ByteArrayOutputStream();
ObjectOutputStream oos = new ObjectOutputStream(os);
oos.writeObject(m_data);
oos.close();
return new RAW(os.toByteArray());
throw new SQLException("SerializableDatum.toDatum: "+e.toString()); }
}
public static ORADataFactory getORADataFactory()

{
return FACTORY;
}
private static final ORADataFactory FACTORY =
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Weakly Typed Objects, References, and Collections
new ORADataFactory()
{
public ORAData create(Datum d, int sqlCode) throws SQLException
{
if (sqlCode != _SQL_TYPECODE)
{
throw new SQLException(
"SerializableDatum: invalid SQL type "+sqlCode);
}
return (d==null) ? null : new SerializableDatum((RAW)d);
}
};
// Constructing SerializableDatum from oracle.sql.RAW
private SerializableDatum(RAW raw) throws SQLException

{
try {
InputStream rawStream = new ByteArrayInputStream(raw.getBytes());
ObjectInputStream is = new ObjectInputStream(rawStream);
m_data = is.readObject();
is.close();
throw new SQLException("SerializableDatum.create: "+e.toString()); }
}
public static final int _SQL_TYPECODE = OracleTypes.RAW;

}
7.7 Weakly Typed Objects, References, and Collections

Weakly typed objects, references, and collections are supported by SQLJ. Their use
is not generally recommended, and there are some specific restrictions, but in some
circumstances they can be useful. For example, you might have generic code that can
use "any STRUCT" or "any REF".

• Support for Weakly Typed Objects_ References_ and Collections
• Restrictions on Weakly Typed Objects_ References_ and Collections
7.7.1 Support for Weakly Typed Objects, References, and Collections

In using Oracle objects, references, or collections in a SQLJ application, you have the
option of using generic and weakly typed java.sql or oracle.sql instances instead
of the strongly typed custom object, reference, and collection classes that implement
the ORAData interface or the strongly typed custom object classes that implement
the SQLData interface. Note that if you use SQLData implementations for your custom
object classes, then you will have no choice but to use weakly typed custom reference
instances.
The following weak types can be used for iterator columns or host expressions in the
Oracle SQLJ implementation:
• java.sql.Struct or oracle.sql.STRUCT for objects
• java.sql.Ref or oracle.sql.REF for object references
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• java.sql.Array or oracle.sql.ARRAY for collections

In host expressions, they are supported as follows:
• As input host expressions
• As output host expressions in an INTO-list
Using these weak types is not generally recommended, however, as you would lose all
the advantages of the strongly typed paradigm that SQLJ offers.
Each attribute in a STRUCT object or each element in an ARRAY object is stored in an
oracle.sql.Datum object, with the underlying data being in the form of the appropriate
oracle.sql.* subtype of Datum, such as oracle.sql.NUMBER or oracle.sql.CHAR.
Attributes in a STRUCT object are nameless. Because of the generic nature of the
STRUCT and ARRAY classes, SQLJ cannot perform type checking where objects or
collections are written to or read from instances of these classes.
It is generally recommended that you use custom Java classes for objects, references,
and collections.
7.7.2 Restrictions on Weakly Typed Objects, References, and

Collections
A weakly typed object (Struct or STRUCT instance), reference (Ref or REF instance),
or collection (Array or ARRAY instance) cannot be used in host expressions in the
following circumstances:
• IN parameter if null
• OUT or INOUT parameter in a stored procedure or function call
• OUT parameter in a stored function result expression
They cannot be used in these ways, because there is no way to know the underlying
SQL type name, such as Person, which is required by Oracle JDBC driver to
materialize an instance of a user-defined type in Java.
7.8 Oracle OPAQUE Types

Oracle OPAQUE types are abstract data types. With data implemented as simply a
series of bytes, the internal representation is not exposed. Typically an OPAQUE type
will be provided by Oracle, not implemented by a customer.
OPAQUE types are similar in some basic ways to object types, with similar concepts
of static methods, instances, and instance methods. Typically, only the methods
supplied with an OPAQUE type allow you to manipulate the state and internal byte
representation. In Java, an OPAQUE type can be represented as oracle.sql.OPAQUE
or as a custom class implementing the oracle.sql.ORAData interface. On the client-
side, Java code can be implemented to manipulate the bytes, assuming the byte
pattern is known.
A key example of an OPAQUE type is XMLType, provided with Oracle Database 12c
Release 2 (12.2). This Oracle-provided type facilitates handling XML data natively in
the database.
SYS.XMLType offers the following features, exposed through the Java
oracle.xdb.XMLType class:
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• It can be used as the data type of a column in a table or view. XMLType can store
any content but is designed to optimally store XML content. An instance of it can
represent an XML document in SQL.
• It has a SQL API with built-in member functions that operate on XML content. For
example, you can use XMLType functions to create, query, extract, and index XML
data stored in an Oracle Database 12c Release 1 (12.1) instance.
• It can be used in stored procedures for parameters, return values, and variables.
• Its functionality is also available through APIs provided in PL/SQL, Java, and C
(OCI).
See Also:
Oracle XML DB Developer's Guide
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8
Advanced Language Features
This chapter discusses advanced SQLJ language features for use in coding your
application. For more basic topics, refer to Basic Language Features.
The following topics are discussed:
• Connection Contexts
• Execution Contexts
• Multithreading in SQLJ
• Iterator Class Implementation and Advanced Functionality
• Advanced Transaction Control
• SQLJ and JDBC Interoperability
• Support for Dynamic SQL
• Using Stored Outlines
• Using Plan Baselines
8.1 Connection Contexts

SQLJ supports the concept of connection contexts, allowing strongly typed
connections for use with different sets of SQL entities. You can think of a connection
context as being associated with a particular set of SQL entities, such as tables, views,
and stored procedures. SQLJ lets you declare additional connection context classes
so that you can use each class for connections that use a particular set of SQL
entities. Different instances of a single connection context class are not required to use
the same physical entities or connect to the same schema, but will at least use sets of
entities with the same names and data types.
See Also:
"Connection Considerations" for an overview of connection basics, focusing
on situations where you are using just a single set of SQL entities and a
single connection context class.

• Connection Context Concepts
• Connection Context Logistics
• Declaring and Using a Connection Context Class
• Example of Multiple Connection Contexts
• Implementation and Functionality of Connection Context Classes
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• Using the IMPLEMENTS Clause in Connection Context Declarations

• Semantics-Checking of Your Connection Context Usage
• Standard Data Source Support
• SQLJ-Specific Data Sources
• SQLJ-Specific Connection JavaBeans for JavaServer Pages
• SQLJ Support for Global Transactions
• Connecting to PDBs
8.1.1 Connection Context Concepts

If your application uses different sets of SQL entities, then you will typically want to
declare and use one or more additional connection context classes, as discussed in
"Overview of SQLJ Declarations". Each connection context class can be used for a
particular set of interrelated SQL entities, meaning that all the connections you define
using a particular connection context class will use tables, views, stored procedures,
and so on, which have the same names and use the same data types.
An example of a set of SQL entities is the set of tables and stored procedures used
by the Human Resources (HR) department. Perhaps they use the EMPLOYEES and
DEPARTMENTS tables and the CHANGE_DEPT and UPDATE_HEALTH_PLAN stored procedures.
Another set of SQL entities might be the set of tables and procedures used by the
Payroll department, perhaps consisting of the EMPS table (another table of employees,
but different than the one used by HR) and the GIVE_RAISE and CHANGE_WITHHOLDING
stored procedures.
The advantage in tailoring connection context classes to sets of SQL entities is in the
degree of online semantics-checking that this allows. Online checking verifies that all
the SQL entities appearing in SQLJ statements that use a given connection context
class match SQL entities found in the exemplar schema used during translation. An
exemplar schema is a database account that SQLJ connects to for online checking
of all the SQLJ statements that use a particular connection context class. You
provide exemplar schemas to the translator through the SQLJ command-line -user,
-password, and -url options. An exemplar schema may or may not be the same
account your application will use at run time.
See Also:
If you have SQLJ statements that use a broad and perhaps unrelated group of SQL
entities, but you use only a single connection context class for these statements, then
the exemplar schema you provide must be very general. It must contain all the tables,
views, and stored procedures used throughout all the statements. Alternatively, if all
the SQLJ statements using a given connection context class use a tight, presumably
interrelated, set of SQL entities, then you can provide a more specific exemplar
schema that enables more thorough and meaningful semantics-checking.
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Note:
• Be aware that a connection context class declaration does not define

a set of SQL entities to be used with the declared connection context
class, and it is permissible to use the same connection context class for
connections that use disparate and unrelated sets of entities. How you
use your connection context classes is at your discretion. All that limits
the SQL entities you can use with a particular connection context class
are the set of entities available in the exemplar schema, if you use online
semantics-checking during translation, and the set of entities available in
the schema you connect to at run time, using instances of the connection
context class.
• If you use qualified SQL names in your application, such as
HR.EMPLOYEES, which specifies the schema where the entity resides, then
the exemplar schema, if you use online checking, and run-time schema
must have permission to access resources by these fully qualified
names.
• It is possible to use a single connection context class, even for
connections to databases from different vendors, as long as each
schema you connect to has entities that are accessible by the same
names and that use compatible data types.
8.1.2 Connection Context Logistics

Declaring a connection context class results in the SQLJ translator defining a class
for you in the translator-generated code. In addition to any connection context classes
that you declare, there is always the default connection context class:
sqlj.runtime.ref.DefaultContext
When you construct a connection context instance, specify a particular schema and a
particular session and transaction in which SQL operations will execute. You typically
accomplish this by specifying a user name, password, and database URL as input
to the constructor of the connection context class. The connection context instance
manages the set of SQL operations performed during the session.
In each SQLJ statement, you can specify a connection context instance to use. The
following example shows basic declaration and use of a connection context class,
MyContext, to connect to two different schemas. For typical usage, assume these
schemas include a set of SQL entities with common names and data types.
#sql context MyContext;
...
MyContext mctx1 = new MyContext
MyContext mctx2 = new MyContext
("jdbc:oracle:thin@localhost:5221/myservice", "brian", "mypasswd", false);
Note that connection context class constructors specify a boolean auto-commit

parameter. In addition, note that you can connect to the same schema with different
connection context instances. In the preceding example, both mctx1 and mctx2 can
specify HR/hr if desired. However, during run time, one connection context instance
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would not see changes to the database made from the other until the changes
are committed. The only exception to this would be if both connection context
instances were created from the same underlying Java Database Connectivity (JDBC)
connection instance. One of the constructors of any connection context class takes a
JDBC connection instance as input.
8.1.3 Declaring and Using a Connection Context Class

This section gives a detailed example of how to declare a connection context class,
then define a database connection using an instance of the class.
A connection context class has constructors for opening a connection to a
database schema that take any of the following input parameter sets (as with the
DefaultContext class):
• URL (String), user name (String), password (String), auto-commit (boolean)

• URL (String), java.util.Properties object, auto-commit (boolean)
• URL (String fully specifying connection and including user name and password),
auto-commit setting (boolean)
Note:
• When using the constructor that takes a JDBC connection object, do not
initialize the connection context instance with a null JDBC connection.
• The auto-commit setting determines whether SQL operations are
automatically committed. For more information, refer to "Basic
Transaction Control".
• If a connection context class is declared with a data source with clause,
then it incorporates a different set of constructors. Refer to "Standard
Data Source Support" for more information.
Declaring the Connection Context Class

The following declaration creates a connection context class:
#sql context OrderEntryCtx <implements_clause> <with_clause>;
This results in the SQLJ translator generating a class that implements the
sqlj.runtime.ConnectionContext interface and extends some base class, probably
an abstract class, that also implements the ConnectionContext interface. This base
class would be a feature of the particular SQLJ implementation you are using. The
implements clause and with clause are optional, specifying additional interfaces to
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See Also:
The following is an example of what the SQLJ translator generates (with method
implementations omitted):
class OrderEntryCtx implements sqlj.runtime.ConnectionContext

extends ...
{
public OrderEntryCtx(String url, Properties info, boolean autocommit)
throws SQLException {...}
public OrderEntryCtx(String url, boolean autocommit)
throws SQLException {...}
public OrderEntryCtx(String url, String user, String password,
boolean autocommit) throws SQLException {...}
public OrderEntryCtx(Connection conn) throws SQLException {...}
public OrderEntryCtx(ConnectionContext other) throws SQLException {...}
public static OrderEntryCtx getDefaultContext() {...}

public static void setDefaultContext(OrderEntryCtx ctx) {...}
}
Creating a Connection Context Instance

Continuing the preceding example, instantiate the OrderEntryCtx class with the
following syntax:
OrderEntryCtx myOrderConn = new OrderEntryCtx
(url, username, password, autocommit);
For example:
OrderEntryCtx myOrderConn = new OrderEntryCtx
This is accomplished in the same way as instantiating the DefaultContext class.

All connection context classes, including DefaultContext, have the same constructor
signatures.
Note:
• You typically must register your JDBC driver prior to constructing a

connection context instance. Refer to "Driver Selection and Registration
for Run Time".
• If a connection context class is declared with a data source with clause,
then it incorporates a different set of constructors. Refer to "Standard
Data Source Support" for more information.
Specifying a Connection Context Instance for a SQLJ Clause

Recall that the basic SQLJ statement syntax is as follows:
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#sql <[<conn><, ><exec>]> { SQL operation };
Specify the connection context instance inside square brackets following the #sql
token. For example, in the following SQLJ statement, the connection context instance
is myOrderConn from the previous example:
#sql [myOrderConn] { UPDATE TAB2 SET COL1 = :w WHERE :v < COL2 };
In this way, you can specify an instance of either the DefaultContext class or any
declared connection context class.
Closing a Connection Context Instance

It is advisable to close all connection context instances when you are done.
Each connection context class includes a close() method, as discussed for the
DefaultContext class in "Closing Connections".
In closing a connection context instance that shares the underlying connection with
another connection instance, you might want to keep the underlying connection open.
8.1.4 Example of Multiple Connection Contexts

The following is an example of a SQLJ application using multiple connection contexts.
It implicitly uses an instance of the DefaultContext class for one set of SQL entities
and an instance of the declared DeptContext connection context class for another set
of SQL entities.
This example uses the static Oracle.connect() method to establish a default
connection, then constructs an additional connection by using the static
Oracle.getConnection() method to pass another DefaultContext instance to the
DeptContext constructor. As previously mentioned, this is just one of several ways you
can construct a SQLJ connection context instance.
import java.sql.SQLException;
// declare a new context class for obtaining departments

#sql context DeptContext;
#sql iterator Employees (String ename, int deptno);
class MultiSchemaDemo
{
public static void main(String[] args) throws SQLException
{
// set the default connection to the URL, user, and password
Oracle.connect(MultiSchemaDemo.class, "connect.properties");
// create a context for querying department info using

// a second connection
DeptContext deptCtx =
new DeptContext(Oracle.getConnection(MultiSchemaDemo.class,
"connect.properties"));
new MultiSchemaDemo().printEmployees(deptCtx);
deptCtx.close();
}
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// performs a join on deptno field of two tables accessed from

// different connections.
void printEmployees(DeptContext deptCtx) throws SQLException
{
// obtain the employees from the default context
Employees emps;
#sql emps = { SELECT first_name, department_id FROM employees };
// for each employee, obtain the department name

// using the dept table connection context
while (emps.next()) {
String dname;
int deptno = emps.deptno();
#sql [deptCtx] {
SELECT dname INTO :dname FROM departments WHERE department_id = :deptno
};
System.out.println("employee: " +emps.ename() +
", department: " + dname);
}
emps.close();
}
}
8.1.5 Implementation and Functionality of Connection Context Classes

This section discusses how SQLJ implements connection context classes, including
the DefaultContext class, and what noteworthy methods they contain. As mentioned
earlier, the DefaultContext class and all generated connection context classes
implement the ConnectionContext interface.
Note:
Extending connection context classes is not permitted in the SQLJ
specification and is not supported by the Oracle SQLJ implementation.
ConnectionContext Interface
Each connection context class implements the sqlj.runtime.ConnectionContext
interface.
Basic methods specified by this interface include the following:
• close(boolean CLOSE_CONNECTION/KEEP_CONNECTION): Releases all resources
used in maintaining this connection and closes any open connected profiles.
It may close the underlying JDBC connection, depending on whether
CLOSE_CONNECTION or KEEP_CONNECTION is specified. These are static boolean
constants of the ConnectionContext interface.
• getConnection(): Returns the underlying JDBC connection object for this
connection context instance.
• getExecutionContext(): Returns the default ExecutionContext instance for this
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See Also:
"Execution Contexts"
Additional Connection Context Class Methods

In addition to the methods specified and defined in the ConnectionContext interface,
each connection context class defines the following methods:
• YourCtxClass getDefaultContext(): This is a static method that returns the
default connection context instance for a given connection context class.
• setDefaultContext(YourCtxClass connctxinstance): This is a static method
that defines the given connection context instance as the default connection
context instance for its class.
Although it is true that you can use an instance of only the DefaultContext class
as your default connection, it might still be useful to designate an instance of a
declared connection context class as the default context for that class, using the
setDefaultContext() method. Then you could conveniently retrieve it using the
getDefaultContext() method of the particular class. This would enable you, for
example, to specify a connection context instance for a SQLJ executable statement
as follows:
...
MyContext myctx1 = new MyContext(url, user, password, autocommit);
...
MyContext.setDefaultContext(myctx1);
...
#sql [MyContext.getDefaultContext()] { SQL operations };
...
Additionally, each connection context class defines methods for control of SQLJ
statement caching. The following are the static methods:
• setDefaultStmtCacheSize(int)
• int getDefaultStmtCacheSize()
The following are the instance methods:
• setStmtCacheSize(int)
By default, statement caching is enabled.
8.1.6 Using the IMPLEMENTS Clause in Connection Context

Declarations
There may be situations where it is useful to implement an interface in your connection
context declarations. For example, you may want to define an interface that exposes
just a subset of the functionality of a connection context class. More specifically, you
may want a class that has the getConnection() functionality, but does not have other
functionality of a connection context class.
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You can create an interface called HasConnection, for example, that specifies a
getConnection() method, but does not specify other methods found in a connection
context class. You can then declare a connection context class but expose only the
getConnection() functionality by assigning a connection context instance to a variable
of the HasConnection type, instead of to a variable that has the type of your declared
connection context class.
Assuming HasConnection is in the mypackage package, the declaration will be as
follows:
#sql public context MyContext implements mypackage.HasConnection;
You can then instantiate a connection instance as follows:

HasConnection myConn = new MyContext (url, username, password, autocommit);
For example:
HasConnection myConn = new MyContext
8.1.7 Semantics-Checking of Your Connection Context Usage

A significant feature of SQLJ is strong typing of connections, with each connection
context class typically used for operations on a particular set of interrelated SQL
entities. This does not mean that all the connection instances of a single class use
the same physical entities. Instead, they use entities that have the same properties,
such as names and privileges associated with tables and views, data types of their
rows, and names and definitions of stored procedures. This strong typing allows SQLJ
semantics-checking to verify during translation that you are using your SQL operations
correctly, with respect to your database connections.
To use online semantics-checking during translation, provide a sample schema, which
includes an appropriate set of SQL entities, for each connection context class. These
sample schemas are referred to as exemplar schemas. Provide exemplar schemas
through an appropriate combination of the SQLJ -user, -password, and -url options.
Following are two examples, one for the DefaultContext class and one for a declared
connection context class, where the user, password, and URL are all specified through
the -user option:
-user=HR/hr@jdbc:oracle:oci:@
-user@MyContext=HR/hr@jdbc:oracle:oci:@
During semantics-checking, the translator connects to the specified exemplar schema

for a particular connection context class and accomplishes the following:
• It examines each SQLJ statement in your code that specifies an instance of the
connection context class and checks its SQL operations, such as what tables you
access and what stored procedures you use.
• It verifies that entities in the SQL operations match the set of entities existing in the
exemplar schema.
It is your responsibility to pick an exemplar schema that represents the run-time
schema in appropriate ways. For example, it must have tables, views, stored
functions, and stored procedures with names and data types that match what are
used in your SQL operations, and with privileges set appropriately.
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If no appropriate exemplar schema is available during translation for one of your

connection context classes, then it is not necessary to specify SQLJ translator options
for that particular connection context class. In that case, SQLJ statements specifying
connection objects of that connection context class are semantically checked only to
the extent possible.
Note:
Remember that the exemplar schema you specify in your translator option
settings does not specify the schema to be used at run time. The exemplar
schema furnishes the translator only with a set of SQL entities to compare
against the entities you use in your SQLJ executable statements.
8.1.8 Standard Data Source Support

The JDBC 2.0 extended application programming interface (API) specifies the use
of data sources and Java Naming and Directory Interface (JNDI) as a portable
alternative to the DriverManager mechanism for obtaining JDBC connections. It
permits database connections to be established through a JNDI name lookup. This
name is bound to a particular database and schema prior to program run time through
a javax.sql.DataSource object, typically installed through a graphical user interface
(GUI) JavaBeans deployment tool. The name can be bound to different physical
connections without any source code changes simply by rebinding the name in the
directory service.
SQLJ uses the same mechanism to create connection context instances in a flexible
and portable way. Data sources can also be implemented using a connection pool or
distributed transaction service, as defined by the JDBC 2.0 extended API.
See Also:
Associating a Connection Context with a Data Source

In SQLJ it is natural to associate a connection context class with a logical schema, in
much the same way that a data source name serves as a symbolic name for a JDBC
connection. Combine both concepts by adding the data source name to the connection
context declaration. For example:
#sql context EmpCtx with (dataSource="jdbc/EmpDB");
Any connection context class that you declare with a dataSource property provides
additional constructors. To continue the EmpCtx example, the following constructors are
provided:
• EmpCtx(): Looks up the data source for jdbc/EmpDB and then calls the
getConnection() method on the data source to obtain a connection.
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• EmpCtx(String user, String password): Looks up the data source for jdbc/
EmpDB and calls the getConnection(user,password) method on the data source to
obtain a connection.
• EmpCtx(ConnectionContext ctx): Delegates to ctx to obtain a connection.
Any connection context class declared with a dataSource property also omits a
number of DriverManager-based constructors. Continuing the EmpCtx example, the
following constructors are omitted:
• EmpCtx(Connection conn)
• EmpCtx(String url, String user, String password, boolean autoCommit)
• EmpCtx(String url, boolean autoCommit)
• EmpCtx(String url, java.util.Properties info, boolean autoCommit)
• EmpCtx(String url, boolean autoCommit)
Auto-Commit Mode for Data Source Connections

The constructors based on data source, unlike those base on DriverManager, do not
include an explicit auto-commit parameter. They always use the auto-commit mode
defined by the data source.
Data sources are configured to have a default auto-commit mode depending on
the deployment scenario. For example, data sources in the server and middle tier
typically have auto-commit off. Those on the client may have it on. However, it is
also possible to configure data sources with a specific auto-commit setting. This
permits data sources to be configured for a particular application and deployment
scenario. Contrast this with JDBC URLs that may specify only a single database/driver
configuration.
Programs can verify and possibly override the current auto-commit setting with the
JDBC connection that underlies their connection context instance.
Note:
Be aware of the following points related to the auto-commit status of the
connections you establish:
• If you use the Oracle class, then auto-commit is off unless you turn it on
explicitly.
• If you use DefaultContext or a connection context class with
DriverManager-style constructors, then the auto-commit setting must
always be specified explicitly.
• If you use the data source mechanism, then the auto-commit setting
is inherited from the underlying data source. In most environments, the
data source object originates from JDBC and the auto-commit option
is on. To avoid unexpected behavior, always check the auto-commit
setting.
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Associating a Data Source with the Default Context

If a SQLJ program accesses the default connection context, and the default context
has not yet been set, then the SQLJ run time will use the SQLJ default data source
to establish its connection. The SQLJ default data source is bound to the JNDI name,
jdbc/defaultDataSource.
This mechanism provides a portable means to define and install a default JDBC
connection for the default SQLJ connection context.
Data Source Support Requirements

For your program to use data sources, you must supply the javax.sql.* and
javax.naming.* packages and an InitialContext provider in your Java environment.
The latter is required to obtain the JNDI context in which the SQLJ run time can look
up the data source object.
All SQLJ run-time libraries provided by Oracle support data sources. However, if you
use the runtime12ee library you must have javax.sql.* and javax.naming.* in your
classpath in order for the run time to load. By contrast, the other run-time libraries use
reflection to retrieve DataSource objects.
8.1.9 SQLJ-Specific Data Sources

The Oracle SQLJ implementation provides SQLJ-specific data source support in the
runtime12ee library. Currently, SQLJ-specific data sources can be used in client-side
or middle-tier applications, but not inside the server.
SQLJ-specific data sources extend JDBC data source functionality with methods that
return SQLJ connection context instances. This enables a SQLJ developer to manage
connection contexts just as a JDBC developer manages connections. In general, each
SQLJ-specific data source interface or class is based on a corresponding standard
JDBC data source interface or Oracle data source class.
SQLJ Data Source Interfaces

The sqlj.runtime.ConnectionContextFactory interface acts as a base interface for
SQLJ data source functionality. It is implemented by a set of more specialized Oracle
data source interfaces that add support for features such as connection pooling,
connection caching, or distributed transactions.
The ConnectionContextFactory interface specifies the following methods to return
SQLJ connection context instances:
• DefaultContext getDefaultContext()
• DefaultContext getDefaultContext(boolean autoCommit)
• DefaultContext getDefaultContext(String user, String password)
• DefaultContext getDefaultContext(String user, String password, boolean
autoCommit)
• ConnectionContext getContext(Class aContextClass)
• ConnectionContext getContext(Class aContextClass, boolean autoCommit)
• ConnectionContext getContext(Class aContextClass, String user, String
password)
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• ConnectionContext getContext(Class aContextClass, String user, String

password, boolean autoCommit)
The getDefaultContext methods return a sqlj.runtime.ref.DefaultContext
instance for the SQLJ default context. The getContext() methods return a
sqlj.runtime.ConnectionContext instance. Specifically, it returns an instance of a
user-declared connection context class that is specified in the method call.
For both getDefaultContext() and getContext(), there are signatures that enable
you to specify connection parameters for the JDBC connection that underlies the
connection context instance: the auto-commit setting, user and password settings, or
all three. If you do not specify the user and password, then they are obtained from
the underlying data source that generates the connection. If you do not specify an
auto-commit setting, then the default is false unless it was explicitly set to true for the
underlying data source.
Each Oracle data source interface that implements ConnectionContextFactory also
implements a standard JDBC data source interface to specify methods for the
appropriate functionality, such as for basic data sources, connection pooling data
sources, or distributed transaction (XA) data sources. Oracle has implemented the
SqljDataSource, SqljConnectionPoolDataSource, and SqljXADataSource interfaces,
located in the sqlj.runtime package and specified as follows:
• interface SqljDataSource extends javax.sql.DataSource,

ConnectionContextFactory { }
• interface SqljDataSource extends javax.sql.ConnectionPoolDataSource,
• interface SqljXADataSource extends javax.sql.XADataSource,
SQLJ Data Source Classes

Oracle provides SQLJ-specific counterparts for the following JDBC
data source classes: OracleDataSource, OracleConnectionPoolDataSource,
OracleXADataSource, OracleConnectionCacheImpl, OracleXAConnectionCacheImpl,
and OracleOCIConnectionPool.
See Also:
Oracle SQLJ-specific data source classes are located in two packages:

oracle.sqlj.runtime and oracle.sqlj.runtime.client.
The oracle.sqlj.runtime package includes the following:
• class OracleSqljDataSource extends oracle.jdbc.pool.OracleDataSource

implements ConnectionContextFactory
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Note:
The OracleSqljDataSource class implements the java.io.Serializable
interface. It is therefore serializable and can be used in clustered
environments, such as Oracle9i Application Server Containers for J2EE
(OC4J).
• class OracleSqljConnectionPoolDataSource extends

oracle.jdbc.pool.OracleConnectionPoolDataSource implements
ConnectionContextFactory
• abstract class OracleSqljXADataSource extends
oracle.jdbc.xa.OracleXADataSource implements ConnectionContextFactory
• class OracleSqljConnectionCacheImpl extends
oracle.jdbc.pool.OracleConnectonCacheImpl implements
• class OracleSqljXAConnectionCacheImpl extends
oracle.jdbc.pool.OracleXAConnectonCacheImpl implements
• class OracleSqljOCIConnectionPool extends
oracle.jdbc.pool.OracleOCIConnectionPool implements
Note:
• If you are using OracleSqljConnectionCacheImpl, then you need to

replace it with OracleSqljDataSource.
• If you are using OracleSqljXAConnectionCacheImpl, then you need to
replace it with OracleSqljXADataSource.
The oracle.sqlj.runtime.client package includes the following:
• class OracleSqljXADataSource extends

oracle.jdbc.xa.client.OracleXADataSource implements
You can use these classes in place of the corresponding JDBC classes that they
extend. They include the getDefaultContext() and getContext() methods. When
you call these methods, the following steps take place for you:
1. A new logical JDBC connection is acquired from the present data source.
2. A connection context instance is created from the logical connection and returned.
Examples: Using SQLJ Data Sources

When used in middle-tier environments, SQLJ-specific data sources, like JDBC data
sources, are bound to JNDI locations. You can do the binding explicitly, as in the
following example:
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//Initialize the data source

SqljXADataSource sqljDS = new OracleSqljXADataSource();
sqljDS.setUser("HR");
sqljDS.setPassword("hr");
sqljDS.setServerName("myserver");
sqljDS.setDatabaseName("orcl");
sqljDS.setDataSourceName("jdbc/OracleSqljXADS");
//Bind the data source to JNDI

Context ctx = new InitialContext();
ctx.bind("jdbc/OracleSqljXADS");
In a middle-tier OC4J environment, another alternative is to instantiate data

sources and bind them to JNDI through settings in the j2ee/home/config/data-
sources.xml file. For example, the following <data-source> element in that file
creates an OracleSqljXADataSource instance and binds it to the JNDI location, jdbc/
OracleSqljXADS:
<data-source
class="oracle.sqlj.runtime.OracleSqljXADataSource"
name="jdbc/OracleSqljXADS"
location="jdbc/OracleSqljXADS"
xa-location="jdbc/OracleSqljXADS/xa"
username="HR"
password="hr"
url="jdbc:oracle:thin:@myhost:5221/myservice"
/>
A SQLJ-specific data source bound to a JNDI location can be looked up and

used in creating connection context instances. The following code segment uses
information from the preceding <data-source> element to create connection context
instances, a DefaultContext instance and an instance of a user-declared MyCtx class,
respectively:
sqlj.runtime.SqljDataSource sqljDS;
InitialContext initCtx = new InitialContext();
sqljDS = (sqlj.runtime.SqljDataSource)initCtx.lookup("jdbc/OracleSqljXADS");
// getDefaultContext
DefaultContext ctx = sqljDS.getDefaultContext();
// getContext
/* Declare MyCtx connection context class. You could optionally use a "with"
clause to specify any desired connection parameters not available
through the underlying data source.
*/
#sql public static context MyCtx;
MyCtx ctx = (MyCtx) sqljDS.getContext(MyCtx.class);
8.1.10 SQLJ-Specific Connection JavaBeans for JavaServer Pages

Oracle has implemented a set of JavaBeans for database connections from within
Java Server Pages (JSP) pages.
The Oracle SQLJ implementation provides the following extensions of these
JavaBeans in the runtime12ee library for use in SQLJ JSP pages:
• oracle.sqlj.runtime.SqljConnBean
• oracle.sqlj.runtime.SqljConnCacheBean
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ConnBean and ConnCacheBean include methods that return JDBC connection objects.
SqljConnBean and SqljConnCacheBean extend this functionality to support a bean
property called ContextClass of type String and to return SQLJ connection context
instances.
Note:
The SqljConnBean class implements the java.io.Serializable interface. It
is therefore serializable and can be used in clustered environments, such as
OC4J.
SqljConnBean and SqljConnCacheBean provide the following methods:
• void setContextClass(String contextClassName)

• String getContextClass()
• DefaultContext getDefaultContext()
• ConnectionContext getContext()
The ContextClass property specifies the name of a user-declared connection context
class, if you are not using DefaultContext. You can set this property through the
setContextClass() method.
To retrieve a connection context instance, use getDefaultContext() or getContext(),

as appropriate. The former returns a sqlj.runtime.ref.DefaultContext instance,
and the latter returns a sqlj.runtime.ConnectionContext instance, specifically,
an instance of the class specified in the ContextClass property (by default,
DefaultContext).
However, note that the getDefaultContext() and getContext() methods are

implemented differently between SqljConnBean and SqljConnCacheBean.
Behavior of SqljConnBean (Simple Connections)

A SqljConnBean instance can wrap only one logical JDBC connection and one SQLJ
connection context instance at any given time.
The first getDefaultContext() or getContext() method call will create and return
a connection context instance based on the underlying JDBC connection. This
connection context instance will also be stored in the SqljConnBean instance.
Once a connection context instance has been created and stored, the behavior of
subsequent getDefaultContext() or getContext() calls will depend on the type of
the stored connection context and, for getContext(), on the connection context type
specified in the ContextClass property, as follows:
• For subsequent getDefaultContext() calls:

– If the stored connection context instance is a DefaultContext instance: The
method will keep returning that instance.
– If the stored connection context instance is not a DefaultContext instance:
The method will close the stored connection context instance and reuse the
underlying JDBC connection to create and return a new connection context
as a DefaultContext instance (regardless of the previous connection context
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type). This becomes the new connection context instance stored in the
SqljConnBean instance.
• For subsequent getContext() calls:
– If the stored connection context instance is of the same type as that specified
by the ContextClass property: The method will keep returning that instance.
– If the stored connection context instance is not of the same type as that
specified by ContextClass: The method will close the stored connection
context instance and reuse the underlying JDBC connection to create and
return a new connection context instance, an instance of what is specified in
ContextClass. This becomes the new connection context instance stored in
the SqljConnBean instance.
Note:
When SqljConnBean closes a connection context instance, it does so with
the KEEP_CONNECTION setting, leaving the underlying JDBC connection intact.
Behavior of SqljConnCacheBean (Connection Caching)

Unlike with SqljConnBean, the SqljConnCacheBean JavaBean creates and returns a
new connection context instance, based on a new logical JDBC connection, for each
invocation of getDefaultContext() or getContext(). The connection context type
will be DefaultContext for a getDefaultContext() call or the type specified in the
ContextClass property for a getContext() call.
SqljConnCacheBean does not store the connection context instances it creates.
Example: SQLJ JSP Page Using SqljConnCacheBean

The following program, SQLJSelectInto.sqljsp, demonstrates the use of
SqljConnCacheBean, its ContextClass bean property, and its getContext() method:
<%@ page language="sqlj"
import="java.sql.*, oracle.sqlj.runtime.SqljConnCacheBean" %>
<jsp:useBean id="cbean" class="oracle.sqlj.runtime.SqljConnCacheBean"
scope="session">
<jsp:setProperty name="cbean" property="User" value="HR"/>
<jsp:setProperty name="cbean" property="Password" value="hr"/>
<jsp:setProperty name="cbean" property="URL"
value="jdbc:oracle:thin:@myhost:5221/myservice"/>
<jsp:setProperty name="cbean" property="ContextClass"
value="sqlj.runtime.ref.DefaultContext"/>
</jsp:useBean>
<HTML>
<HEAD> <TITLE> The SQLJSelectInto JSP </TITLE> </HEAD>
<BODY BGCOLOR=white>
<% String empno = request.getParameter("employee_id");
if (empno != null) { %>
<H3> Employee # <%=empno %> Details: </H3>
<% String ename = null; double sal = 0.0; String hireDate = null;
StringBuffer sb = new StringBuffer();
sqlj.runtime.ref.DefaultContext ctx=null;
try {
// Make the Connection
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ctx = (sqlj.runtime.ref.DefaultContext) cbean.getContext();

}
try {
#sql [ctx] { SELECT first_name, salary, TO_CHAR(hire_date, 'DD-MON-
YYYY')
INTO :ename, :sal, :hireDate
FROM HR.employees WHERE UPPER(employee_id) =
UPPER(:empno)
};
sb.append("<BLOCKQUOTE><BIG><B><PRE>\n");
sb.append("Name : " + ename + "\n");
sb.append("Salary : " + sal + "\n");
sb.append("Date hired : " + hireDate);
sb.append("</PRE></B></BIG></BLOCKQUOTE>");
} catch (java.sql.SQLException e) {
sb.append("<P> SQL error: <PRE> " + e + " </PRE> </P>\n");
} finally {
if (ctx!= null) ctx.close();
}
%>
<H3><%=sb.toString()%></H3>
<%}
%>
<B>Enter an employee number:</B>
<FORM METHOD=get>
<INPUT TYPE="text" NAME="empno" SIZE=10>
<INPUT TYPE="submit" VALUE="Ask Oracle");
</FORM>
</BODY>
</HTML>
Note:
This example uses the ContextClass property for illustrative purposes.
However, be aware that DefaultContext is the default value anyway and
if you want to use DefaultContext, then the value of ContextClass is
irrelevant, if you use getDefaultContext() instead of getContext().
8.1.11 SQLJ Support for Global Transactions

A distributed transaction, sometimes referred to as a global transaction, is a set of
two or more related transactions that must be managed in a coordinated way. The
transactions that constitute a distributed transaction might be in the same database,
but more typically are in different databases and often in different locations. Each
individual transaction of a distributed transaction is referred to as a transaction branch.
The X/Open Distributed Transaction Processing (DTP) architecture defines a standard
architecture that enables multiple but related transactions belonging to the same
resource manager or different resource managers to work as a single unit. It
coordinates the work between an application program (AP) and a resource manager
(RM) into global transactions. Either all the transactions are committed or rolled back.
The Oracle XA library is an external interface that enables transaction managers
other than Oracle server to coordinate global transactions. XA library use supports
non-Oracle resource managers, in distributed transactions. This is particularly useful
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in transactions between several databases and resources. The implementation of the

Oracle XA library conforms to the X/Open Distributed Transaction Processing (DTP)
software architecture's XA interface specification. The Oracle XA Library is installed as
part of Oracle Database Enterprise Edition.
Note:
• JDBC provides several classes and interfaces to support XA. The

OracleXADataSource implements the XADataSource interface. The
OracleXADatasource is a factory for XA connections. For more
information refer to Oracle Database JDBC Developer’s Guide.
• This document clearly specifies the methods supported by SQLJ
to form a Connection Context in a XA application. To form the
connection context, SQLJ uses the JDBC connection formed from the
OracleXADataSource.
Figure 8-1 Global Transaction
Application Program (AP)
Transaction Native Interface

Manager
(TM) Resource
Manager Resource
(RM) Manager
(RM)
Oracle
Database Other
Resource
Following is an example of Distributed Transaction Processing (DTP) model:

The transaction manager is an external middle tier component residing outside
Oracle Database. It provides an API for specifying the boundaries of the transaction
and manages commit and recovery. The TM implements a two-phase commit engine
to provide an all-or-none semantics across distributed RMs.
A resource manager controls a shared, recoverable resource that can be returned to
a consistent state after a failure. For example, Oracle is a resource manager.
The javax.sql.XADataSource interface outlines standard functionality of XA data
sources. An XA data source is a factory for XA connections. Oracle JDBC
implements the XADataSource interface though the OracleXADatasource class. The
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getConnection( ) method of the OracleXADatasource class returns an XA connection

to the underlying data source. In SQLJ, connections to the database can be obtained
through the DefaultContext class or the ConnectionContext class. For multiple
connections that use different SQL entities, it is advantageous to use connection
context declarations to define additional connection context classes.
The code snippet shows how to create an XADatasource first and then a JDBC
connection from the datasource through the following steps:
• Start XA Resource1
• Start XA Resource2
• Perform DML operations with the first Connection object
• End XA Resource1
• End XA Resource2
• Prepare Resource1
• Prepare Resource2
• Commit 1
• Commit 2
Note:
The following is not a complete example and contains only relevant codes to
create and use an XADatasource.
Example: Creating an XADatasource and using it to create a JDBC connection

import javax.sql.*;
import javax.transaction.*;
import javax.transaction.xa.*;
...
import oracle.jdbc.driver.*;
import oracle.jdbc.xa.OracleXid;
import oracle.jdbc.xa.OracleXAException;
import oracle.jdbc.xa.client.*;
…………
#sql iterator Iterator2 (String job_id, String job_title);
#sql iterator Iterator3 (String region_id, String region_name);
…………
class XA3mod{
public static void main (String args [])throws SQLException{
try{
/*create an XADataSource instance*/
OracleXADataSource oxds = new OracleXADataSource();
oxds.setURL(url);
oxds.setUser("hr");
oxds.setPassword("hr");
/*get an XA connection to the underlying data source*/
javax.sql.XAConnection pc1 = oxds.getXAConnection();
/*use the same data source */
javax.sql.XAConnection pc2 = oxds.getXAConnection();
/*get the Physical Connections*/
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java.sql.Connection conn1 = pc1.getConnection();

java.sql.Connection conn2 = pc2.getConnection();
/*an application may access data through multiple database connections. Each
database connection is enlisted
with the transaction manager as a transactional resource. The transaction
manager obtains an XAResource
for each connection participating in a global transaction */
XAResource oxar1 = pc1.getXAResource();
XAResource oxar2 = pc2.getXAResource();
/*create the Xids With the Same Global Ids. The Xid interface is a Java mapping
of the X/Open transaction
identifier XID structure*/
Xid xid1 = createXid(1);
Xid xid2 = createXid(2);
/*start the Resources. This would start work on behalf of a transaction branch
specified in xid1 and xid2.
The transaction manager uses the start method to associate the global
transaction with the resource,
and it uses the end method to disassociate the transaction from the resource */
oxar1.start (xid1, XAResource.TMNOFLAGS);
oxar2.start (xid2, XAResource.TMNOFLAGS);
/*Do something with conn1 */
DoSomeWork (conn1);
/*END both the branches */
xar1.end(xid1, XAResource.TMSUCCESS);
xar2.end(xid2, XAResource.TMSUCCESS);
/*Prepare the RMs. The Oracle XA library interface follows the two-phase commit
protocol. Preparing the transactions
is the first step in this protocol. The two phase commit protocol is explained
in detail in the glossary section. */
int prp1 = oxar1.prepare (xid1);
int prp2 = oxar2.prepare (xid2);
boolean do_commit = true;
if(!((prp1==XAResource.XA_OK)||(prp1==XAResource.XA_RDONLY)))
do_commit = false;
if(!((prp2==XAResource.XA_OK)||(prp2==XAResource.XA_RDONLY)))
do_commit = false;
/*issue a commit on all transactions only if all the transactions completed
without and errors. Rollback even
if a single transaction failed.*/
if (prp1 == XAResource.XA_OK)
if (do_commit)
oxar1.commit (xid1, false);
else
oxar1.rollback (xid1);
if (prp2 == XAResource.XA_OK)
if (do_commit)
oxar2.commit (xid2, false);
else
oxar2.rollback (xid2);
/* close connections */
conn1.close(); conn1 = null;
conn2.close(); conn2 = null;
pc1.close(); pc1 = null;
pc2.close(); pc2 = null;
} catch (XAException xae){
if (xae instanceof OracleXAException) {
System.out.println("XA Error is " + ((OracleXAException)xae).getXAError());
System.out.println("SQL Error is " +((OracleXAException)xae).getOracleError());
}
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}
} //end class
The following examples explain the different SQLJ methods that can accept a JDBC
connection obtained from an OracleXADatasource.
Using Oracle.connect( ) method with a JDBC connection obtained from an XA

Datasource:
private static void DoSomeWork (java.sql.Connection conn) throws SQLException{
String chr = "XA_CERT";
Oracle.connect(conn);
#sql {insert into xa_test values (1,:chr)};
try{
Iterator3 iter = null;
#sql iter = {SELECT id,name FROM xa_test};
while (iter.next( )){
System.out.print(iter.id());
System.out.print(" ");
System.out.println(iter.name());
}
}
catch (Exception e){
System.out.println(e);
}
}
Using Oracle.getConnection( ) method with a JDBC connection obtained from an

XA Datasource
DefaultContext ctx = Oracle.getConnection(conn);
#sql [ctx] {insert into xa_test values (1,:chr)};
try{
#sql [ctx] iter = {SELECT id,name FROM xa_test};
}
}
}
}
Using DefaultContext Constructor with a JDBC connection obtained from an XA

Datasource
DefaultContext ctx = new DefaultContext(conn)
try{
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}
}
}
}
Using DefaultContext Constructor by passing a ConnectionContext to it. The

ConnectionContext is created through the JDBC connection obtained from an
XA Datasource
MyContext myctx1= new MyContext (conn);
DefaultContext ctx = new DefaultContext(myctx1);
try{
}
}
}
}
Using Oracle.connect( ) method by passing a ConnectionContext to it. The

ConnectionContext is created through the JDBC connection obtained from an
XA Datasource
Oracle.connect(myctx1);
#sql {insert into xa_test values (1,:chr)};
try{
#sql iter = {SELECT id,name FROM xa_test};
}
}
}
}
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Using Oracle. getConnection( ) method by passing a ConnectionContext to it.

The ConnectionContext is created through the JDBC connection obtained from
an XA Datasource
DefaultContext ctx = Oracle.getConnection(myctx1);
try{
}
}
}
}
The setDefaultContext( ) method of the DefaultContext class can also be used to

set a context which was created through the JDBC connection obtained from an
XA Datasource
DefaultContext.setDefaultContext(ctx);
Using the ConnectionContext constructor by passing a JDBC connection

obtained from an XA Datasource
#sql [myctx1] {insert into xa_test values (1,:chr)};
try{
#sql [myctx1] iter = {SELECT id,name FROM xa_test};
}
}
}
}
Using the ConnectionContext constructor by passing a ConnectionContext to it.

The ConnectionContext is created through the JDBC connection obtained from
an XA Datasource
MyContext myctx= new MyContext (conn);
MyContext myctx1= new MyContext (myctx);
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#sql [myctx1] {insert into xa_test values (1,:chr)};

try{
#sql [myctx1] iter = {SELECT id,name FROM xa_test};
}
}
}
}
8.1.12 Connecting to PDBs

A pluggable database (PDB) enables an Oracle Database to contain a portable
collection of schemas, schema objects, and nonschema objects that appears to an
Oracle client as a separate database. A multitenant container database (CDB) is an
Oracle Database that includes one or more PDBs. SQLJ applications can connect to a
PDB using a service, whose PLUGGABLE DATABASE property is set to the relevant PDB.
See Also:
Oracle Database Backup and Recovery User’s Guide for more information
about configuring the services to connect to various pluggable databases
8.2 Execution Contexts

An execution context is an instance of the sqlj.runtime.ExecutionContext class
and provides a context in which SQL operations are executed. An execution context
instance is associated either implicitly or explicitly with each SQL operation in your
SQLJ application.
The ExecutionContext class contains methods for the following features:
• Execution control operations modify the semantics of subsequent SQL operations.

• Execution status operations describe the results of the most recent SQL operation.
• Execution cancellation operations terminate the SQL operation that is currently
executing.
• Update-batching operations enable and disable update batching, set the batch
limit, and get update counts.
• Savepoint operations set a savepoint, roll back to a savepoint, and release a
savepoint.
• Closure operations close the execution context instance to avoid resource
leakage.
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Note:
There is only one execution context class, unlike connection context classes
where you declare additional classes as desired. Every execution context is
an instance of the ExecutionContext class. So while the term connection
context usually refers to a class that you have declared, the term execution
context always refers to an instance of the ExecutionContext class. This
document specifies connection context class, connection context instance,
and execution context instance to avoid confusion.

• Relation of Execution Contexts to Connection Contexts
• Creating and Specifying Execution Context Instances
• Execution Context Synchronization
• Execution Context Methods
• Relation of Execution Contexts to Multithreading
8.2.1 Relation of Execution Contexts to Connection Contexts

Each connection context instance implicitly has its own default execution context
instance, which you can retrieve by using the getExecutionContext() method of the
A single execution context instance will be sufficient for a connection context instance
except in the following circumstances:
• You are using multiple threads with a single connection context instance.
When using multithreading, each thread must have its own execution context
instance.
• You want to use different SQL execution control operations on different SQLJ
statements that use the same connection context instance.
• You want to retain different sets of SQL status information from multiple SQL
operations that use the same connection context instance.
As you execute successive SQL operations that use the same execution context
instance, the status information from each operation overwrites the status
information from the previous operation.
Although execution context instances might appear to be associated with connection
context instances (given that each connection context instance has a default execution
context instance, and you can specify a connection context instance and an execution
context instance together for a particular SQLJ statement), they actually operate
independently. You can use different execution context instances in statements that
use the same connection context instance, and vice versa.
For example, it is useful to use multiple execution context instances with a single
connection context instance if you use multithreading, with a separate execution
context instance for each thread. And you can use multiple connection context
instances with a single explicit execution context instance if your program is single-
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threaded and you want the same set of SQL control parameters to apply to all the
connection context instances.
See Also:
"Execution Context Methods"
To use different execution context instances with a single connection context instance,
you must create additional instances of the ExecutionContext class and specify them
appropriately with your SQLJ statements.
8.2.2 Creating and Specifying Execution Context Instances

To use an execution context instance other than the default with a given connection
context instance, you must construct another execution context instance. There are no
input parameters for the ExectionContext constructor. For example:
ExecutionContext myExecCtx = new ExecutionContext();
You can then specify this execution context instance for use with any particular SQLJ
statement, much as you would specify a connection context instance. The general
syntax is as follows:
#sql [<conn_context><, ><exec_context>] { SQL operation };
For example, if you also declare and instantiate a connection context class,
MyConnCtxClass, and create an instance, myConnCtx, then you can use the following
statement:
#sql [myConnCtx, myExecCtx] { DELETE FROM employees WHERE salary > 30000 };
You can subsequently use different execution context instances with myConnCtx or
different connection context instances with myExecCtx.
You can optionally specify an execution context instance while using the default
connection context instance, as follows:
#sql [myExecCtx] { DELETE FROM employees WHERE salary > 30000 };
Note:
• If you specify a connection context instance without an execution context

instance, then the default execution context instance of that connection
context instance is used.
• If you specify an execution context instance without a connection context
instance, then the execution context instance is used with the default
connection context instance of your application.
• If you specify no connection context instance and no execution context
instance, then SQLJ uses the default connection and its default
execution context instance.
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8.2.3 Execution Context Synchronization

ExecutionContext methods are all synchronized methods. Therefore, for ISO
standard code generation, anytime a statement tries to use an execution context
instance already in use, the second statement will be blocked until the first statement
completes.
In a client application, this typically involves multithreading situations. A thread that
tries to use an execution context instance currently in use by another thread will
be blocked. To avoid such blockage, you must specify a separate execution context
instance for each thread that you use.
See Also:
"Multithreading in SQLJ"
The preceding discussion does not apply for default Oracle-specific code generation.
For performance reasons, SQLJ performs no additional synchronization against
ExecutionContext instances for Oracle-specific generated code. Therefore, you are
responsible for ensuring that the same execution context instance will not be used by
more than one thread. If multiple threads use the same execution context, then your
application, rather than blocking, will experience errors such as incorrect results or
NullPointer exceptions.
Another exception to the discussion is for recursion, which is encountered only in the
server. Multiple SQLJ statements in the same thread are allowed to simultaneously
use the same execution context instance if this situation results from recursive calls.
An example of this is where a SQLJ stored procedure or function has a call to another
SQLJ stored procedure or function. If both use the default execution context instance,
as is typical, then the SQLJ statements in the second procedure will use this execution
context while the SQLJ call statement from the first procedure is also still using it. This
is allowed.
8.2.4 Execution Context Methods

The following sections list public methods of the ExecutionContext class and provide
an example:
• Status Methods
• Control Methods
• Cancellation Method
• Update Batching Methods
• Savepoint Methods
• Close Method
• Example: Using ExecutionContext Methods
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8.2.4.1 Status Methods

Use the following methods of an execution context instance to obtain status
information about the most recent SQL operation that completed using that instance:
• SQLWarning getWarnings(): Returns a java.sql.SQLWarning object containing
the first warning reported by the most recent SQL operation that completed
using this execution context instance. Warnings are returned in a chain. Use the
getWarnings() method of the execution context instance to get the first warning,
then use the getNextWarning() method of each SQLWarning object to get the next
warning. The chain contains all warnings generated during the execution of the
SQL operation.
• int getUpdateCount(): Except when update batching is enabled, this returns
an int value specifying the number of rows updated by the last SQL operation
that completed using this execution context instance. Zero (0) is returned if the
last SQL operation was not a data manipulation language (DML) statement. The
QUERY_COUNT constant is returned, if the last SQL operation produced an iterator
or result set. The EXCEPTION_COUNT constant is returned, if the last SQL operation
terminated before completing execution or if no operation has yet been attempted
using this execution context instance.
For batch-enabled applications, the value returned by getUpdateCount() would be
one of several batch-related constant values: NEW_BATCH_COUNT, ADD_BATCH_COUNT,
or EXEC_BATCH_COUNT.
See Also:
"Execution Context Update Counts"
8.2.4.2 Control Methods

Use the following methods of an execution context instance to control the operation
of future SQL operations executed using that instance (operations that have not yet
started):
• int getMaxFieldSize(): Returns an int value specifying the maximum amount
of data (in bytes) that would be returned from a SQL operation subsequently,
using this execution context instance. This applies only to columns of the BINARY,
VARBINARY, LONGVARBINARY, CHAR, VARCHAR, or LONGVARCHAR type.
By default this parameter is set to 0, meaning there is no size limit.
• setMaxFieldSize(int): Takes an int value as input to modify the maximum field-
size.
• int getMaxRows(): Returns an int value specifying the maximum number of rows
that can be contained by any SQLJ iterator or JDBC result set created using this
execution context instance. If the limit is exceeded, then the excess rows are
silently dropped without any error report or warning.
By default, this parameter is set to 0, meaning there is no row limit.
• setMaxRows(int): Takes an int value as input to modify the maximum row value.
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• int getQueryTimeout(): Returns an int value specifying the timeout interval, in

seconds, for any SQL operation that uses this execution context instance. If a SQL
operation exceeds this limit, then a SQL exception is thrown.
By default, this parameter is set to 0, meaning there is no query timeout limit.
• setQueryTimeout(int): Takes an int value as input to modify the query timeout
limit.
• int getFetchSize(): Retrieves the number of rows that is the current fetch
size for iterator objects generated from this ExecutionContext object. If this
ExecutionContext object has not set a fetch size by calling setFetchSize(), then
the value returned is 0. If this ExecutionContext object has set a non-negative
fetch size by calling the method setFetchSize(), then the return value is the fetch
size specified on setFetchSize().
• setFetchSize(int): Gives the SQLJ run time a hint as to the number of rows
that should be fetched when more rows are needed. The number of rows
specified affects only iterator objects created using this ExecutionContext object.
Specifying zero means that an implementation-dependent default value will be
used for the fetch size.
• int getFetchDirection(): Retrieves the default direction for fetching data, for
scrollable iterator objects that are generated from this ExecutionContext object. If
this ExecutionContext object has not set a fetch direction by calling the method
setFetchDirection(), then the return value is FETCH_FORWARD.
• setFetchDirection(int): Gives the SQLJ run time a hint as to the direction in
which rows of scrollable iterator objects are processed. The hint applies only to
scrollable iterator objects that are created using this ExecutionContext object.
The default value is:
sqlj.runtime.ResultSetIterator.FETCH_FORWARD.
This method throws a SQLException if the given direction is not one of

FETCH_FORWARD, FETCH_REVERSE, or FETCH_UNKNOWN (int constants).
8.2.4.3 Cancellation Method

Use the following method to cancel SQL operations in a multithreading environment or
to cancel a pending statement batch if update batching is enabled:
• cancel(): In a multithreading environment, use this method in one thread to
cancel a SQL operation currently executing in another thread. It cancels the most
recent operation that has started but not completed, using this execution context
instance. This method has no effect if no statement is currently being executed
using this execution context instance.
In a batch-enabled environment, use this to cancel a pending statement batch.
The batch is emptied, and none of the statements in the batch are executed. After
you cancel a batch, the next batchable statement encountered will be added to a
new batch.
See Also:
"Canceling a Batch"
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8.2.4.4 Update Batching Methods

Use the following methods to control update batching if you want your application to
use that performance enhancement feature:
• int[] executeBatch(): Executes the pending statement batch, returning an array
of int update counts.
• int getBatchLimit(): Returns an int value indicating the current batch limit. If
there is a batch limit, then a pending batch is implicitly executed once it contains
that number of statements.
By default, the batch limit is set to the ExecutionContext static constant value
UNLIMITED_BATCH, meaning there is no batch limit.
• int[] getBatchUpdateCounts(): Returns an array of int update counts for the
last batch executed. This method is useful in situations where the batch was
executed implicitly.
• boolean isBatching(): Returns a boolean value indicating whether update
batching is enabled.
This does not indicate whether there is currently a pending batch, but you can use
the getUpdateCount() method to see whether a batch has been newly created,
added to, or executed.
• setBatching(boolean): Takes a boolean value to enable update batching.
Update batching is disabled by default.
• setBatchLimit(int): Takes a positive, nonzero int value as input to set the
current batch limit. Two special values you can assign are UNLIMITED_BATCH,
which means there is no limit, and AUTO_BATCH, which lets the SQLJ run time
to dynamically determine a batch limit.
See Also:
8.2.4.5 Savepoint Methods

The Oracle SQLJ implementation supports JDBC 3.0 savepoints. Savepoints are
stored in the ExecutionContext instance, and the following public methods exist to
support the SQLJ savepoint statements:
• Object oracleSetSavepoint(ConnectionContextImpl, String)
Register a savepoint and return the savepoint as an Object instance.
This method takes the connection context as an instance of the
sqlj.runtime.ref.ConnectionContextImpl class and a string that specifies the
savepoint name.
The Oracle SQLJ implementation instantiates a savepoint as an instance of
the oracle.jdbc.OracleSavepoint class, which extends the java.sql.Savepoint
interface.
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• void oracleRollbackToSavepoint (ConnectionContextImpl, Object)

Roll back changes to the specified savepoint. This method takes the connection
context as an instance of ConnectionContextImpl and the savepoint as an Object
instance.
• void oracleReleaseSavepoint(ConnectionContextImpl, Object)
Release the specified savepoint. This method takes the connection context as an
instance of ConnectionContextImpl and the savepoint as an Object instance.
You will generally use SQLJ savepoint statements instead of using these methods
directly.
8.2.4.6 Close Method

The Oracle SQLJ implementation provides extended functionality with a close()
method for the ExecutionContext class:
• close(): To avoid resource leakage, use this method if the following

circumstances are all true:
– You are using the Oracle-specific code generation.
– You explicitly created and used the ExecutionContext instance, instead of
using the default instance available through the connection context instance.
– You are not issuing SQLJ rollback or commit statements explicitly using the
ExecutionContext instance:
#sql [ec] { COMMIT };
#sql [ec] { ROLLBACK };
– You are not calling executeBatch() on the ExecutionContext instance.
Under this set of circumstances, a batchable statement might remain open on the
ExecutionContext instance and over time you may run out of database cursors.
To avoid this, use the close() method as in the following example:
Execution Context ec = new ExecutionContext();
...
try {
...
#sql [ec] { SQL operation };
...
} finally { ec.close(); }
Note:
When an execution context instance is associated with a connection context
instance, instead of being declared explicitly, then closing the connection
context instance, with or without closing the underlying JDBC connection,
will automatically close any statement remaining on the execution context
instance.
8.2.4.7 Example: Using ExecutionContext Methods

The following code demonstrates the use of some ExecutionContext methods:
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ExecutionContext execCtx =
DefaultContext.getDefaultContext().getExecutionContext();
// Wait only 3 seconds for operations to complete

execCtx.setQueryTimeout(3);
// delete using execution context of default connection context

#sql { DELETE FROM employees WHERE salary > 10000 };
System.out.println
("removed " + execCtx.getUpdateCount() + " employees");
8.2.5 Relation of Execution Contexts to Multithreading

Do not use multiple threads with a single execution context. If you do, and two SQLJ
statements try to use the same execution context simultaneously, then the second
statement will be blocked until the first statement completes. Furthermore, status
information from the first operation will likely be overwritten before it can be retrieved.
Therefore, if you are using multiple threads with a single connection context instance,
then you should take the following steps:
1. Instantiate a unique execution context instance for use with each thread.
2. Specify execution contexts with your #sql statements so that each thread uses its
own execution context.
If you are using a different connection context instance with each thread, then no
instantiation and specification of execution context instances is necessary, because
each connection context instance implicitly has its own default execution context
instance.
Note:
For performance reasons, SQLJ performs no additional synchronization
against ExecutionContext instances for Oracle-specific generated code.
Therefore, you are responsible for ensuring that the same execution context
instance will not be used by more than one thread. If multiple threads use
the same execution context, then your application, rather than blocking, will
experience errors such as incorrect results or NullPointer exceptions.
8.3 Multithreading in SQLJ

This section discusses SQLJ support and requirements for multithreading and the
relation between multithreading and execution context instances.
You can use SQLJ in writing multithreaded applications. However, any use of
multithreading in your SQLJ application is subject to the limitations of your JDBC driver
or proprietary database access vehicle. This includes any synchronization limitations.
You are required to use a different execution context instance for each thread. You can
accomplish this in one of two ways:
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• Specify connection context instances for your SQLJ statements such that a
different connection context instance is used for each thread. Each connection
context instance automatically has its own default execution context instance.
• If you are using the same connection context instance with multiple threads,
then declare additional execution context instances and specify execution context
instances for your SQLJ statements such that a different execution context
instance is used for each thread.
See Also:
"Specifying Connection Context Instances and Execution Context Instances"
If you are using one of Oracle JDBC drivers, then multiple threads can use the
same connection context instance, if desired, as long as different execution context
instances are specified and there are no synchronization requirements directly visible
to you. However, note that data access is sequential. Only one thread is accessing
data at any given time. Synchronization refers to the control flow of the various stages
of the SQL operations executing through your threads. For example, each statement
can bind input parameters, then execute, and then bind output parameters. With some
JDBC drivers, special care must be taken not to intermingle these stages.
For ISO standard code generation, if a thread attempts to execute a SQL operation
that uses an execution context that is in use by another operation, then the thread
is blocked until the current operation completes. If an execution context were shared
between threads, then the results of a SQL operation performed by one thread would
be visible in the other thread. If both threads were executing SQL operations, then
a race condition might occur. The results of an execution in one thread might be
overwritten by the results of an execution in the other thread before the first thread had
processed the original results. This is why multiple threads are not allowed to share an
execution context instance.
Note:
The preceding paragraph does not apply if you use default Oracle-specific
code generation. For performance reasons, SQLJ performs no additional
synchronization against ExecutionContext instances for Oracle-specific
generated code. Therefore, you are responsible for ensuring that the same
execution context instance will not be used by more than one thread. If
multiple threads use the same execution context, then your application,
rather than blocking, will experience errors such as incorrect results or
NullPointer exceptions.
Multithreading: MultiThreadDemo.sqlj
The following is an example of a SQLJ application using multithreading. A ROLLBACK
operation is executed before closing the connection, so the data is not permanently
altered.
import java.sql.SQLException;
import java.util.Random;
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import sqlj.runtime.ExecutionContext;
/**
Each instance of MultiThreadDemo is a thread that gives all employees
a raise of some ammount when run. The main program creates two such
instances and computes the net raise after both threads have completed.
**/
class MultiThreadDemo extends Thread
{
double raise;
static Random randomizer = new Random();
public static void main (String args[])

{
try {
// set the default connection to the URL, user, and password
Oracle.connect(MultiThreadDemo.class, "connect.properties");
double avgStart = calcAvgSal();
MultiThreadDemo t1 = new MultiThreadDemo(250.50);
MultiThreadDemo t2 = new MultiThreadDemo(150.50);
t1.start();
t2.start();
t1.join();
t2.join();
double avgEnd = calcAvgSal();
System.out.println("average salary change: " + (avgEnd - avgStart));
}
try { #sql { ROLLBACK }; Oracle.close(); } catch (SQLException e) { }
}
static double calcAvgSal() throws SQLException
{
double avg;
#sql { SELECT AVG(salary) INTO :avg FROM employees };
return avg;
}
MultiThreadDemo(double raise)
{
this.raise = raise;
}
public void run()
{
// Since all threads will be using the same default connection
// context, each run uses an explicit execution context instance to
// avoid conflict during execution
try {
delay();
ExecutionContext execCtx = new ExecutionContext();
#sql [execCtx] { UPDATE EMPLOYEES SET salary = salary + :raise };
int updateCount = execCtx.getUpdateCount();
System.out.println("Gave raise of " + raise + " to " +
updateCount + " employees");
System.err.println("error updating employees: " + e);
}
}
// delay is used to introduce some randomness into the execution order
private void delay()
{
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Iterator Class Implementation and Advanced Functionality
try {
sleep((long)Math.abs(randomizer.nextInt()/10000000));
} catch (InterruptedException e) {}
}
}
8.4 Iterator Class Implementation and Advanced

Functionality
This section discusses how iterator classes are implemented and what additional
functionality is available beyond the essential methods. The following topics are
covered:
• Implementation and Functionality of Iterator Classes
• Using the IMPLEMENTS Clause in Iterator Declarations
• Support for Extending Iterator Classes
• Result Set Iterators
• Scrollable Iterators
8.4.1 Implementation and Functionality of Iterator Classes

Any named iterator class you declare will be generated by the SQLJ translator
to implement the sqlj.runtime.NamedIterator interface. Classes implementing the
NamedIterator interface have functionality that maps iterator columns to database
columns by name, not by position.
Any positional iterator class you declare will be generated by the SQLJ translator
to implement the sqlj.runtime.PositionedIterator interface. Classes implementing
the PositionedIterator interface have functionality that maps iterator columns to
database columns by position, not by name.
Both the NamedIterator interface and the PositionedIterator interface, and
therefore all generated SQLJ iterator classes as well, implement or extend the
sqlj.runtime.ResultSetIterator interface.
The ResultSetIterator interface specifies the following methods for all SQLJ
iterators:
• close(): Closes the iterator.
• ResultSet getResultSet(): Extracts the underlying JDBC result set from the
iterator.
• boolean isClosed(): Determines if the iterator has been closed.
• boolean next(): Moves to the next row of the iterator, returning true if there is a
valid next row to go to.
The PositionedIterator interface adds the following method specification for
positional iterators:
• boolean endFetch(): Determines if you have reached the last row of a positional
iterator.
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Use the next() method to advance through the rows of a named iterator and accessor
methods to retrieve the data. The SQLJ generation of a named iterator class defines
an accessor method for each iterator column, where each method name is identical to
the corresponding column name. For example, if you declare a name column, then a
name() method will be generated.
Use a FETCH INTO statement together with the endFetch() method to advance through
the rows of a positional iterator and retrieve the data. A FETCH INTO statement
implicitly calls the next() method. Do not explicitly use the next() method in a
positional iterator unless you are using the special FETCH CURRENT syntax. The FETCH
INTO statement also implicitly calls accessor methods that are named according to
iterator column numbers. The SQLJ generation of a positional iterator class defines an
accessor method for each iterator column, where each method name corresponds to
the column position.
See Also:
\
Use the close() method to close any iterator once you are done with it. The
getResultSet() method is central to SQLJ-JDBC interoperability.
See Also:
Note:
Alternatively, you can use a ResultSetIterator instance or a
ScrollableResultSetIterator instance directly as a weakly typed
iterator. (ScrollableResultSetIterator extends ResultSetIterator.) This
is convenient if you are interested only in converting it to a JDBC result set
and you do not need named or positional iterator functionality. You can also
access it through SQLJ FETCH CURRENT syntax.
8.4.2 Using the IMPLEMENTS Clause in Iterator Declarations

There may be situations where it will be useful to implement an interface in your
iterator declaration. For example, you may have an iterator class where you want to
restrict access to one or more columns. A named iterator class generated by SQLJ
has an accessor method for each column in the iterator. If you want to restrict access
to certain columns, you can create an interface with only a subset of the accessor
methods, then expose instances of the interface type to the user instead of exposing
instances of the iterator class type.
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For example, assume you are creating a named iterator of employee data, with
columns ENAME (employee name), EMPNO (employee number), and SAL (salary).
Accomplish this as follows:
#sql iterator EmpIter (String ename, int empno, float sal);
This generates a class EmpIter with ename(), empno(), and sal() accessor methods.
Assume, though, that you want to prevent access to the SAL column. You can create
an EmpIterIntfc interface that has ename() and empno() methods, but no sal()
method. Then you can use the following iterator declaration instead of the preceding
declaration (presuming EmpIterIntfc is in the mypackage package):
#sql iterator EmpIter implements mypackage.EmpIterIntfc
(String emame, int empno, float sal);
Then if you code your application so that users can access data only through
EmpIterIntfc instances, then they will not have access to the SAL column.
8.4.3 Support for Extending Iterator Classes

SQLJ supports the ability to extend iterator classes. This feature can be very useful in
allowing you to add functionality to your queries and query results.
The one key requirement of an iterator subclass is that you must supply a public
constructor that takes an instance of sqlj.runtime.RTResultSet as input. The SQLJ
run time will call this constructor in assigning query results to an instance of your
subclass. Beyond that, you provide functionality as you choose.
You can continue to use functionality of the original iterator class (the superclass of
your subclass). For example, you can advance through query results by calling the
super.next() method.
8.4.4 Result Set Iterators

You may have situations where you do not require the strongly typed functionality of a
SQLJ iterator.
For such circumstances, you can directly use instances of the
sqlj.runtime.ResultSetIterator type to receive query data, so that you are
not required to declare a named or positional iterator class. Alternatively, you
can use the sqlj.runtime.ScrollableResultSetIterator type, which extends
ResultSetIterator. This enables you to use SQLJ scrollable iterator functionality.
In using a result set iterator instead of a strongly typed iterator, you are trading the
strong type-checking of the SQLJ SELECT operation for the convenience of not having
to declare an iterator class.
The ResultSetIterator interface underlies all named and positional iterator classes
and specifies the getResultSet() and close() methods. If you want to use SQLJ
to process a result set iterator instance, then use a ScrollableResultSetIterator
instance and the FETCH CURRENT syntax.
If you want to use JDBC to process a result set iterator instance, you can use its
getResultSet() method and then process the underlying result set that you retrieve.
If you process a result set iterator through its underlying result set, you should close
the result set iterator, not the result set, when you are finished. Closing the result set
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iterator will also close the result set, but closing the result set will not close the result
set iterator.
Note:
The Oracle SQLJ implementation supports result set iterators for use as host
expressions and to represent cursors in FETCH statements. This functionality
was not supported prior to Oracle9i Database.
8.4.5 Scrollable Iterators

The ISO standard for SQLJ supports scrollable iterators, with functionality being
patterned after the JDBC 2.0 specification for scrollable JDBC result sets. The Oracle
SQLJ implementation supports this functionality.
See Also:
Declaring Scrollable Iterators

To characterize an iterator as scrollable, add the following clause to the iterator
declaration:
implements sqlj.runtime.Scrollable
This instructs the SQLJ translator to generate an iterator that implements the
Scrollable interface. Following is an example of a declaration of a named, scrollable
iterator:
#sql public static MyScrIter implements sqlj.runtime.Scrollable
The code that the SQLJ translator generates for the MyScrIter class will automatically
support all the methods of the Scrollable interface.
Scrollable Iterator Sensitivity

You can declare scrollable iterators, like scrollable result sets, to have sensitivity to
changes to the underlying data. By default, scrollable iterators in the Oracle SQLJ
implementation have a sensitivity setting of INSENSITIVE, meaning they do not
detect any such changes in the underlying data. However, you can use a with clause
to alter this setting. The following example expands an earlier example to specify
sensitivity:
#sql public static MyScrIter implements sqlj.runtime.Scrollable
with (sensitivity=SENSITIVE)
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Note:
The implements clause must precede the with clause.
The SQLJ standard also allows a setting of ASENSITIVE, which means accepting
the default sensitivity of the Database. But, in Oracle, if you set sensitivity to
ASENSITIVE, then it results in the default setting INSENSITIVE being used.
Given the preceding declaration, MyScrIter instances will be sensitive to data

changes, subject to factors such as the fetch size window.
See Also:
Oracle Database JDBC Developer's Guide for information about scrollable
result sets
The Scrollable Interface

This section documents some key methods of the sqlj.runtime.Scrollable
interface.
You can provide hints about the fetch direction to scrollable iterators. The following
methods are defined on scrollable iterators as well as on execution contexts. Use an
ExecutionContext instance to provide the default direction to be used in creation of
scrollable iterators.
• setFetchDirection(int): Gives the SQLJ run time a hint as to
the direction in which rows are processed. The direction should be
one of sqlj.runtime.ResultSetIterator.FETCH_FORWARD, FETCH_REVERSE, or
FETCH_UNKNOWN.
If you do not specify a value for the direction on the ExecutionContext, then
FETCH_FORWARD will be used as a default.
• int getFetchDirection(): Retrieves the current direction for fetching rows of
data (one of the integer constants described in the previous point).
There are also a number of scrollable iterator methods that will return information
about the current position of the iterator object in the underlying result set. All these
methods will return false whenever the result set underlying the iterator contains no
rows:
• boolean isBeforeFirst(): Indicates whether the iterator object is before the first
row in the result set.
• boolean isFirst(): Indicates whether the iterator object is on the first row of the
result set.
• boolean isLast(): Indicates whether the iterator object is on the last row of the
result set. Note that calling the isLast() method may be expensive, because the
JDBC driver may have to fetch ahead one row to determine whether the current
row is the last row in the result set.
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• boolean isAfterLast(): Indicates whether the iterator object is after the last row
in the result set.
Note:
Additional methods for navigation, also defined in the Scrollable interface,
are available as well.
Scrollable Named Iterators

Named iterators use navigation methods, defined in the Scrollable interface, to move
through the rows of a result set. As described earlier in this manual, nonscrollable
iterators have only the following method for navigation:
• boolean next(): Moves the iterator object to the next row in the result set.
See Also:
"Using Named Iterators"
Additional navigation methods are available for scrollable named iterators. These
methods function similarly to the next() method. In that they try to position the iterator
on an actual row of the result set. They return true if the iterator ends up on a valid
row and false if it does not. Additionally, if you attempt to position the iterator object
before the first row or after the last row in the result set, this leaves the iterator object
in the "before first" or "after last" position, respectively.
The following methods are supported:
• boolean previous(): Moves the iterator object to the previous row in the result
set.
• boolean first(): Moves the iterator object to the first row in the result set.
• boolean last(): Moves the iterator object to the last row in the result set.
• boolean absolute(int): Moves the iterator object to the given row number in the
result set. The first row is row 1, the second is row 2, and so on. If the given row
number is negative, then the iterator object moves to a row position relative to
the end of the result set. For example, calling absolute(-1) positions the iterator
object on the last row, absolute(-2) indicates the next-to-last row, and so on.
• boolean relative(int): Moves the iterator object a relative number of rows,
either positive or negative from the current position. Calling relative(0) is valid,
but does not change the iterator position.
• void beforeFirst(): Moves the iterator object to the front of the result set, before
the first row. This has no effect if the result set contains no rows.
• void afterLast(): Moves the iterator object to the end of the result set, after the
last row. This has no effect if the result set contains no rows.
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Note:
The beforeFirst() and afterLast() methods return void, because they
never place the iterator object on an actual row of the result set.
Scrollable Positional Iterators

General FETCH syntax for positional iterators was described earlier, in "Using Positional
Iterators". For example:
#sql { FETCH :iter INTO :x, :y, :z };
This is actually an abbreviated version of the following syntax:

#sql { FETCH NEXT FROM :iter INTO :x, :y, :z };
This suggests the pattern for alternatively moving to the previous, first, or last row
in the result set. Unfortunately, JDBC 2.0, after which the movement methods were
modeled, uses previous(). The FETCH syntax, which is patterned after SQL, employs
PRIOR. In case you forget this inconsistency, the Oracle Database 12c Release 1
(12.1) SQLJ translator will also accept FETCH PREVIOUS.
The syntax are:

#sql { FETCH PRIOR FROM :iter INTO :x, :y, :z };
#sql { FETCH FIRST FROM :iter INTO :x, :y, :z };
#sql { FETCH LAST FROM :iter INTO :x, :y, :z };
There is also syntax to pass a numeric value for absolute or relative movements, to
move to a particular (absolute) row, or to move forward or backward from the current
position. The syntax are:
#sql { FETCH ABSOLUTE :n FROM :iter INTO :x, :y, :z };
#sql { FETCH RELATIVE :n FROM :iter INTO :x, :y, :z };
Note:
In all of the preceding cases, the iterator endFetch() method returns true
whenever the FETCH fails to move to a valid row and retrieve values.
Note that you must use a host expression to specify the movement. You cannot simply
use a constant for the numeric value. Thus, instead of the following:
#sql { FETCH RELATIVE 0 FROM :iter INTO :x, :y, :z };
You must write the following:

#sql { FETCH RELATIVE :(0) FROM :iter INTO :x, :y, :z };
Incidentally, this command leaves the position of the iterator unchanged. If the iterator
is on a valid row, then the command just populates the variables.
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Note:
Alternatively, you can navigate through a scrollable positional iterator through
a combination of the navigation methods and the FETCH CURRENT syntax.
FETCH CURRENT Syntax: from JDBC Result Sets to SQLJ Iterators

Consider a situation where you have an existing JDBC program that you want to
rewrite in SQLJ with as little modification as possible.
Your JDBC result set will use only movement methods, such as next(), previous(),
absolute(), and so on. You can immediately model this in SQLJ through a named
iterator. However, this also implies that all columns of the SQL result set must have
a proper name. In practice, many columns of the result set, if not all, will require
introduction of alias names. This is unacceptable if the query text is to remain
untouched.
The alternative, to avoid change to the query source, is to define a positional iterator
type for the result set. However, this approach forces changes to the control-flow logic
of the program. Consider the following JDBC code sample:
ResultSet rs = ... // execute ...query...;
while (rs.next()) {
x := rs.getXxx(1); y:=rs.getXxx(2);
...process...
}
This translates along the following lines to SQLJ:

MyIter iter;
#sql iter = { ...query... };
while(true) {
#sql { FETCH :iter INTO :x, :y };
...process...
}
The transformations to the program logic will become even more difficult when
considering arbitrary movements on scrollable iterators. Because positional iterators
implement all the movement commands of named iterators, it is possible to exploit this
and use RELATIVE :(0) to populate variables from the iterator:
MyIter iter;
#sql iter = { ...query... };
while (iter.next()) {
#sql { FETCH RELATIVE :(0) FROM :iter INTO :x, :y };
...process...
}
Now, you can preserve both the original query and the original program logic.
Unfortunately, there still is one drawback to this approach. The MyIter iterator type
must implement the Scrollable interface, even if this property is not really needed. To
address this, the Oracle SQLJ implementation supports the following syntax extension:
#sql { FETCH CURRENT FROM :iter INTO :x, :y, :z };
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Given this syntax, you can rewrite the JDBC example in SQLJ for scrollable as well as
nonscrollable iterators:
AnyIterator ai;
#sql ai = { ...query... };
while (ai.next()) {
#sql { FETCH CURRENT FROM :ai INTO :x, :y };
...process...
}
Scrollable Result Set Iterators

Support in the Oracle SQLJ implementation for weakly typed result set iterators
includes a scrollable result set iterator type:
package sqlj.runtime;
public interface ScrollableResultSetIterator
extends ResultSetIterator
implements Scrollable
{ }
Because this type extends sqlj.runtime.ResultSetIterator, it supports the methods

described in "Result Set Iterators".
Because it also implements the sqlj.runtime.Scrollable interface, it supports the
methods described in "Scrollable Iterators" and "Scrollable Iterators".
Furthermore, scrollable result set iterators support the FETCH CURRENT syntax
described in "Scrollable Iterators".
Consider the following JDBC code:
Statement st = conn.createStatement("SELECT first_name, employee_id FROM
employees");
ResultSet rs = st.executeQuery();
while (rs.next()) {
x = rs.getString(1);
y = rs.getInt(2);
}
rs.close();
You can use a SQLJ result set iterator in writing equivalent code, as follows:
sqlj.runtime.ResultSetIterator rsi;
#sql rsi = { SELECT first_name, employee_id FROM employees };
while (rsi.next()) {
#sql { FETCH CURRENT FROM :rsi INTO :x, :y };
}
rsi.close();
To take advantage of scrollability features, you could also write the following code:
sqlj.runtime.ScrollableResultSetIterator srsi;
#sql srsi = { SELECT first_name, employee_id FROM employees };
srsi.afterLast();
while (srsi.previous()) {
#sql { FETCH CURRENT FROM :srsi INTO :x, :y };
}
srsi.close();
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Advanced Transaction Control
8.5 Advanced Transaction Control

SQLJ supports the SQL SET TRANSACTION statement to specify the access mode and
isolation level of any given transaction. Standard SQLJ supports READ ONLY and READ
WRITE access mode settings, but the Oracle JDBC implementation does not support
READ ONLY. However, you can set permissions to have the same effect. Supported
settings for isolation level are SERIALIZABLE, READ COMMITTED, READ UNCOMMITTED, and
REPEATABLE READ. However, the Oracle SQL implementation does not support READ
UNCOMMITTED or REPEATABLE READ.
READ WRITE is the default access mode in both standard SQL and the Oracle SQL
implementation. READ COMMITTED is the default isolation level in the Oracle SQL
implementation. SERIALIZABLE is the default in standard SQL.
The following sections provide details:

• SET TRANSACTION Syntax
• Access Mode Settings
• Isolation Level Settings
• Using JDBC Connection Class Methods
See Also:
"Basic Transaction Control"
8.5.1 SET TRANSACTION Syntax

The SQLJ SET TRANSACTION statement has the following syntax:
#sql { SET TRANSACTION <access_mode>, <ISOLATION LEVEL isolation_level> };
If you do not specify a connection context instance, then the statement applies to the
default connection. If you use SET TRANSACTION, then it must be the first statement in
a transaction, preceding any DML statements. In other words, the first statement since
your connection to the database or your most recent COMMIT or ROLLBACK.
In standard SQLJ, any access mode or isolation level you set will remain in effect
across transactions until you explicitly reset it at the beginning of a subsequent
transaction. In a standard SQLJ SET TRANSACTION statement, you can optionally
specify the isolation level first or only the access mode or only the isolation level.
Following are some examples:
#sql { SET TRANSACTION READ WRITE };
#sql { SET TRANSACTION ISOLATION LEVEL SERIALIZABLE };
#sql { SET TRANSACTION READ WRITE, ISOLATION LEVEL SERIALIZABLE };
#sql { SET TRANSACTION ISOLATION LEVEL READ COMMITTED, READ WRITE };
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Advanced Transaction Control
You can also specify a particular connection context instance for a SET TRANSACTION
statement, as opposed to having it apply to the default connection:
#sql [myCtxt] { SET TRANSACTION ISOLATION LEVEL SERIALIZABLE };
Note that in SQLJ, both the access mode and the isolation level can be set in a single
SET TRANSACTION statement. This is not true in other Oracle SQL tools, such as Server
Manager or SQL*Plus, where a single statement can set one or the other, but not both.
8.5.2 Access Mode Settings

The READ WRITE and READ ONLY access mode settings, where supported, have the
following functionality:
• READ WRITE (default): In a READ WRITE transaction, you are not allowed to update
the database. SELECT, INSERT, UPDATE, and DELETE are all legal.
• READ ONLY (also supported by the Oracle JDBC implementation): In a READ ONLY
transaction, you are not allowed to update the database. SELECT is legal, but
INSERT, UPDATE, DELETE, and SELECT FOR UPDATE are not.
8.5.3 Isolation Level Settings

The READ COMMITTED, SERIALIZABLE, READ UNCOMMITTED, and REPEATABLE READ
isolation level settings, where supported, have the following functionality:
• READ UNCOMMITTED: Dirty reads, nonrepeatable reads, and phantom reads are all
allowed.
• READ COMMITTED (default): Dirty reads are prevented, and nonrepeatable reads
and phantom reads are allowed. If the transaction contains DML statements that
require row locks held by other transactions, then any of the statements will block
until the row lock it needs is released by the other transaction.
• REPEATABLE READ: Dirty reads and nonrepeatable reads are prevented, and
phantom reads are allowed.
• SERIALIZABLE: Dirty reads, nonrepeatable reads, and phantom reads are all
prevented. Any DML statements in the transaction cannot update any resource
that might have had changes committed after the transaction began. Such DML
statements will fail.
A dirty read occurs when transaction B accesses a row that was updated by
transaction A, but transaction A later rolls back the updates. As a result, transaction B
sees data that was never actually committed to the database.
A nonrepeatable read occurs when transaction A retrieves a row, transaction B
subsequently updates the row, and transaction A later retrieves the same row again.
Transaction A retrieves the same row twice but sees different data.
A phantom read occurs when transaction A retrieves a set of rows satisfying a given
condition, transaction B subsequently inserts or updates a row such that the row now
meets the condition in transaction A, and transaction A later repeats the conditional
retrieval. Transaction A now sees an additional row. This row is referred to as a
phantom.
You can think of the four isolation level settings being in a progression:
SERIALIZABLE > REPEATABLE READ > READ COMMITTED > READ UNCOMMITTED
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SQLJ and JDBC Interoperability
If a desired setting is unavailable to you, such as REPEATABLE READ or READ

UNCOMMITTED if you use Oracle Database 12c Release 1 (12.1), use a greater setting
(one further to the left) to ensure having at least the level of isolation that you want.
See Also:
Oracle Database Development Guide
8.5.4 Using JDBC Connection Class Methods

You can optionally access and set the access mode and isolation level of a
transaction, using methods of the underlying JDBC connection instance of your
connection context instance. SQLJ code using these JDBC methods is not portable,
however.
Following are the Connection class methods for access mode and isolation level
settings:
• abstract int getTransactionIsolation(): Returns the current transaction
isolation level as one of the following constant values:
TRANSACTION_NONE TRANSACTION_READ_COMMITTED TRANSACTION_SERIALIZABLE
TRANSACTION_READ_UNCOMMITTED TRANSACTION_REPEATABLE_READ
• abstract void setTransactionIsolation(int): Sets the transaction isolation
level, taking as input one of the preceding constant values.
• abstract boolean isReadOnly(): Returns true if the transaction is READ ONLY.
Returns false if the transaction is READ WRITE.
• abstract void setReadOnly(boolean): Sets the transaction access mode to READ
ONLY if true is input. Sets the access mode to READ WRITE if false is input.
8.6 SQLJ and JDBC Interoperability

SQLJ statements are typically used for static SQL operations. Oracle Database
12c Release 1 (12.1) has extensions to support dynamic SQL as well, but another
alternative is to use JDBC code within your SQLJ application for dynamic operations,
which would be more portable. And there might be additional scenarios where using
JDBC code in your SQLJ application might be useful or even required. Because of
this, SQLJ enables you to use SQLJ and JDBC statements concurrently and provides
interoperability between SQLJ and JDBC constructs.
Two kinds of interactions between SQLJ and JDBC are particularly useful:
• Between SQLJ connection contexts and JDBC connections
• Between SQLJ iterators and JDBC result sets
See Also:
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• SQLJ Connection Context and JDBC Connection Interoperability
• SQLJ Iterator and JDBC Result Set Interoperability
8.6.1 SQLJ Connection Context and JDBC Connection Interoperability

SQLJ enables you to convert, in either direction, between SQLJ connection context
instances and JDBC connection instances.
Note:
When converting between a SQLJ connection context and a JDBC
connection, bear in mind that the two objects are sharing the same
underlying physical connection.
Converting from Connection Contexts to JDBC Connections

If you want to perform a JDBC operation through a database connection that you have
established in SQLJ (for example, if your application calls a library routine that returns
a JDBC connection object), then you must convert the SQLJ connection context
instance to a JDBC connection instance.
Any connection context instance in a SQLJ application, whether an instance of the
sqlj.runtime.ref.DefaultContext class or of a declared connection context class,
contains an underlying JDBC connection instance and a getConnection() method that
returns that JDBC connection instance. Use the JDBC connection instance to create
JDBC statement objects if you want to use JDBC operations.
Following is an example of how to use the getConnection() method.
import java.sql.*;
...
DefaultContext ctx = new DefaultContext
...
(SQLJ operations through SQLJ ctx connection context instance)
...
Connection conn = ctx.getConnection();
...
(JDBC operations through JDBC conn connection instance)
...
The connection context instance can be an instance of the DefaultContext class or of

any connection context class that you have declared.
To retrieve the underlying JDBC connection of your default SQLJ connection, you
can use getConnection() directly from a DefaultContext.getDefaultContext()
call, where getDefaultContext() returns a DefaultContext instance that you had
previously initialized as your default connection and getConnection() returns its
underlying JDBC connection instance. In this case, because you do not have to
use the DefaultContext instance explicitly, you can also use the Oracle.connect()
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method. This method implicitly creates the instance and makes it the default
connection.
See Also:
"Connection Considerations" and "More About the Oracle Class"
Following is an example:
import java.sql.*;
...
Connection conn = Oracle.connect
("jdbc:oracle:thin:@localhost:5221/myservice",
"HR", "hr").getConnection();
...
(JDBC operations through JDBC conn connection instance)
...
Example: JDBC and SQLJ Connection Interoperability for Dynamic SQL

Following is a sample method that uses the underlying JDBC connection instance
of the default SQLJ connection context instance to perform dynamic SQL operations
in JDBC. The dynamic operations are performed using JDBC java.sql.Connection,
java.sql.PreparedStatement, and java.sql.ResultSet objects. Alternatively, you
can use Oracle SQLJ extensions for dynamic SQL operations.
See Also:
Oracle Database JDBC Developer's Guide and "Support for Dynamic SQL"
import java.sql.*;
public static void projectsDue(boolean dueThisMonth) throws SQLException {
// Get JDBC connection from previously initialized SQLJ DefaultContext.

Connection conn = DefaultContext.getDefaultContext().getConnection();
String query = "SELECT name, start_date + duration " +

"FROM projects WHERE start_date + duration >= sysdate";
if (dueThisMonth)
query += " AND to_char(start_date + duration, 'fmMonth') " +
" = to_char(sysdate, 'fmMonth') ";
PreparedStatement pstmt = conn.prepareStatement(query);

ResultSet rs = pstmt.executeQuery();
while (rs.next()) {
System.out.println("Project: " + rs.getString(1) + " Deadline: " +
rs.getDate(2));
}
rs.close();
pstmt.close();
}
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Converting from JDBC Connections to Connection Contexts

If you initiate a connection as a JDBC Connection instance but later want to use it as
a SQLJ connection context instance (for example, if you want to use it in a context
expression to specify the connection to use for a SQLJ executable statement), you can
convert the JDBC connection instance to a SQLJ connection context instance.
The DefaultContext class and all declared connection context classes have a
constructor that takes a JDBC connection instance as input and constructs a SQLJ
For example, presume you instantiated and defined the JDBC connection instance
conn and want to use the same connection for an instance of a declared SQLJ
connection context class MyContext. You can do this as follows:
...
...
MyContext myctx = new MyContext(conn);
...
About Shared Connections

A SQLJ connection context instance and the associated JDBC connection instance
share the same underlying physical connection. As a result, the following is true:
• When you get a JDBC connection instance from a SQLJ connection context
instance (using the connection context getConnection() method), the Connection
instance inherits the state of the connection context instance. Among other things,
the Connection instance will retain the auto-commit setting of the connection
context instance.
• When you construct a SQLJ connection context instance from a JDBC connection
instance (using the connection context constructor that takes a connection
instance as input), the connection context instance inherits the state of the
Connection instance. Among other things, the connection context instance will
retain the auto-commit setting of the Connection instance. By default, a JDBC
connection instance has an auto-commit setting of true, but you can alter this
through the setAutoCommit() method of the Connection instance.
• Given a SQLJ connection context instance and associated JDBC connection
instance, calls to methods that alter session state in one instance will also affect
the other instance, because it is actually the underlying shared session that is
being altered.
• Because there is just a single underlying physical connection, there is also a single
underlying set of transactions. A COMMIT or ROLLBACK operation in one connection
instance will affect any other connection instances that share the same underlying
connection.
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Note:
It is also possible for multiple SQLJ connection context instances to be
created from the same JDBC connection instance and, therefore, to share
the same underlying physical connection. This might be useful, for example,
if you want to share the same set of transactions between program modules.
The preceding notes apply to this situation as well.
Closing Shared Connections

When you get a JDBC connection instance from a SQLJ connection context instance
(using the getConnection() method) or you create a SQLJ connection context
instance from a JDBC connection instance (using the connection context constructor),
you must close only the connection context instance. By default, calling the close()
method of a connection context instance closes the associated JDBC connection
instance and the underlying physical connection, thereby freeing all resources
associated with the connection.
If you want to close a SQLJ connection context instance without closing the associated
JDBC connection instance (if, for example, the Connection instance is being used
elsewhere, either directly or by another connection context instance), then you can
specify the boolean constant KEEP_CONNECTION to the close() method, as follows
(assume a connection context instance ctx):
ctx.close(ConnectionContext.KEEP_CONNECTION);
If you do not specify KEEP_CONNECTION, then the associated JDBC connection instance
is closed by default. You can also specify this explicitly:
ctx.close(ConnectionContext.CLOSE_CONNECTION);

sqlj.runtime.ConnectionContext interface.
If you close only the JDBC connection instance, this will not close the associated
SQLJ connection context instance. The underlying physical connection would be
closed, but the resources of the connection context instance would not be freed until
garbage collection.
Note:
• If the same underlying JDBC connection is shared by multiple

connection context instances, then use KEEP_CONNECTION when closing
all but the last remaining open connection context instance.
• An error message will be issued if you try to close a connection context
instance whose underlying JDBC connection has already been closed,
or if you try to close the underlying connection when it has already been
closed. If you encounter this, then verify that the JDBC connection is not
being closed independently by JDBC code and all preceding close()
calls on SQLJ connection context instances that use the underlying
connection use the KEEP_CONNECTION parameter.
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8.6.2 SQLJ Iterator and JDBC Result Set Interoperability

SQLJ enables you to convert in either direction between SQLJ iterators and JDBC
result sets. For situations where you are selecting data in a SQLJ statement but do
not care about strongly typed iterator functionality, SQLJ also supports a weakly typed
iterator, which you can convert to a JDBC result set.
Converting from Result Sets to Named or Positional Iterators

There are a number of situations where you might find yourself manipulating JDBC
result sets. For example, another package might be implemented in JDBC and
provide access to data only through result sets or might require ResultSetMetaData
information because it is a routine written generically for any type of result set. Or your
SQLJ application might invoke a stored procedure that returns a JDBC result set.
If the dynamic result set has a known structure, it is typically desirable to manipulate it
as an iterator to use the strongly typed paradigm that iterators offer.
In SQLJ, you can populate a named or positional iterator object by converting an
existing JDBC result set object. This can be thought of as casting a result set to an
iterator, and the syntax reflects this as follows:
#sql iter = { CAST :rs };
This binds the result set object, rs, into the SQLJ executable statement, converts the
result set, and populates the iterator, iter, with the result set data.
Following is an example. Assume myEmpQuery() is a static Java function in a class

called RSClass, with a predefined query that returns a JDBC result set object:
import java.sql.*;
...
#sql public iterator MyIterator (String ename, float sal);
...
ResultSet rs;
MyIterator iter;
...
rs = RSClass.myEmpQuery();
#sql iter = { CAST :rs };
...
(process iterator)
...
iter.close();
...
This example could have used a positional iterator instead of a named iterator. The
functionality is identical.
The following rules apply when converting a JDBC result set to a SQLJ iterator and
processing the data:
• To convert to a positional iterator, the result set and iterator must have the same
number of columns and the types must map correctly.
• To convert to a named iterator, the result set must have at least as many columns
as the iterator and all columns of the iterator must be matched by name and type.
If the result set and iterator do not have the same number of columns, then the
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SQLJ translator will generate a warning unless you use the -warn=nostrict option
setting.
• The result set being cast must implement the java.sql.ResultSet interface.
The class oracle.jdbc.OracleResultSet implements this interface, as does any
standard result set class.
• The iterator receiving the cast must be an instance of an iterator class that was
declared as public.
• Do not access data from the result set, either before or after the conversion.
Access data from the iterator only.
• When you are finished, close the iterator, not the result set. Closing the iterator will
also close the result set, but closing the result set will not close the iterator. When
interoperating with JDBC, always close the SQLJ entity.
Converting from Named or Positional Iterators to Result Sets

You might also encounter situations where you want to define a query using SQLJ but
ultimately need a result set.
Note:
SQLJ offers more natural and concise syntax, but perhaps you want to do
dynamic processing of the results, or perhaps you want to use an existing
Java method that takes a result set as input.
So that you can convert iterators to result sets, every SQLJ iterator class, whether
named or positional, is generated with a getResultSet() method. This method can be
used to return the underlying JDBC result set object of an iterator object.
Following is an example showing use of the getResultSet() method:
import java.sql.*;
#sql public iterator MyIterator (String ename, float sal);
...
MyIterator iter;
...
#sql iter = { SELECT * FROM employees };
ResultSet rs = iter.getResultSet();
...
(process result set)
...
iter.close();
...
The following rules apply when converting a SQLJ iterator to a JDBC result set and
processing the data.
• When writing iterator data to a result set, you should access data only through the
result set. Do not attempt to directly access the iterator, either before or after the
conversion.
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Support for Dynamic SQL
• When you finish, close the original iterator, not the result set. Closing the iterator
will also close the result set, but closing the result set will not close the iterator.
When interoperating with JDBC, always close the SQLJ entity.
Using and Converting Weakly Typed Iterators (ResultSetIterator)

You might have a situation similar to what is discussed in "SQLJ Iterator and
JDBC Result Set Interoperability", but where you do not require the strongly typed
functionality of the iterator. In such a case, you should be able to use SQLJ syntax
for the query and then processing the data dynamically from a result set. For such
circumstances, you can directly use the sqlj.runtime.ResultSetIterator type to
receive query data.
In using SQLJ statements and ResultSetIterator functionality instead of using JDBC
statements and standard result set functionality, you enable yourself to use the more
concise SELECT syntax of SQLJ.
Following is an example of how to use and convert a weakly typed result set iterator:
import java.sql.*;
...
ResultSetIterator rsiter;
...
#sql rsiter = { SELECT * FROM table };
ResultSet rs = rsiter.getResultSet();
...
(process result set)
...
rsiter.close();
...
Note:
The Oracle SQLJ implementation permits navigation through a result set
iterator using the next() method and FETCH CURRENT syntax. Furthermore,
for scrollable result set iterators, additional navigation methods are
supported.
8.7 Support for Dynamic SQL

The Oracle SQLJ implementation includes extensions to support dynamic SQL,
operations that are not predefined and can change in real time. Dynamic SQL
expressions embedded in SQLJ statements are referred to as meta bind expressions.
Note:
Using JDBC code is still an option for dynamic SQL in Oracle Database 12c
Release 1 (12.1) and might be preferable if code portability is a concern, but
SQLJ support for dynamic SQL permits use of SQLJ as a single, simplified
API for data access.
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• Meta Bind Expressions
• SQLJ Dynamic SQL Examples
8.7.1 Meta Bind Expressions

Meta bind expressions are used for dynamic SQL in SQLJ statements, where
otherwise static SQL clauses would appear. A meta bind expression contains a Java
identifier of String type or a string-valued Java expression that is interpreted at
run time. In addition, so that SQLJ can perform online semantics-checking, a meta
bind expression can optionally include static SQL replacement code to be used for
checking during translation.
Meta Bind Expressions: General Usage and Restrictions

You can use a meta bind expression in place of any of the following:
• Table name
• Column name in a SELECT statement (without the column alias, if specified)
• All or part of a WHERE clause condition
• Role, schema, catalog, or package name in a data definition language (DDL) or
DML statement
• SQL literal value or SQL expression
Be aware of the following restrictions on meta bind expressions, enforced to ensure
that the SQLJ translator can properly determine the nature of the SQL operation and
can perform syntactic analysis of the SQLJ statement as a whole:
• A meta bind expression cannot be the first noncomment of the SQL operation
within a SQLJ statement.
• A meta bind expression cannot contain the INTO token of a SQLJ SELECT INTO
statement and cannot expand to become the INTO-list of a SELECT INTO statement.
• A meta bind expression cannot appear in any of the following kinds of SQL/SQLJ
instructions or clauses: CALL, VALUES, PSM SET, COMMIT, ROLLBACK, FETCH INTO, or
CAST.
Meta Bind Expressions: Syntax and Behavior

Following is the general syntax for meta bind expressions:
:{ Java_bind_expression }
or:
:{ Java_bind_expression :: SQL_replacement_code }
Note that spaces are optional. There can be multiple meta bind expressions within the
SQL instructions of a SQLJ statement.
Java Bind Expression

A Java bind expression can be either of the following:
• Java identifier of the String type
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• Java expression that evaluates to a character string

Java bind expressions within meta bind expressions are subject to standard Java
lexing rules and have syntax similar to that of SQLJ host expressions. However,
unlike host expressions, Java bind expressions within meta bind expressions are not
enclosed within parentheses. This is because, if there is SQL replacement code, then
the :: token acts as a separator between the Java bind expression and the SQL code.
If there is no SQL replacement code, then the closing braces (}) acts as a terminator.
In either case, there is no ambiguity.
Note:
There can be no mode specifiers, IN, OUT, or INOUT, within a Java bind
expression or between : and { of the meta bind expression.
SQL Replacement Code

A SQL replacement code clause consists of a sequence of zero or more SQL tokens,
with the following requirements and restrictions:
• It is subject to SQL lexing rules.
• Braces ({ }) must occur in matching pairs (with the exception of those that are part
of a SQL comment, constant, or identifier).
• There can be no SQLJ host expressions or nested meta bind expressions within
the SQL instructions.
Note:
It is permissible for the SQL replacement code to be empty.
Translation-Time Behavior
Whenever there is SQL replacement code (even if only an empty string) in a meta
bind expression, then the meta bind expression is replaced by the SQL code during
translation. The purpose of SQL replacement code is to enable the SQLJ translator to
perform online semantics-checking.
If any meta bind expression within a SQLJ statement has no SQL replacement code
clause, then the SQLJ translator cannot perform online semantics-checking on the
statement. It is only checked syntactically.
Run-Time Behavior
At run time, each meta bind expression is replaced by the evaluation of its Java
bind expression. If a Java bind expression evaluates to null, then the dynamic SQL
statement as a whole becomes undefined.
8.7.2 SQLJ Dynamic SQL Examples

This section provides examples of dynamic SQL usage in SQLJ code.
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Example 1
...
int x = 10;
int y = x + 10;
int z = y + 10;
String table = "new_Emp";
#sql { INSERT INTO :{table :: emp} VALUES (:x, :y, :z) };
...
During translation, the SQL operation becomes:

INSERT INTO emp VALUES (10, 20, 30);
SQLJ can perform online semantics-checking against a schema that has an emp table.
Perhaps new_Emp only exists in the run-time schema and is not created until the
application executes.
During run time, the SQL operation becomes:
INSERT INTO new_Emp VALUES (10, 20, 30);
Example 2
...
String table = "new_Emp";
String query = "ename LIKE 'S%' AND sal>1000";
#sql myIter = { SELECT * FROM :{table :: emp2}
WHERE :{query :: ename='HR'} };
...

SELECT * FROM emp2 WHERE ename='HR';
SQLJ can perform online semantics-checking against a schema that has an emp2
table.
During run time, the SQL operation becomes:
SELECT * FROM new_Emp WHERE ename LIKE 'S%' AND sal>1000;
Example 3
...
double raise = 1.12;
String col = "comm";
String whereQuery = "WHERE "+col+" IS NOT null";
for (int i=0; i<5; i++)
{
#sql { UPDATE :{"emp"+i :: emp}
SET :{col :: sal} = :{col :: sal} * :raise :{whereQuery ::} };
}
...

UPDATE emp SET sal = sal * 1.12;
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SQLJ can perform online semantics-checking against a schema that has an emp table.
There is no WHERE clause during translation, because the SQL replacement code is
empty.
During run time, the SQL operation is executed five times, becoming:
UPDATE emp0 SET comm = comm * 1.12 WHERE comm IS NOT null;
Example 4
...
double raise = 1.12;
String col = "comm";
String whereQuery = "WHERE "+col+" IS NOT null";
for (int i=0; i<10; i++)
{
#sql { UPDATE :{"emp"+i}
SET :{col :: sal} = :{col :: sal} * :raise :{whereQuery ::} };
}
...
The run-time behaviors of Example 3 and Example 4 are identical. However, a

difference occurs during translation, where SQLJ cannot perform online semantics-
checking for Example 4, because there is no SQL replacement code for the first meta
bind expression, :{"emp"+i}.
Example 5: Dynamic SQL with FETCH from Result Set Iterator

This example is a rework of "Example: JDBC and SQLJ Connection Interoperability
for Dynamic SQL", using SQLJ statements instead of JDBC statements. This example
also uses FETCH CURRENT functionality from a result set iterator.
import java.sql.*;
public static void projectsDue(boolean dueThisMonth) throws SQLException {
ResultSetIterator rsi;
String andClause = (dueThisMonth) ?
" AND to_char(start_date + duration, 'fmMonth' ) "
+ " = to_char(sysdate, 'fmMonth') "
: "";
#sql rsi = { SELECT name, start_date + duration FROM projects
WHERE start_date + duration >= sysdate :{andClause :: } };
while (rsi.next())
{
String name = null;
java.sql.Date deadline = null;
#sql { FETCH CURRENT FROM :rsi INTO :name, :deadline };
System.out.println("Project: " + name + "Deadline: " + deadline);
}
rsi.close();
}
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Using Stored Outlines
8.8 Using Stored Outlines
Note:
Starting from Oracle Database 12c Release 2 (12.2), this feature is
deprecated, and replaced with SQL Plan Management (SPM). Oracle
recommends that you take advantage of the new feature, which is more
powerful and offers better performance. For more information about SPM,
refer to "Using Plan Baselines".
If you run the risk of any performance changes in the application due to change
in the environment, then you may use the outline feature of Oracle. An outline is
implemented as a set of optimizer hints that are associated with the SQL statement.
If the use of the outline is enabled for the statement, Oracle automatically considers
the stored hints and tries to generate an execution plan in accordance with those hints.
You can group outlines into categories, that is, whether they are default or as specified
by the client, and control the category of outlines Oracle uses to simplify outline
administration and deployment. The hints in the outlines are used during the execution
of respective statements if you have set USE_STORED_OUTLINES to the category name
or to TRUE.
See Also:
Oracle Database SQL Language Referencefor more information about
outlines.
When you translate the file with the new outline option set to true or the category
name, then:
1. A separate SQL file is created containing the CREATE OUTLINE statements for all
the SQL statements present in the input SQLJ file.
2. A log file containing the SQL statements, outline name, outline SQL statement,
outline category, and status information is generated.
3. If you specify the -runoutline option, then the SQL file generated is run at the
end of successful translation of the input file.
SQL statements that can be used to create outlines are:
• SELECT
• DELETE
• UPDATE
• INSERT ... SELECT
• CREATE TABLE ... AS SELECT
You have the following restrictions on creating outlines:
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• You cannot create outlines on MERGE statements.

• You cannot create outlines on a multi-table INSERT statement.
• The SQL statement in the outline cannot include any DML operation on a remote
object.
Options to Generate Outlines
Note:
The outline options are valid only if online checking is done.
Consider the SQLJ program abc.sqlj contains the following code snippet:
{
#sql iter = {SELECT * FROM employees WHERE employee_id=:var;}
#sql iter1 = {SELECT * FROM departments};
}
Compile the SQLJ program as:

%sqlj -url=jdbc:oracle:oci8:@ -user=HR -outline=abccat abc.sqlj
Password: password
The generated SQL file abc_sqlj.sql for the above SQLJ code snippet looks as
follows:
CREATE OR REPLACE OUTLINE abccat_abc_sqlj_0001 FOR CATEGORY abccat ON SELECT *
FROM employees WHERE employee_id=:B1
/* abccat_abc_sqlj_0001 */;

FROM departments
/* abccat_abc_sqlj_0002 */;
Note:
The filename is not included in the outline name or comment when a prefix
is given. In this section, you will see examples with and without using prefix.
For more information on prefix, refer to "sqlj.outlineprefix".
The option -outline generates two files at the end of successful translation: a SQL file
and a LOG file. The generated SQL file name has the following format:
<filename>_<filetype>.sql
For example, the generated SQL file for filename abc.sqlj is abc_sqlj.sql.
The format of the unique identifier used as outline name and comment is:
<categoryname >_<filename>_<filetype>_<sequence no.>
where, the sequence number is a four-digit sequence number ranging from 0001 to
9999. If the SQLJ program contains more than 9999 SQL statements, then you get the
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"Max sequence number exceeded for outlines" error. For example, the format of the
unique identifier generated for abc.sqlj is abccat_abc_sqlj_0001, where, abccat is
the name of the category.
Note:
The same comment is added to the SQLs in the generated java or class file
that is used at runtime.
If you set outline to true, then the default category will be used to store the outlines:
%sqlj -user=HR -url=jdbc:oracle:oci8:@ -outline=true abc.sqlj
Password: password
In this case, the generated SQL file abc_sqlj.sql looks as follows:

CREATE OR REPLACE OUTLINE default_abc_sqlj_0001 ON SELECT * FROM employees WHERE
employee_id=:B1 /* default_abc_sqlj_0001 */;
CREATE OR REPLACE OUTLINE default_abc_sqlj_0002 ON SELECT * FROM departments /*

default_abc_sqlj_0002 */;
You can use the following command to set the outline name to a particular prefix:
%sqlj -user=HR -url=jdbc:oracle:oci8:@ -outline=abccat -outlineprefix=pref1
abc.sqlj
Password: password

CREATE OR REPLACE OUTLINE pref1_0001 FOR CATEGORY abccat ON SELECT * FROM
employees WHERE employee_id=:B1 /* pref1_0001 */';
CREATE OR REPLACE OUTLINE pref1_0002 FOR CATEGORY abccat ON SELECT * FROM

departments /* pref1_0002 */';
Note:
If you set the -outlineprefix option, then you can pass only one SQLJ file
to the translator.
Note:
To translate multiple files with the outlineprefix option, you can do the
following:
%sqlj -outline=abccat -outlineprefix=pref1,pref2,pref3 abc.sqlj
def.sqlj fgh.sqlj
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Currently, the upper limit on the length of the outline name is 30 bytes. Hence, if
the generated outline name exceeds 30 bytes, a SQLJ error "Outline name exceeds
maximum limit. Use -outlineprefix option" is thrown. In such cases, if you want
to use the -outline option, you need to call -outlineprefix option as shown in the
preceding example. If you want database server to generate the outline names instead
of the SQLJ generated outline names, then you can set the -outlineprefix option to
none. For example:
%sqlj -user=HR -url=jdbc:oracle:oci8:@ -outline=abccat -outlineprefix=none
abc.sqlj
Password: password

CREATE OR REPLACE OUTLINE FOR CATEGORY abccat ON SELECT * FROM employees WHERE
employee_id=:B1 /* abccat_abc_sqlj_0001 */';
CREATE OR REPLACE OUTLINE FOR CATEGORY abccat ON SELECT * FROM departments /*

abccat_abc_sqlj_0002 */';
If you want to translate multiple files with the -outlineprefix option, then you can use
the following command:
%sqlj -user=HR -url=jdbc:oracle:oci8:@ -outline=abccat -
outlineprefix=pref1,pref2 abc.sqlj def.sqlj
Password: password
If the SQLJ file is part of a package and you have not specified the -outlineprefix
option, then the package name is appended to the outline name and is added
to the comment. For example, if abc.sqlj is part of xyz.def.fgh package, then
generated SQL file abc_sqlj.sql, for the command %sqlj -url=jdbc:oracle:oci8:@
-user=HR/password -outline=abccat abc.sqlj looks as follows:
CREATE OR REPLACE OUTLINE abccat_xyz$def$fgh$abc_sqlj_0001 FOR CATEGORY abccat
ON SELECT * FROM employees WHERE employee_id=:B1
/* abccat_xyz$def$fgh$abc_sqlj_0001 */;
CREATE OR REPLACE OUTLINE abccat_xyz$def$fgh$abc_sqlj_0002 FOR CATEGORY abccat

ON SELECT * FROM departments
/* abccat_xyz$def$fgh$abc_sqlj_0002 */;
If you want the generated SQL file to be executed by the translator at the end of
successful translation, then you can set the runoutline option to true. By default it is
false. For example:
%sqlj -user=HR -url=jdbc:oracle:oci8:@ -outline=default -runoutline=true abc.sqlj
Password: password
Now, if you want to retrieve the outline name for exporting or for modifying the plan
of the SQL code, then you can retrieve the same from the OL$ table, either manually
or by using a tool. You can use the comment in the SQL query to search for the
appropriate SQL statement to identify the outline name because the comment uniquely
identifies the SQL statement.
Table 8-1 shows all the options and values you can pass to the translator for
generating outlines.
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Table 8-1 Table showing the options and values for generating outlines
Option Name Option Value

-outline true<category name>
-outlineprefix none<prefix name>|none<prefix name 1,
prefix name 2,…>
-runoutline true|false
See Also:
Oracle Database Reference for more information about outlines.
Generated LOG File Name

The format of the generated file name is:
<filename>_<filetype>.log
For example, on translating abc.sqlj, the generated log file is abc_sqlj.log.
Generated LOG File Format

Suppose, you have the following code snippet:
#sql iter = {SELECT * FROM employees WHERE employee_id=:var };
#sql iter1 = {SELECT * FROM departments };
The generated log file for the preceding code snippet is as follows:
CATERGORY abccat
Source SQL_1
SELECT * FROM employees WHERE employee_id=:B1
OUTLINE NAME
abccat_abc_sqlj_0001
OUTLINE SQL_1
FROM employees WHERE employee_id = :B1
/* abccat_abc_sqlj_0001 */
STATUS success
Source SQL_2
SELECT * FROM departments
OUTLINE NAME
abccat_abc_sqlj_0002
OUTLINE SQL_2
CREATE OR REPLACE OUTLINE abccat_abc_sqlj_2 FOR abccat ON SELECT * FROM
departments
/* abccat_abc_sqlj_2 */
STATUS fail
In the preceding example of the generated log file format:

• Category means the category of the outline to be generated
• Source means the SQL statements for which outline is to be generated
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• Outline Name is the name of the outline to be generated

• Status is the execution status of the SQL statements used as the source. If the
execution is successful, then status is success. Otherwise, it is fail.
Configuration Files
You can set the different command-line options in the configuration file as follows:
sqlj.outline
• Parameter Name: outline
• Parameter Type: String
• Allowable Values: {true|category_name}
• Default Value: true
• Description: Indicates that outline SQL file needs to be generated for the SQL
statements and it should be in:
– DEFAULT category if the value is default, that is, true
– The category name if category_name is mentioned
Outline SQL file is not generated if this option is not used.
• Dependency on other parameters: Online check should be full when this option is
turned on
sqlj.runoutline
• Parameter Name: runoutline
• Parameter Type: boolean
• Allowable Values: {true|false}
• Default Value: false
• Description: If runoutline=true then the generated SQL file should be executed
by the translator at the end of successful translation.
turned on, and the outline option should be set.
sqlj.outlineprefix
• Parameter Name: outlineprefix
• Parameter Type: String
• Allowable Values: {prefix name}, none
• Description: If this option is set, the outline name in the generated SQL is set
to <prefix>_<seqno>. When this option is set to any value apart from none in
the properties file, only one SQLJ file may be passed to the translator. If the
option is set to none, outline name is generated by the system when the create
outline statement is executed in the server. Also, you may pass multiple files to
the translator when –outlineprefix is set to none.
turned on, and the outline option should be set.
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Using Plan Baselines
8.9 Using Plan Baselines

Starting from Oracle Database 12c Release 2 (12.2), SQLJ supports the creation
of plan baselines using Oracle Database SQL Plan Management (SPM). You can
generate plan baselines at the time of translating the SQLJ files. The necessary SQL
statements to create the plan baselines are generated in the .sql files. You can
review, tune, and fix the plan baselines before deploying the SQLJ application.
See Also:
Oracle Database SQL Tuning Guide for more information about plan
baselines
This section contains the following topics:

• Generating Plan Baselines
• Command-Line and Property File Options
8.9.1 Generating Plan Baselines

You can generate plan baselines for all the SQL statements that are supported by
SPM. The generated log file reports the unsupported statements, if any.
Parameters
When specifying plan baseline options, SQLJ generates SQL files with calls to the
dbms_spm_internal.create_sql_plan_baseline procedure. This procedure has the
following parameters:
Parameter Description
SQL_TEXT Specifies the SQL text for which the plan baseline needs to be
created.
PARSING_SCHEMA Specifies the schema that is used for semantic checking of the
SQL text passed.
PLAN_NAME Specifies the name of the plan baseline. This parameter is
optional. If this parameter is not specified, then the default plan
name is default.
ENABLED Specifies whether the plan is to be enabled or not. Default value is
yes.
FIXED Specifies whether the plan will be a fixed plan or not. Default value
is no.
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Note:
• To generate and execute the plan baseline SQL statements, you must
have the Execute privilege on the DBMS_SPM_INTERNAL package and the
Administer SQL Management Object privilege.
• The plan baseline options are valid only if online semantic checking
is done. If you specify these options with offline semantic checking,
then the options are ignored and a warning is thrown informing that the
options should be used with online semantic checking only.
8.9.2 Command-Line and Property File Options

Use the following command-line options for generating plan baseline SQL statements:
• plan_baseline
• plan_prefix
• plan_run
• plan_fixed
• plan_enabled
Note:
The generated files specify the appropriate user to run the files. For example,
the following statements in a generated file specify that HR can run the file:
var ORA_SPM_PARSE_SCHEMA varchar2(30);
exec :ORA_SPM_PARSE_SCHEMA:='HR';
8.9.2.1 plan_baseline
Use the plan_baseline option to specify whether baseline plans should be generated
for all the SQL statements in the SQL file or not. If you set this option to true, then
default is used as the baseline name. The baseline name is the equivalent to the
category name when you use outlines. The value you provide for this option is used as
the module name when running the SQL file.
The name of the SQL file is translated with a sequence number and the combination is
used to uniquely identify each SQL statement in the SQL file. This combination is also
used as the name of the plan. The sequence number can vary from 0 to 9999. The
format of the plan name is as follows:
<filename>_<filetype>_<sequence_no>
Syntax
In command-line, the plan_baseline option is specified as the following:
-plan_baseline= <true/false/module_name>
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In the property file, the plan_baseline option is specified as the following:

sqlj.plan_baseline=<true/false/module_name>
Default Value
The default value for the plan_baseline option is false, in which case the plan
baselines are not generated. If you specify the value true for this option, the module
name is default.
Example
sqlj test.sqlj –plan_baseline=true -user=HR/hr
If the test.sqlj is a part of a package named mypackage and contains only the
following two SQL statements:
Select first_name from employees;
Select employee_id from employees;
Then, the content of the generated SQL file is:

begin
dbms_application_info.set_module(‘default','');
end;
BEGIN
BEGIN
d := SYS.DBMS_SPM.DROP_SQL_PLAN_BASELINE( PLAN_NAME =>
'mypackage_test_sqlj_0000') ;
EXCEPTION
WHEN OTHERS THEN NULL;
END;
c:=SYS.DBMS_SPM_INTERNAL.CREATE_SQL_PLAN_BASELINE(
'Select first_name from employees /*mypackage_test_sqlj_0000*/',
:ORA_SPM_PARSE_SCHEMA,
'mypackage_test_sqlj_0000',
'no',
'no');
END ;
/
BEGIN
BEGIN
EXCEPTION
END;
'Select employee_id from employees /*mypackage_test_sqlj_0001*/',
'no',
'no');
END ;
/
If the test.sqlj contains only the following two SQL statements:
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And you provide an SPM plan name as the following:

sqlj –plan_name=mybaseline -user=HR/hr test.sqlj

var ORA_SPM_PARSE_SCHEMA varchar2(30) ;
begin
dbms_application_info.set_module(‘mybaseline,'');
end;
BEGIN
BEGIN
EXCEPTION
END;
'Select first_name from employees /*mypackage_test_sqlj_0000*/',
'no',
'no');
END ;
/
BEGIN
BEGIN
EXCEPTION
END;
'Select employee_id from employees /*mypackage_test_sqlj_0001*/',
'no',
'no');
END ;
/
8.9.2.2 plan_prefix
Use the plan_prefix option to specify a name for the plan. This corresponds to the
PLAN_NAME argument of the create_sql_plan_baseline procedure. If you do not use
this option, then a plan name is generated automatically.
Syntax
In command-line, the plan_prefix option is specified as the following:
-plan_prefix=<name>
In the property file, the plan_prefix option is specified as the following:

sqlj.plan_prefix=<name>
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Default Value
The value for the plan_prefix option is none. If you specify any other value for this
option, then the format of the plan name becomes the following:
<name>_<sequence_no>
Example
sqlj test.sqlj –plan_baseline=mybaseline true -user=HR/hr –
plan_prefix=myprefix
Suppose, test.sqlj contains only the following two SQL statements:


begin
end;
BEGIN
BEGIN
d := SYS.DBMS_SPM.DROP_SQL_PLAN_BASELINE( PLAN_NAME => 'myprefix_0000') ;
EXCEPTION
END;
'Select first_name from employees /*myprefix_0000*/',
'myprefix_0000',
'no',
'no');
END ;
/
BEGIN
BEGIN
EXCEPTION
END;
'Select employee_id from employees /*myprefix_0001*/',
'myprefix_0001',
'no',
'no');
END ;
8.9.2.3 plan_run
Use the plan_run option to specify if you want SQLJ to execute the generated SQL file
at the end of translation.
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Note:
You must have the following privileges to execute the generated SQL file:
• Execute privilege on the DBMS_SPM_INTERNAL package
• Administer SQL Management Object privilege
Syntax
In command-line, the plan_run option is specified as the following:
-plan_run=<yes|no>
In the property file, the plan_run option is specified as the following:

sqlj.plan_run=<yes|no>
Default Value
This default value for the plan_run option is yes.
8.9.2.4 plan_fixed
Use the plan_fixed option to specify whether the generated baseline should be fixed
or not.
Syntax
In command-line, the plan_fixed option is specified as the following:
-plan_fixed = <yes|no>
In the property file, the plan_fixed option is specified as the following:

sqlj.plan_fixed=<yes|no>
Default Value
This default value for this option is yes.
8.9.2.5 plan_enabled
Use the plan_enabled option to specify whether the generated baseline should be
enabled or not.
Syntax
In command-line, the plan_enabled option is specified as the following:
-plan_enabled = <yes|no>
In the property file, the plan_enabled option is specified as the following:

sqlj.plan_enabled=<yes|no>
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Default Value
This default value for this option is yes.
8.9.3 Generated SQL File

At the end of precompilation of the SQLJ file with options described in Command-Line
and Property File Options, a SQL file is generated. This SQL file contains the SQL
statements for creating SPM plans for each SQL statement in the SQLJ file.
This section contains the following topics:
• Generated SQL File Name
• Generated SQL File Format
8.9.3.1 Generated SQL File Name

The name of the generated SQL file is in the following format:
<filename>_<filetype>_bln.sql
For SQLJ, the file type is always .sqlj. So, the name of the SQL file is always in the
following format:
<filename>_sqlj_bln.sql
8.9.3.2 Generated SQL File Format

Suppose, the test.sqlj file is a part of the package mypackage and it contains the
following SQL statements:
#sql {select * from employees };
#sql {select manager_id from employees };
If you precompile the file with the following command:

sqlj test.sqlj –plan_baseline=mybaseline –plan_prefix=myprefix -userid=HR/hr
Then the content of the generated SQL file mypackage_test_sqlj_bln.sql is:

var ORA_SPM_PARSE_SCHEMA varchar2(30) ;
begin
end;
BEGIN
BEGIN
EXCEPTION
END;
'Select first_name from employees /*myprefix_0000*/',
'myprefix_0000',
'no',
'no');
END ;
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/
BEGIN
BEGIN
EXCEPTION
END;
'Select employee_id from employees /*myprefix_0001*/',
'myprefix_0001',
'no',
'no');
END ;
Note:
• The sequence number 0000 and 0001 are used to uniquely identify the
plan name for each SQL statement.
• If you specify a value other than none with the plan_prefix option, then
the prefix value is used instead of the value that is specified with the
–plan_baseline option.
8.9.4 Generated Log File

At the end of precompilation a SQL file is generated. This section describes the
following details of the log file:
• Generated Log File Name
• Generated Log File Format
8.9.4.1 Generated Log File Name

The name of the generated log file is in the following format:
<filename>_<filetype>_bln.log
For SQLJ, the file type is always .sqlj. So, the name of the SQL file is always in the
following format:
<filename>_sqlj_bln.log
8.9.4.2 Generated Log File Format

#sql {select manager_id from employees };

sqlj test.sqlj –plan_baseline=true userid=HR/hr
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Then the content of the generated log file is:

MODULE default
SOURCE SQL_0
select * from employees;
PLAN NAME
mypackage_test_sqlj_0000
STATUS Success
/******************************************/
/******************************************/
MODULE default
SOURCE SQL_1
select manager_id from employees
PLAN NAME
mypackage_test_sqlj_0001
STATUS Success
/******************************************/

sqlj test.sqlj –plan_baseline=true userid=HR/hr –plan_prefix=myprefix
Then the content of the generated log file is:

MODULE default
SOURCE SQL_0
select * from employees;
PLAN NAME
myprefix_0000
STATUS Success
/******************************************/
/******************************************/
MODULE default
SOURCE SQL_1
select manager_id from employees
PLAN NAME
myprefix_0001
STATUS Success
/******************************************/
8.9.5 Generated Java File

At the end of precompilation a Java file is generated.

sqlj test.sqlj –plan_baseline=mybaseline –plan_prefix=myprefix -userid=HR/hr
Then the generated Java file has an identifier appended to the SQL statement as
follows:
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try {
String theSqlTS = "select first_name from employees /
*mybaseline_test_sqlj_0001*/";
__sJT_st = __sJT_ec.prepareOracleStatement(__sJT_cc,"0Select",theSqlTS);
// execute query
iter = new Iter(new
sqlj.runtime.ref.OraRTResultSet(__sJT_ec.oracleExecuteQuery(),__sJT_st,"0Select",
null));
} finally { __sJT_ec.oracleCloseQuery(); }
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9
Translator Command Line and Options
Once you have written your source code, you must translate it using the SQLJ
translator. This chapter covers the SQLJ translator command line options and
properties files. The following topics are covered:
• Translator Command Line and Properties Files
• Basic Translator Options
• Advanced Translator Options
• Translator Support and Options for Alternative Environments
9.1 Translator Command Line and Properties Files

The sqlj script invokes a Java virtual machine (JVM) and passes the class name
of the SQLJ translator, sqlj.tools.Sqlj, to the JVM. The JVM invokes the translator
and performs operations such as parsing the command line and properties files. For
simplicity, running the script is referred to as running SQLJ, and its command line is
referred to as the SQLJ command line.
The typical general syntax for the command line is as follows:
% sqlj <optionlist> filelist
The optionlist is a list of SQLJ option settings separated by spaces. There are also
prefixes to mark options to pass to the Java interpreter, compiler, and customizer.
The filelist is the list of files, delimited by spaces, to be processed by the SQLJ
translator. The files can be .sqlj, .java, .ser, or .jar files. The * wildcard entry can
be used in file names. For example, Foo*.sqlj would find Foo1.sqlj, Foo2.sqlj, and
Foobar.sqlj.
Note:
• All options need not precede the file list. Options may appear anywhere
in the command line and are processed in order.
• All command-line options apply to all files being translated. It is not
possible to have file-specific option settings.
Do not include .class files in the file list, but ensure that your classpath is set so that
the SQLJ translator can find any classes it must have for type resolution of variables
in your SQLJ source files. If the -checksource flag is enabled, which is the default
setting, then the SQLJ translator can also find classes it needs in uncompiled .java
files in the classpath.
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Translator Command Line and Properties Files
Note:
If you run the script by entering only sqlj, you will receive a synopsis of the
most frequently used SQLJ options. In fact, this is true whenever you run the
script without specifying any files to process. This is equivalent to using the
-help flag setting.

• SQLJ Options_ Flags_ and Prefixes
• Command-Line Syntax and Operations
• Properties Files for Option Settings
• SQLJ_OPTIONS Environment Variable for Option Settings
• Order of Precedence of Option Settings
9.1.1 SQLJ Options, Flags, and Prefixes

This section discusses options supported by the SQLJ translator. Boolean options
are referred to as flags. Prefixes used to pass options to the JVM, which the SQLJ
script invokes, and to the Java compiler and SQLJ profile customizer, which the JVM
invokes, are also listed.
Summary of SQLJ Options

Table 9-1 lists options supported by the SQLJ translator, categorized as follows:
• Flags and options listed as Basic are discussed in "Basic Translator Options".
• Flags, options, and prefixes listed as Advanced are discussed in "Advanced
Translator Options".
• Flags and options listed as Environment are discussed in "Translator Support and
Options for Alternative Environments". These flags and options are for use of a
nonstandard JVM, compiler, or customizer.
• Options with a category of javac are javac compiler options that SQLJ recognizes
directly, without the compiler prefix. They are passed to the Java compiler, typically
javac, and some also affect SQLJ translator settings. These options are discussed
in "Option Support for javac".
Table 9-1 SQLJ Translator Options
Option Description Default Category

-bind-by-identifier Flag to treat multiple appearances of false Advanced
the same host variable in a given SQLJ
statement as a single bind occurrence.
-C Prefix that marks options to pass to the NA Advanced
Java compiler.
-cache Enables caching of online semantics- false Advanced
checking results (to reduce trips to
database).
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Table 9-1 (Cont.) SQLJ Translator Options

-checkfilename Specifies whether a warning is issued true Environment
during translation if a source file name
does not correspond to the name of the
public class (if any) defined there.
-checksource Instructs SQLJ type resolution to examine true Advanced
source files in addition to class files in
certain circumstances.
-classpath Specifies the classpath to the JVM and None Basic
Java compiler; also passed to javac. Use
this on the command line only.
-codegen Specifies mode of code generation: oracle Basic
oracle for Oracle-specific code
generation with direct Oracle Java
Database Connectivity (JDBC) calls; iso
for ISO standard SQLJ code generation.
-compile Enables or disables the Java compilation true Advanced
step, either for .java files generated
during the current SQLJ run or for
previously generated or other .java files
specified on the command line.
-compiler-executable Specifies the Java compiler to use. javac Environment
-compiler-encoding- Instructs SQLJ whether to pass the - true Environment
flag encoding setting, if set, to the Java
compiler.
-compiler-output-file Specifies a file to which the Java compiler None Environment
output should be written. If this option is
not set, then SQLJ assumes that compiler
output goes to standard output.
-compiler-pipe-output- Instructs SQLJ whether to set the true Environment
flag javac.pipe.output system property,
which determines whether the Java
compiler prints errors and messages to
STDOUT instead of STDERR.
-components Specifies the components (packages all Basic
and classes) to instrument for use
with Oracle Dynamic Monitoring Service
(DMS). This assumes instrumentation is
enabled through the -instrument option.
Use all to instrument all components
being translated.
-d Specifies the output directory for .ser Empty Basic
profile files, if applicable, generated by (Use directory of .java
SQLJ, and .class files generated by the files to place
compiler; also passed to javac. generated .class
files; use directory
of .sqlj files to place
generated .ser files.)
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-default-customizer Determines the profile customizer to use. oracle.sqlj. Environment
Specify a class name. runtime.util.
OraCustomizer
-default-url-prefix Sets the default prefix for URL settings. jdbc:oracle:thin: Basic
-depend Passed to javac; enables -checksource. NA javac
This option requires the -C compiler prefix
if set in a properties file.
-deprecation Passed to javac only. This option requires NA javac
the -C compiler prefix if set in a properties
file.
-dir Sets the output directory for SQLJ- Empty Basic
generated .java files. (Use directory of .sqlj
input file.)
-driver Determines the JDBC driver class to oracle.jdbc.OracleDriver Basic
register. Specify a class name or comma-
delimited list of class names.
-encoding Specifies the encoding that SQLJ and the JVM file.encoding Basic
compiler will use in globalization support; setting
also passed to javac. You can use -e on
the command line.
-explain Flag to request cause and action false Basic
information to be displayed with translator
error messages.
-fixedchar Flag to account for blank padding when false Basic
binding a string into a WHERE clause for
comparison with CHAR data.
-g Passed to javac; enables -linemap. This NA javac
option requires the -C compiler prefix if set
in a properties file.
-help -help-long -help- Flags to display different levels of Disabled Basic
alias information about SQLJ option names,
descriptions, and current values. Use
these on the command line only. You can
use -h instead of -help.
-instrument Specifies whether to instrument translated false Basic
files for use with Oracle DMS.
-jdblinemap Variant of -linemap option for use with the false Basic
Sun Microsystems jdb debugger.
-J Prefix that marks options to pass to the NA Advanced
JVM. Use this on the command line only.
-linemap Enables mapping of line numbers between false Basic
the generated Java class file and the
original SQLJ code.
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-n Instructs the sqlj script to echo the full Disabled Basic
command line as it would be passed
to the SQLJ translator, including settings
in SQLJ_OPTIONS, without having the
translator execute it. This is equivalent to
-vm=echo. Use this on the command line
only.
-ncharconv Performs bind to NCHAR columns for false Basic
String host variables.
-nowarn Passed to javac; sets -warn=none. This NA javac
-O Passed to javac; disables -linemap. This NA javac
-offline Determines the offline checker to use for oracle.sqlj.checker. Advanced
semantics-checking. Specify a list of fully OracleChecker
qualified class names.
-online Determines the online checker to use oracle.sqlj.checker. Advanced
for semantics-checking. Specify a fully OracleChecker
qualified class name. (You must also set
-user to enable online checking.)
-optcols Enables iterator column type and size false Basic
definitions to optimize performance. It is
used directly by the translator for Oracle-
specific code generation, or forwarded
to Oracle customizer along with user,
password, and URL settings for ISO code
generation.
-optparams Enables parameter size definitions to false Basic
optimize JDBC resource allocation (used
with -optparamdefaults). This is used
directly by the translator for Oracle-specific
code generation, or forwarded to Oracle
customizer for ISO code generation.
-optparamdefaults Sets parameter size defaults for particular false Basic
data types (used with -optparams).
This is used directly by the translator
for Oracle-specific code generation, or
forwarded to Oracle customizer for ISO
code generation.
-P Prefix that marks options to pass to the NA Advanced
SQLJ profile customizer.
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-parse Option to enable the offline SQL parser. both Advanced
Possible settings: both, online-only,
offline-only, none, or the name of a
Java class that implements an alternative
parser.
Note: Some settings for this option will
also disable online semantics-checking,
overriding the effect of the -user option.
-passes Instructs the sqlj script to run SQLJ in false Environment
two separate passes, with compilation in
between. Use this on the command line
only.
-password Sets the user password for the database None Basic
connection for online semantics-checking.
You can use -p on the command line.
-profile For ISO code generation, enables or true Advanced
disables the profile customization step for
profile files generated during the current
SQLJ run.
-props Specifies a properties file, an alternative to None Basic
the command line for setting options. (The
sqlj.properties is also still read.) Use
this on the command line only.
-ser2class For ISO code generation, instructs SQLJ false Advanced
to translate generated .ser profiles
to .class files.
-status Requests SQLJ to display status false Basic
messages as it runs. Instead of -status,
you can use -v on the command line.
-url Sets the URL for the database connection jdbc:oracle:oci:@ Basic
for online semantics-checking.
-user Enables online semantics-checking and None (no online Basic
sets the user name (and optionally semantics-checking)
password and URL) for the database
connection. You can use -u on the
command line.
-verbose Passed to javac; enables -status. This NA javac
requires the -C compiler prefix if set in a
properties file.
-version -version-long Flag to display different levels of SQLJ Disabled Basic
and JDBC driver version information. Use
these settings on the command line only.
-vm Specifies the JVM to use for running the java Environment
SQLJ translator. Use this on the command
line only.
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-warn Comma-delimited list of flags to cast precision Basic
enable or disable different SQLJ nulls noportable
warnings. Individual flags are strict noverbose
cast/nocast precision/noprecision,
nulls/nonulls, portable/noportable,
strict/nostrict, and verbose/
noverbose. The global flag is all/none.
Notes Regarding Options, Flags, and Prefixes

Keep the following in mind:
• Flags, options, and prefixes listed as command line only in the Description column
of the preceding table cannot be set in a properties file.
• The names of command-line options, including options passed elsewhere, are
case-sensitive and usually all lowercase. Option values are usually case-sensitive
as well.
• Most SQLJ options can also be set in a properties file.

• The SQLJ_OPTIONS environment variable can be used in addition to, or instead of,
the command line for setting options.
• In this document, boolean flags are usually discussed as being true or false, but
they can also be enabled or disabled by setting them to yes/no, on/off, or 1/0.
See Also:
"Command-Line Syntax and Operations"
Notes Regarding the -password Option

You can choose one of the following ways to provide the password, ensuring that it is
not being intercepted by other users through utilities such as ps:
• Omit the -password argument. In this case, you will be prompted on the command
line to enter the password. Then the password argument will not be visible to the
operating system.
• Place the password setting into a properties file, and instruct the SQLJ translator
to use this properties file. Thus it is possible to script SQLJ translation without
exposing the password to the operating system.
• Use SQLJ under JDeveloper. This does not expose the password to the operating
system.
Options for loadjava Compatibility

For compatibility with the loadjava utility used to load Java and SQLJ applications into
an Oracle Database 12c Release 2 (12.2) instance, the following alternative syntax is
recognized for the indicated options when specified on the command line:
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• -e (for -encoding)
• -h (for -help)
• -p (for -password)
• -u (for -user)
• -v (for verbose message output; equivalent to -status)
To maintain full consistency with loadjava syntax, you can use a space instead of
equal sign (=) in setting these options, as in the following example:
-u HR -v -e SJIS
Note:
This alternative option syntax is recognized only on the command line or in
the SQLJ_OPTIONS environment variable, not in properties files.
See Also:
Oracle Database Java Developer’s Guide
Option Support for javac

SQLJ supports option settings for javac, the Java compiler supplied with the Sun
Microsystems Java Development Kit (JDK), in the following ways:
• Some javac options that take values are combined into SQLJ options (-
classpath, -d, -encoding).
• For other javac options that take values, special processing has been
implemented to correctly pass the value to the compiler (-bootclasspath, -
extdirs, -target). These require a compiler prefix. They have no effect on SQLJ
operation.
• Flags for javac are recognized on the command line without a compiler prefix
(-depend, -deprecation, -g, -nowarn, -O, -verbose). Some of these flags affect
SQLJ translator flag settings as well.
This is summarized in Table 9-2. All of these options can be set on the SQLJ
command line or in a properties file, though sometimes a compiler prefix is required,
as noted in the table.
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Note:
• By default, javac compiles classes against the bootstrap and extension

classes of the platform with which it was shipped. But javac also
supports cross-compiling classes against bootstrap and extension
classes of a different Java platform. The javac -bootclasspath and
-extdirs options are for use in cross-compiling (JDK 6).
• By default, javac generates .class files that are compatible with the
JDK version from which javac was obtained. Use the -target option to
alter this.
Table 9-2 SQLJ Support for javac Options
Command-Line Description Relationship to SQLJ

Option (with -C
Prefix if Noted)
-C-bootclasspath Instructs javac to cross-compile against None
the specified set of bootstrap classes.
-classpath Sets the classpath for javac and the This is also a SQLJ option.
JVM.
-d Sets the output directory for .class files This is also a SQLJ option
and SQLJ profile files.
-depend Instructs javac to compile out-of-date Enables the SQLJ -
files recursively. checksource option.
-deprecation Instructs javac to output source locations None
where deprecated APIs are used.
-encoding Sets the encoding for both SQLJ and This is also a SQLJ option.
javac.
-C-extdirs Instructs javac to cross-compile against None
the specified extension directories.
-g Generates javac debugging information. Enables the SQLJ -
linemap option.
-nowarn Instructs javac to generate no warnings. Sets the SQLJ option -
warn=none.
-O Instructs javac to optimize. Disables the SQLJ -
linemap option.
-C-target Instructs javac to generate .class files None
to work only on JVMs of the specified JDK
version level or higher.
-verbose Instructs javac to produce real-time Enables the SQLJ -
status messages. status option.
Refer to javac documentation for additional information about javac option settings
and functionality.
Syntax Notes for javac Options

Keep the following in mind regarding the javac options syntax:
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• If you want to set different classpath values for the Java compiler and for the JVM
that runs SQLJ, then you must use separate settings, one with a -C prefix and one
with a -J prefix. Otherwise, no prefix is required.
• Do not use the -C prefix to specify the -d or -encoding compiler options. Note
that this also means that SQLJ and the compiler use the same settings for -d and
-encoding.
• You can optionally use the -C prefix for -depend, -deprecation, -g, -nowarn, -O,
and -verbose.
• All javac options, aside from those that are also SQLJ options (-classpath, -d,
and -encoding) require the compile. prefix if you set them in a properties file.
• For consistency, it is advisable to use an equal sign (=) for options that take
values, but a space also works when using a compiler prefix (-C on the command
line or compile. in a properties file).
Example
The following example, which is a single wraparound command line, uses the -C-
bootclasspath, -C-extdirs, and -C-target options.
% sqlj -vm=/usr/local/packages/jdk6/bin/java
-compiler-executable=/usr/local/packages/jdk6/bin/javac
-C-bootclasspath=/usr/local/packages/jdk6/jre/lib/rt.jar
-C-extdirs="" -C-target=1.1.8 Demo.sqlj
Profile Customizer Options

Profile customizer options, that is, options for the customizer harness front end, the
default Oracle customizer, and special customizers for debugging and deployment-
time semantics-checking, are documented in " Customization and Specialized
Customizers". This is relevant for ISO standard code generation only (-codegen=iso).
9.1.2 Command-Line Syntax and Operations

The general sequence of events triggered by running the script sqlj was discussed
in "SQLJ Translation Steps". This section will add some operational details to that
discussion, as part of this overview of the command line.
Use of Command-Line Arguments

Recall the typical general syntax for the command line:
% sqlj <optionlist> filelist
When the sqlj script invokes a JVM, it passes all of its command-line arguments to
the JVM, which later passes them elsewhere, such as to the Java compiler or profile
customizer, as appropriate.
Use an equal sign (=) to specify option and flag settings, although for simplicity you
do not have to specify =true to turn on a flag. Typing the flag name alone will suffice.
However, you must specify =false to turn a flag off. A flag will not toggle from its
previous value. For example:
-linemap=true or just -linemap to enable line-mapping
-linemap=false to disable line-mapping
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Note:
If the same option appears more than once on the command line or in the
properties file, then the last value is used.
Arguments from the Option List

Option list arguments are used in the following ways:
• Options not designated by the -J, -C, or -P prefixes are SQLJ options (except for
directly supported compiler options) and are passed to the SQLJ translator as the
JVM invokes it.
• Options designated by the -J prefix are JVM options and are used by the
JVM directly. Such options must be specified on the command line or in the
SQLJ_OPTIONS environment variable. As with translator options, use an equal sign
(=) in setting the option, such as:
-J-Djavac.pipe.output=true
If you want to set different classpath values for the Java compiler and for the JVM
that runs SQLJ, you must use separate settings, one with a -C prefix and one with
a -J prefix.
• Options designated by the -C prefix are Java compiler options and are passed to
the compiler as the JVM invokes it. Compiler options taking values require special
support, which has been implemented for javac options. You can use an equal
sign for these, as follows (though a space also works):
-C-bootclasspath=/usr/local/packages/jdk6/jre/lib/rt.jar
• Options designated by the -P prefix are SQLJ profile customizer options and are
passed to the customizer as the JVM invokes it (relevant only for ISO standard
code generation, -codegen=iso). As with translator options, use an equal sign (=)
in setting the option, such as:
-P-user=HR
Any profile customization other than what SQLJ performs automatically is

considered an advanced feature.
See Also:
Customization and Specialized Customizers
Arguments from the File List

The SQLJ front end parses the file list, processes wildcard characters, and expands
file names. By default, files are processed as follows:
• The .sqlj files are processed by the SQLJ translator, Java compiler, and SQLJ
profile customizer (profile customizer for -codegen=iso only).
• The .java files are processed by the Java compiler and are also used by the
SQLJ translator for type resolution.
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• The .ser profiles and .jar files are processed only by the profile customizer
(relevant only for -codegen=iso).
Note that you can specify .sqlj files together with .java files on the command
line, or you can specify .ser files together with .jar files, but you cannot mix the
two categories. If you have .sqlj files and .java files with interdependencies, each
requiring access to code in the others, then enter them all on the command line for a
single execution of SQLJ. You cannot specify them for separate executions of SQLJ,
because then SQLJ would be unable to resolve all the types.
Note:
As an alternative to entering .java file names on the command line, you can
enable the -checksource option and then ensure that the .java files are in
the classpath.
Processing to Avoid Source Conflicts

The SQLJ translator takes steps to try to prevent having multiple source files define
the same class in the same location. If your command-line file list includes multiple
references to the same .sqlj or .java file, then all but the first reference are
discarded from the command line. In addition, if you list a .java and .sqlj file with
the same base name and in the same location without using the -dir option, then only
the .sqlj file is processed. This processing also applies to wildcard characters.
Consider the following command-line examples, where % is the system prompt.

Assume that your current directory is /myhome/mypackage, which contains the files
Foo.sqlj and Foo.java:
% sqlj Foo.sqlj /myhome/mypackage/Foo.sqlj
These both refer to the same file, so the translator discards /myhome/mypackage/
Foo.sqlj from the command line.
% sqlj Foo.sqlj Foo.java
The translator discards Foo.java from the command line. Otherwise, this command
line would result in the translator writing and reading from Foo.java in the same
execution.
% sqlj Foo.*
Again, the translator discards Foo.java from the command line. Otherwise, the
translator would find both Foo.sqlj and Foo.java, which again would cause it to write
and read from Foo.java in the same execution.
% sqlj -dir=outdir -d=outclasses Foo.sqlj Foo.java
This is fine, because the generated Foo.java will be in the outdir subdirectory,
while the Foo.java being read is in the /myhome/mypackage directory. Presuming that
Foo.java and Foo.sqlj define classes in different packages, the .class files created
by Java compilation will be placed in different subdirectories under the outclasses
directory hierarchy.
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This processing of the command line means that you can, for example, type the
following command and have it execute without difficulty (with file references being
automatically discarded as necessary):
% sqlj *.sqlj *.java
This is convenient in many situations.
Command-Line Example and Results

The following is a sample command line, where % is the system prompt. This example
uses some advanced concepts more fully explained later in this chapter, but is
presented in the interest of showing a complete example of command-line syntax.
% sqlj -J-Duser.language=ja -warn=none -J-prof -encoding=SJIS *Bar.sqlj Foo*.java
The sqlj script invokes a JVM, passes it the class name of the SQLJ translator, then
passes it the command-line arguments. The JVM passes the SQLJ options to the
translator and compiler. If there are any options for the JVM, as designated by -J,
then the script passes them to the JVM ahead of the translator class file name (just
as you would type Java options prior to typing the class file name if you were invoking
Java manually). There is no customization in this example, because it uses the default
Oracle-specific code generation.
After these steps are completed, the results are equivalent to the user having
typed the following (presuming SushiBar.sqlj, DiveBar.sqlj, FooBar.java, and
FooBaz.java were all in the current directory):
% java -Duser.language=ja -prof sqlj.tools.Sqlj -warn=none -encoding=SJIS
SushiBar.sqlj DiveBar.sqlj FooBar.java FooBaz.java
Note that this is one wraparound command line.
Echoing the Command Line without Executing

You can use the SQLJ -n option (or, alternatively, -vm=echo) to echo the command line
that the sqlj script would construct and pass to the SQLJ translator, without executing
it. This includes settings in the SQLJ_OPTIONS environment variable as well as on the
command line, but does not include settings in properties files.
9.1.3 Properties Files for Option Settings

You can use properties files, instead of the command line, to set options for the SQLJ
translator, Java compiler, and SQLJ profile customizer.
In addition, if your Java compiler will be running in a separate JVM and you want
to specify options to this JVM regarding operation of the compiler, then you can use
properties files to supply such options. Such options are passed to the JVM at the
time the compiler is run, after the SQLJ translation step. However, it is typical to pass
options to the JVM of the compiler by using the command-line -C-J prefix.
You cannot use properties files to set the following SQLJ options, flags, and prefixes:
• -classpath
• -help, -help-long, -help-alias, -C-help, -P-help
• -J
• -n
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• -passes
• -props
• -version, -version-long
• -vm
It is not possible to use properties files to specify options to the JVM, for example,
because properties files are read after the JVM is invoked.
Also note that in properties files you cannot use option abbreviations recognized on
the command line for compatibility with loadjava (-e, -h, -p, -u, -v).
Properties File Syntax

Option settings in a properties file are placed one per line. Lines with SQLJ options,
compiler options, and customizer options can be interspersed. They are parsed by the
SQLJ front end and processed appropriately.
Syntax for the different kinds of options is as follows:
• Each SQLJ option is prefixed by sqlj. (including the period) instead of an initial
hyphen. Only options that start with this prefix are passed to the SQLJ translator.
For example:
sqlj.warn=none
sqlj.linemap=true
• Each Java compiler option is prefixed by compile. (including the period) instead
of -C-. Options that start with this prefix are passed to the Java compiler. For
example:
compile.verbose
compile.bootclasspath=/usr/local/packages/jdk6/jre/lib/rt.jar
• General profile customization options, which apply regardless of the particular
customizer you are using, are prefixed by profile. (including the period) instead
of -P-. Only options that start with this prefix are passed to the profile customizer.
For example:
profile.backup
profile.user=HR/hr
You can also specify options to a particular customizer by using profile.C as

follows:
profile.Csummary
profile.Coptparamdefaults=VAR%(50),LONG%(500),RAW_TYPE()
Any profile customization other than the default Oracle customization is

considered an advanced feature.
See Also:
Customization and Specialized Customizers
• Comment lines start with a pound sign (#). For example:

# Comment line.
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• Blank lines are also permitted.

As on the command line, a flag can be enabled or disabled in a properties file with
true/false, on/off, 1/0, or yes/no. A flag can also be enabled simply by entering it
without a setting, such as the following:
sqlj.linemap
Note:
For consistency, it is best to always use the equal sign (=) in a properties
file for options that take values, even though there are some circumstances
where a space also works.
Properties File: Simple Example

The following are sample properties file entries:
# Set user and JDBC driver
sqlj.user=HR
# Turn on the compiler verbose option

compile.verbose
These entries are equivalent to having the following on the SQLJ command line:
% sqlj -user=HR -driver=oracle.jdbc.OracleDriver -C-verbose
Properties File: Nondefault Connection Context Classes

Following is a sample properties file that specifies settings for a connection context
class, SourceContext, that you declared:
# JDBC driver
# Oracle 9.2 on spock.natdecsys.com

sqlj.user@SourceContext=sde
sqlj.password@SourceContext=fornow
sqlj.url@SourceContext=jdbc:oracle:thin:@localhost:5221/myservice
# Warning settings
sqlj.warn=all
# Cache
sqlj.cache=on
Default Properties Files

Regardless of whether a properties file is specified on the SQLJ command line, the
SQLJ front end looks for files named sqlj.properties. It looks for them in the Java
home directory, the user home directory, and the current directory, in that order. It
processes each sqlj.properties file it finds, overriding previously set options as it
encounters new ones. Thus, options set in the sqlj.properties file in the current
directory override those set in the sqlj.properties file in the user home directory or
Java home directory.
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See Also:
"Order of Precedence of Option Settings"
9.1.4 SQLJ_OPTIONS Environment Variable for Option Settings

The Oracle SQLJ implementation supports an environment variable called
SQLJ_OPTIONS as an alternative to the command line for setting SQLJ options. Any
option referred to as command line only, meaning it cannot be set in a properties file,
can also be set using the SQLJ_OPTIONS variable.
You can use the SQLJ_OPTIONS variable to set any SQLJ option, but it is intended
especially for option settings to be passed to the JVM. And it is particularly useful
for command-line-only options, such as -classpath, that you use repeatedly with the
same setting.
Following is an example of a SQLJ_OPTIONS setting:
-vm=jview -J-verbose
When you use SQLJ_OPTIONS, SQLJ effectively inserts the SQLJ_OPTIONS settings, in
order, at the beginning of the SQLJ command line, prior to any other command-line
option settings.
Note:
Generally, syntax in SQLJ_OPTIONS is the same as on the command line, but
this may depend on your operating system. There can be operating system
specific restrictions. For example, on Microsoft Windows 95 you use the
Environment tab in the System control panel. Additionally, because Windows
95 does not support the equal sign (=) in variable settings, SQLJ supports
the use of # instead of = in setting SQLJ_OPTIONS. Refer to your operating
system documentation.
9.1.5 Order of Precedence of Option Settings

SQLJ takes option settings in the following order:
1. Sets options to default settings, where applicable.
2. Looks for a sqlj.properties file in the Java home directory. If it finds one, it sets
options as specified there.
3. Looks for a sqlj.properties file in the user home directory. If it finds one, it sets
4. Looks for a sqlj.properties file in the current directory. If it finds one, it sets
5. It looks for option settings in the SQLJ_OPTIONS environment variable and
effectively prepends them to the beginning of the command line. It sets options
as specified in SQLJ_OPTIONS.
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Basic Translator Options
6. It looks for option settings on the command line and sets options as specified
there. As SQLJ processes the command line, it looks in any file specified by the
-props option and sets options as specified there.
Note:
• At each step, SQLJ overrides any previous settings for any given option.
• In the sqlj.properties files, SQLJ reads option settings from top to
bottom, with later entries taking precedence over earlier entries.
• If there is a properties file specified by the -props option on the
command line, SQLJ effectively inserts the option settings of the file into
the position on the command line where the -props option was specified.
• SQLJ reads options on the command line, with options from a -props
file inserted, in order from left to right. Any later (right-hand) setting takes
precedence over earlier (left-hand) settings.
Example
Presume SQLJ is run as follows:
% sqlj -user=HR -props=myprops.properties -dir=/home/java
And presume the file myprops.properties is in the current directory and contains the
following entries:
sqlj.user=tony
sqlj.dir=/home/myjava
These settings are processed as if they were inserted into the command line where
the -props option was specified. Therefore, the tony entry takes precedence over
the HR entry for the user option, but the /home/java entry takes precedence over the /
home/myjava entry for the dir option.
9.2 Basic Translator Options

This section documents the syntax and functionality of the basic flags and options you
can specify in running SQLJ. These options enable you to run in a fairly standard
mode of operation. For options that can also be specified in a properties file, that
syntax is noted as well.
• Basic Options for the Command Line Only
• Options for Output Files and Directories
• Connection Options
• Options for Reporting and Line-Mapping
• Options for DMS
• Options for Code Generation_ Optimizations_ and CHAR Comparisons
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See Also:
• "Properties Files for Option Settings"

• "Advanced Translator Options"
• "Translator Support and Options for Alternative Environments"
9.2.1 Basic Options for the Command Line Only

The following basic options can be specified only on the SQLJ command line or,
equivalently, in the SQLJ_OPTIONS environment variable:
• -props
• -classpath
• -help, -help-long, -help-alias, -P-help, -C-help
• -version, -version-long
• -n
These options cannot be specified in properties files. The command-line-only flags
(-help, -version, and -n) do not support =true syntax. Enable them by typing only the
flag name, as follows:
sqlj -version-long
Note:
Additionally, there are advanced options, flags, and prefixes that can be set
only on the command line or in SQLJ_OPTIONS: -J, -passes, and -vm.
Input Properties File (-props)

The -props option specifies a properties file from which SQLJ can read option
settings. The command-line syntax is as follows:
-props=filename
For example:
-props=myprops.properties
Classpath for Java Virtual Machine and Compiler (-classpath)

For compatibility with the syntax of most JVMs and compilers, SQLJ recognizes the
-classpath option if it is specified on the command line. In setting this option, you
can use either a space, as with most JVMs or compilers, or the equal sign (=),
as with other SQLJ options. The following examples (both for a UNIX environment)
demonstrate this:
-classpath .:$ORACLE_HOME/jdbc/lib/ojdbc6.jar:$ORACLE_HOME/sqlj/lib/
translator.jar:$ORACLE_HOME/sqlj/lib/runtime12.jar
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-classpath= .:$ORACLE_HOME/jdbc/lib/ojdbc6.jar:$ORACLE_HOME/sqlj/lib/
The -classpath option sets the Java classpath for both the JVM and the Java
compiler. If you do not want to use the same classpath for both, then set them
separately using the SQLJ -J and -C prefixes.
See Also:
"Prefixes that Pass Option Settings to Other Executables"
Note:
As with other options described in this chapter, if you use = in setting the
-classpath option, then it is stripped out when the option string is passed
to the JVM and compiler, because JVMs and compilers do not support the =
syntax in their option settings.
The command-line syntax is as follows

sqlj -classpath=class_path
For example:
sqlj -classpath=$ORACLE_HOME/jdbc/lib/ojdbc6.jar:$ORACLE_HOME/sqlj/lib/
SQLJ Option Information (-help)

The following settings of the -help flag, specified on the command line, instruct SQLJ
to display varying levels of information about SQLJ options:
• -help
• -help-long
• -help-alias
You can enable this option by typing the desired setting on the command line as in the
following examples:
% sqlj -help
% sqlj -help-long
% sqlj -help-alias
No input-file translation is performed when you use the -help flag in any of these
forms, even if you include file names and other options on the command line as well.
SQLJ assumes that you either want to run the translator or you want help, but not
both.
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You can also receive information about the profile customizer or Java compiler,
requesting help through the -P and -C prefixes, as in the following examples. As with
the -help flag, no translation is performed if you request customizer or compiler help.
% sqlj -P-help
% sqlj -C-help
As with other command-line-only flags, -help (as well as -P-help and -C-help) does
not support =true syntax. Enable it by typing only the desired flag setting.
Note:
• For compatibility with the loadjava utility, -h is recognized as equivalent

to -help when specified on the command line.
• You can use multiple -help flag settings on the same command line,
including -P-help and -C-help.
• Although -P and -C settings can generally be set in properties files,
-P-help and -C-help are for only the command line.
• Help is also provided if you run SQLJ without specifying any files to
process. This is equivalent to using the -help setting.
The most basic level of help is achieved by specifying the -help setting. This provides
the following:
• A synopsis of the most frequently used SQLJ options
• A listing of the additional -help flag settings available
The -help-long setting provides a complete list of SQLJ option information, including
the following for each option:
• Option name
• Option type (the Java type that the option takes as input, such as int or String)
• Description
• Current value
• How the current value was set (from the command line, from a properties file, or
by default)
Note:
It is often useful to include other option settings on the command line with
a -help-long option, especially with complex options, such as -warn, or
combinations of options, so that you can see what option settings resulted
from your actions.
The -help-alias setting provides a synopsis of the command-line abbreviations

supported for compatibility with the loadjava utility.
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The command-line syntax is as follows:

sqlj help_flag_settings
For example:
sqlj -help
sqlj -help -help-alias
sqlj -help-long
sqlj -warn=none,null -help-long
sqlj -help-alias
By default, these settings are disabled.
SQLJ Version Number (-version)

The following settings of the -version flag, specified on the command line, instruct
SQLJ to display varying levels of information about SQLJ and JDBC driver versions:
• -version
• -version-long
You can enable this option by typing the desired setting on the command line as in the
following examples:
% sqlj -version
% sqlj -version-long
No input-file translation is performed when you use the -version option, even if
you include file names and other options on the command line. SQLJ assumes that
you either want to run the translator or you want version information, but not both.
Properties files and anything else you type on the command line are ignored. As with
other command-line-only flags, -version does not support the =true syntax. Enable it
by typing only the flag name.
The -version setting displays the SQLJ release number, as follows:
sqlj -version
Oracle SQLJ Release 12.1.0.1.0 Production
Copyright © 1997, 2012, Oracle Corporation. All Rights Reserved.
The -version-long setting displays information about the SQLJ and SQLJ run-time
library release, the JDBC driver release number if one can be found, and the Java
environment. For example, if an Oracle JDBC driver is used, this option would display
something as follows:
sqlj -version-long
Oracle SQLJ Release 12.1.0.1.0 Production
Copyright © 1997, 2012, Oracle Corporation. All Rights Reserved.
JDBC version: Oracle JDBC driver version 12.1 (12.1.0.1.0)
Java version: 1.6 (1.6.0_04)
This flag offers a good way to check your SQLJ installation and the JDBC and JDK
versions you are using. The command-line syntax is as follows:
sqlj version_flag_settings
For example:
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sqlj -version
sqlj -version -version-long
sqlj -version-long
By default, these settings are disabled.
Command Line Echo without Execution (-n)

The -n flag, specified on the command line, instructs the sqlj script to construct
the full command line that would be passed to the SQLJ translator, including any
SQLJ_OPTIONS settings, and echo it to the user without having the SQLJ translator
execute it. This includes capturing and echoing the name of the JVM that would
be launched to execute the SQLJ translator and echoing the full class name of the
translator. This does not include settings from properties files.
This is useful in displaying the following:
• The fully expanded form of any options you abbreviated, such as -u and other
abbreviations supported for loadjava compatibility.
• The order in which options would be placed when the overall command string is
constructed and passed to the translator.
• Possible conflicts between SQLJ_OPTIONS settings and command-line settings.
The -n option can appear anywhere on the command line or in the SQLJ_OPTIONS
variable. As with other command-line-only flags, -n does not support the =true syntax.
Enable it by typing only the flag name.
Consider a sample scenario. You have the following setting for SQLJ_OPTIONS:
-user=HR/hr@jdbc:oracle:thin:@ -classpath=/myclasses/bin
You enter the following command line:

% sqlj -n -e SJIS myapp.sqlj
You would see the following echo:

java -classpath /myclasses/bin sqlj.tools.Sqlj -user=HR/hr@jdbc:oracle:thin:@ -C-
classpath=/myclasses/bin
-encoding=SJIS myapp.sqlj
Note that this is all one wraparound line.
Note:
• Echoing your password at the command-line is not a secure practice.

• As an alternative to -n, you can use the -vm=echo setting.
• Another effective way to check option settings is to use the -help-long
flag. This displays current settings for all options, including other options
you set on the command line as well as settings in properties files and in
SQLJ_OPTIONS.
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-n
For example:
-n
By default, this setting is disabled.
9.2.2 Options for Output Files and Directories

The -encoding option specifies encoding for SQLJ input and output source files. The
following options specify where SQLJ output files are placed:
• -d
• -dir
Encoding for Input and Output Source Files (-encoding)

The -encoding option specifies the encoding to be applied to .sqlj and .java input
files and .java generated files for globalization support. For compatibility with javac,
you can use either a space or equal sign (=) in setting this option on the command
line, as in the following examples:
-encoding=SJIS
-encoding SJIS
However, if setting sqlj.encoding in a properties file, then use =, not a space.
When this option is specified, it is also passed to the Java compiler, unless the
-compiler-encoding-flag is off, which uses it to specify encoding for .java files
processed by the compiler.
Note the following:
• As with the -classpath and -d options, if you do use an = in setting the -encoding
option, then it is stripped out when the option string is passed to the JVM and
compiler. This is because JVMs and compilers do not support the = syntax in their
option settings.
• For compatibility with the loadjava utility, -e is recognized as equivalent to -
encoding when specified on the command line.
• The -encoding option does not apply to Java properties files, such as
sqlj.properties and connect.properties. Properties files always use the
encoding 8859_1. This is a feature of Java in general, not SQLJ in particular.
However, you can use Unicode escape sequences in a properties file. You can use
the native2ascii utility to create escape sequences for a natively encoded file.
See Also:
Translator and Run-Time Functionality

-encoding=Java_character_encoding
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For example:
-encoding=SJIS
The syntax for a properties file entry for this option is as follows:
sqlj.encoding=Java_character_encoding
For example
sqlj.encoding=SJIS
By default, this option is set to the JVM system property file.encoding.
Output Directory for Generated .ser and .class Files (-d)

The -d option specifies the root output directory for profiles generated by the SQLJ
translator (relevant for ISO standard code generation, -codegen=iso), and is also
passed to the Java compiler to specify the root output directory for .class files
generated by the compiler. Whether profiles are generated as .ser files (default)
or .class files (if the -ser2class option is enabled) is irrelevant for placement through
the -d option.
Whenever a directory is specified, the output files are generated under this directory
according to the package name, if applicable. For example, if you have source files
in the a.b.c package and specify directory, /mydir, output files will be placed in the /
mydir/a/b/c directory. If you specify a relative directory path, then this will be from
your current directory.
For compatibility with javac, you can use either a space or = in setting this option on
the command line, as in the following examples (both of which make /root the root
directory for generated profile files):
-d=/root
-d /root
However, if setting -d in a properties file, then use =, not a space. For example:
sqlj.d=/root
If your current directory is /root/home/mydir and you set the -d option to the
relative directory path, mysubdir/myothersubdir, as follows, then /root/home/mydir/
mysubdir/myothersubdir will be the root directory for the generated profile files:
-d=mysubdir/myothersubdir
You can also use standard syntax, such as a period for the current directory or two
periods to go up a level, as follows:
-d=.
-d=../paralleldir
If the -d option is empty or not specified, then a generated .class file is placed in the
same directory as the corresponding .java file, which is according to the -dir option
for a .java file generated by SQLJ, and a generated .ser file is placed in the same
directory as the corresponding .sqlj file.
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Note:
• You can specifically set -d to be empty (to override settings in a

properties file, for example) as follows:
-d=
• Throughout this discussion, slash (/) was used as the file separator.
However, it is important to note that in specifying this, or similar options,
you must actually use the file separator of your operating system, as
specified in the file.separator system property of your JVM.
• As with the -classpath and -encoding options, if you do use an equal
sign (=) in setting the -d option, then it is stripped out when the option
string is passed to the JVM and compiler. This is because JVMs and
compilers do not support the = syntax in their option settings.

-d=directory_path
For example:
-d=/topleveldir/mydir
sqlj.d=directory_path
For example:
sqlj.d=/topleveldir/mydir
This option does not have any default value.
Output Directory for Generated .java Files (-dir)

The -dir option specifies the root directory for .java files generated by the SQLJ
translator. Whenever a directory is specified, the output files are generated under
this directory according to the package name, if applicable. For example, if you have
source files in the a.b.c package and specify directory, /mydir, then output files will be
placed in the /mydir/a/b/c directory. If you specify a relative directory path, then it will
be from your current directory.
A simple example is as follows, which will make /root the root directory for
generated .java files:
-dir=/root
Consider that your current directory is /root/home/mydir and you set the -dir option
to the relative directory path mysubdir/myothersubdir as follows:
-dir=mysubdir/myothersubdir
Then /root/home/mydir/mysubdir/myothersubdir will be the root directory for

generated .java files.
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You can also use standard syntax, such as a period for the current directory or two
periods to go up a level, as follows:
-dir=.
-dir=../paralleldir
If the -dir option is not specified, then files are generated under the same directory as
the original .sqlj source file (not under the current directory). If you specifically want
the output directory to be the same as your .sqlj source directory (perhaps overriding
other -dir settings, such as in properties files), then you can use the -dir option as
follows:
-dir=
Note:
If you specify the -dir option but not the -d option, then generated .class
files will also be placed in the directory specified by -dir, but generated .ser
files will be placed in the directory of the .sqlj file.

-dir=directory_path
For example:
-dir=/topleveldir/mydir
sqlj.dir=directory_path
For example:
sqlj.dir=/topleveldir/mydir
This option does not have any default value.
9.2.3 Connection Options

You can use the following options for the database connection for online semantics-
checking:
• -user
• -password
• -url
• -default-url-prefix
• -driver
• driver_name
There is no requirement for the SQLJ translator to connect to the same database or
schema as the application does at run time. The connection information in application
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source code can be independent of the connection information in the SQLJ options.
In fact, the deployment environment might be unavailable during development and
testing.
Online Semantics-Checking and User Name (-user)

Simple semantics-checking not involving a database connection is referred to as
offline checking. The more thorough semantics-checking requiring a connection is
referred to as online checking. Online checking offers one of the prime advantages of
the SQLJ strong-typing paradigm, namely that type incompatibilities that would usually
result in run-time SQL exceptions are caught during translation, before users ever run
the application.
The -user option enables online semantics-checking and specifies the user name
(schema name) for the exemplar schema, which is the sample database schema that
you provide to the translator for it to use in performing the checking. You can also use
the -user option to specify the password and URL, as opposed to using the -password
and -url options separately.
Note that there is no other flag to enable or disable online semantics-checking. SQLJ
enables or disables it according to the presence or absence of the -user option.
Note:
• Some settings of the SQLJ -parse option will disable online semantics-
checking, overriding the effect of the -user option.
• For compatibility with the loadjava utility, -u is recognized as equivalent
to -user when specified on the command line.
• User names cannot contain the characters / or @.
• You are allowed to use a space instead of = in a user name setting on
the command line, as in the following examples:
-user HR/password
-user@CtxClass HR/password
-u HR/password
-u@CtxClass HR/password
• If a password contains the character @, then you cannot set the
password through the -user option. You must use separate -user and
-password settings.
• If your login name is a member of the DBA group, you may have special
privilege to connect as SYSDBA to the SYS schema. In this case, you can
specify the user name SYS or INTERNAL.
• For ISO code generation, the translator -user setting is forwarded to the
profile customizer, but can be overridden by the customizer user setting.
The most basic usage of the -user option is as follows:

-user=HR
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When you are using only the default connection or other instances of the
DefaultContext class, such a setting will apply to all your SQLJ executable
statements. This example results in online checking against the HR schema.
You can also specify the password, URL, or both along with the user name, using
syntax as in the following examples (with / preceding the password and @ preceding
the URL):
-user=HR/password
-user=HR@jdbc:oracle:oci:@
-user=HR/password@jdbc:oracle:oci:@
Otherwise, the URL can be specified through the -url option, and the password can
be specified interactively or through the -password option.
You can disable online semantics-checking by setting the -user option to an empty
string, as follows:
-user=
Again, when you are using only the default connection or other instances of the
DefaultContext class, this will apply to all your SQLJ executable statements.
Disabling online semantics-checking is useful, for example, if you have online

checking enabled in a properties file, but want to override that on the command
line, or have it enabled in the default properties file but want to override that in a
user-specified properties file, specified using the -props option.
There is also a special user name, URL.CONNECT, which you can use when the URL
specifies the user and password as well as the other details of the connection.
If you declare and use additional connection context classes in your application, then
you can specify -user settings for the testing of SQLJ executable statements that
use instances of those classes. Specify a user name for online checking against a
particular connection context class, for example, CtxClass, as follows:
-user@CtxClass=HR
This results in online checking against the HR schema for any of your SQLJ executable
statements that specify a connection context instance of CtxClass.
As with the default connection context class, you can also specify the password or
URL in your -user setting for a particular connection context class, as in the following
example:
-user@CtxClass=HR/password@jdbc:oracle:oci:@
The CtxClass connection context class must be declared in your source code or
previously compiled into a .class file.
Use the -user option separately for each connection context class for which you want
to enable online checking and set a user name. These settings have no influence on
each other. For example:
-user@CtxClass1=user1 -user@CtxClass2=user2 -user@CtxClass3=user3
When you are using multiple connection context classes in your application, a -user
setting that does not specify a class will apply to the DefaultContext class as well
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as to all classes for which you do not otherwise specify a -user setting. Presumably,
though, you will specify a -user setting for each connection context class, given that
different connection context classes are typically intended for use with different sets of
SQL objects.
Consider a situation where you have declared connection context classes CtxClass1,
CtxClass2, and CtxClass3 and you set -user as follows:
-user@CtxClass2=HR/password -user=bill/lion
Any statement in your application that uses an instance of CtxClass2 will be checked
against the HR schema. Any statement that uses an instance of DefaultContext,
CtxClass1, or CtxClass3 will be checked against the bill schema.
In addition, once you enable online checking by setting the -user option, you can
disable online checking for a particular connection context by setting the -user option
again with an empty user name for that connection context. For example, consider the
following setting:
-user@CtxClass2=
This disables online semantics-checking for any SQLJ executable statements that
specify a connection object that is an instance of CtxClass2.
You can disable online semantics-checking for the default connection context class
and any other connection context classes for which you do not specify a user name as
follows:
-user=
The general command-line syntax for this option is as follows:

-user<@conn_context_class>=username</password><@url>
For example:
-user=HR
-user=HR/password
-user=HR@jdbc:oracle:oci:@
-user=HR/password@jdbc:oracle:oci:@
-user=
-user=URL.CONNECT
-user@CtxClass=HR/password
-user@CtxClass=
sqlj.user<@conn _context_class>=username</password><@url>
For example:
sqlj.user=HR
sqlj.user=HR/password
sqlj.user=HR@jdbc:oracle:oci:@
sqlj.user=HR/password@jdbc:oracle:oci:@
sqlj.user=
sqlj.user=URL.CONNECT
sqlj.user@CtxClass=HR/password
sqlj.user@CtxClass=
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This option does not have a default value. By default, there is no online-semantics
checking.
Note:
Be aware of the difference in format between specifying user, password, and
URL in the user option and specifying them in the -url option. In the -url
option, the user name and password are included in the URL, immediately
following the JDBC driver type. In the -user option they precede the URL.
User Password for Online Semantics-Checking (-password)

The -password option specifies the user password for the database connection for
online semantics-checking. For the -password setting to be meaningful, the -user
option must also be set.
You can also specify the password as part of the -user option setting. Do not use the
-password option for a connection context class if you have already set its password in
the -user option, which takes precedence.
For the most part, functionality of the -password option parallels that of the -user
option. That is, if your application uses only the default connection or other instances
of DefaultContext, then the following will set the password for the schema to be used
in checking all of your SQLJ statements:
-password=password
If you declare and use additional connection context classes, CtxClass1 for example,
then you will presumably use the -user option to specify additional exemplar schemas
to use in testing statements that use those connection context classes. Similarly, use
the -password option to specify passwords for those schemas, as in the following
example:
-password@CtxClass1=password
A connection context class without a password setting, either through the -password
setting or the -user setting, uses the password setting for the default connection
context class. If you set no password for the default connection context class, then
SQLJ prompts you interactively for that password. If you also set no password for a
user-defined connection context class, then SQLJ prompts you interactively for that
password as well. An exception to this discussion is where user name URL.CONNECT is
used. In this case, user name and password are determined from the string specified
in the -url setting and any setting of the -password option is ignored.
You can specifically set an empty password to override other settings of the -password
option, such as in a properties file, and be prompted interactively. You can do this
for the DefaultContext class or any particular connection context class, as in the
following examples:
-password=
-password@CtxClass1=
If you actually want to use an empty password to log in, specify EMPTY.PASSWORD as in
the following examples:
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-password=EMPTY.PASSWORD
-password@CtxClass2=EMPTY.PASSWORD
However, Oracle Database 12c Release 1 (12.1) does not permit an empty password.
Note:
• When specified on the command line, -p is recognized as equivalent to

-password.
• You are allowed to use a space instead of = in a password setting on the
command line, as in the following examples:
-password password
-password@CtxClass password
-p password
-p@CtxClass password
• For ISO code generation, the translator -password setting is forwarded to
the profile customizer, but can be overridden by the customizer password
setting.
The command-line syntax for this option is as follows:

-password<@conn_context_class>=user_password
For example:
-password=password
-password=
-password=EMPTY.PASSWORD
-password@CtxClass=password
sqlj.password<@conn_context_class>=user_password
For example:
sqlj.password=hr
sqlj.password=
sqlj.password=EMPTY.PASSWORD
sqlj.password@CtxClass=hr
This option does not have a default value. Either the password for DefaultContext is
used or the user is prompted.
Connection URL for Online Semantics-Checking (-url)

The -url option specifies a URL for establishing a database connection for online
semantics-checking. As necessary, the URL can include a host name, port number,
and database service name (or SID, which is deprecated in Oracle Database 12c
Release 1 (12.1)).
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You can also specify the URL as part of the -user option setting. Do not use the -url
option for a connection context class if you have already set its URL in the -user
option, which takes precedence.
For the most part, functionality of the -url option parallels that of the -user option.
That is, if your application uses only the default connection or other instances of
DefaultContext, then the following example would set the URL to use for the
connection for checking all your SQLJ statements:
-url=jdbc:oracle:oci:@
Alternatively, to include the host name, port number, and service name:
-url=jdbc:oracle:thin:@myhost:5221/myservice
If you do not begin a URL setting with jdbc:, then the setting is assumed to be of
the form host:port/servicename and, by default, is automatically prefixed with the
following:
jdbc:oracle:thin:@
A -url setting of localhost:5221/myservice would result in the following URL:

jdbc:oracle:thin:@localhost:5221/myservice
You can remove or alter this default prefix with the -default-url-prefix option.
You can specify the user and password in the -url setting, instead of in the -user and
-password settings. In such a case, set -user to URL.CONNECT, as follows:
-url=jdbc:oracle:oci:HR/hr@ -user=URL.CONNECT
If you declare and use additional connection context classes, CtxClass1 for example,
you will presumably specify additional exemplar schemas to use in testing statements
that use those connection context classes. You can use the -url option to specify
URLs for those schemas, as in the following example:
-url@CtxClass1=jdbc:oracle:oci:@
Any connection context class without a URL setting, either through the -url setting
or the -user setting, uses the URL setting for the default connection context class,
presuming a URL has been set for the default context class.
Note:
• Remember that any connection context class with a URL setting must
also have a user name setting for online checking to occur.
• You are allowed to use a space instead of = in a URL setting on the
command line, as in the following examples:
-url jdbc:oracle:oci:@
-url@CtxClass jdbc:oracle:oci:@
• For ISO code generation, the translator -url setting is forwarded to the
profile customizer, but can be overridden by the customizer url setting.
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-url<@conn_context_class>=URL
For example:
-url=jdbc:oracle:oci:@
-url=jdbc:oracle:thin:@hostname:5221/myservice
-url=jdbc:oracle:oci:HR/password@
-url=hostname:5221/myservice
-url@CtxClass=jdbc:oracle:oci:@
sqlj.url<@conn_context_class>=URL
For example:
sqlj.url=jdbc:oracle:oci:@
sqlj.url=jdbc:oracle:thin:@hostname:5221/myservice
sqlj.url=jdbc:oracle:oci:HR/hr@
sqlj.url=hostname:5221/myservice
sqlj.url@CtxClass=jdbc:oracle:oci:@
The default value for this option is:

jdbc:oracle:oci:@
Note:
Be aware of the difference in format between specifying user, password, and
URL in the -user option and specifying them in the -url option. In the -url
option, the user name and password are included in the URL, immediately
following the JDBC driver type. In the -user option, they precede the URL.
Default URL Prefix (-default-url-prefix)

Use the -default-url-prefix option to alter or remove the default prefix. The
following is the default prefix for any URL setting you specify that does not already
start with jdbc:
jdbc:oracle:thin:@
This enables you to use a shorthand in specifying a URL setting, either in the -user
option or the -url option. It is permissible to specify only the host, port, and service
name (or SID, which is deprecated) of the database. As an example, presume you set
a URL as follows:
-url=myhost:5221/myservice
-user=HR/hr@myhost:5221/myservice
By default, the URL will be interpreted to be the following:

jdbc:oracle:thin:@myhost:5221/myservice
If you specify a full URL that starts with jdbc:, then the default prefix will not be used.
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However, if you want your URL settings to default to the JDBC Oracle Call Interface
(OCI) driver, for example, instead of the JDBC Thin driver, then set the default prefix
as follows:
-default-url-prefix=jdbc:oracle:oci:@
If you do not want any prefix, then set the -default-url-prefix option to an empty
string, as follows:
-default-url-prefix=

-default-url-prefix=url_prefix
For example
-default-url-prefix=jdbc:oracle:oci:@
-default-url-prefix=
sqlj.default-url-prefix=url_prefix
For example:
sqlj.default-url-prefix=jdbc:oracle:oci:@
sqlj.default-url-prefix=

jdbc:oracle:thin:@
JDBC Drivers to Register for Online Semantics-Checking (-driver)

The -driver option specifies the JDBC driver class to register for interpreting JDBC
connection URLs for online semantics-checking. Use this option to specify a driver
class or comma-delimited list of classes. The default, OracleDriver, supports Oracle
JDBC OCI, JDBC Thin, and server-side JDBC drivers for use with Oracle Database
12c Release 1 (12.1).
-driver=driver1<,driver2,driver3,...>
For example:
-driver=oracle.jdbc.OracleDriver
-driver=oracle.jdbc.OracleDriver,sun.jdbc.odbc.JdbcOdbcDriver
sqlj.driver=driver1<,driver2,driver3,...>
For example:
sqlj.driver=oracle.jdbc.OracleDriver,sun.jdbc.odbc.JdbcOdbcDriver

oracle.jdbc.OracleDriver
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Driver Name (sqlj.driver_name)

Use the sqlj.driver_name option in the properties file to set the driver name. You
can set the driver_name attribute for end-to-end diagnosis. The value of this attribute
is not validated. This value is passed directly to the server and is displayed as the
value of the CLIENT_DRIVER column of the V$SESSION_CONNECT_INFO view and the
GV$SESSION_CONNECT_INFO view. The maximum length of this value is 8 characters.
If you do not set this property in the properties file, then the default value for this
property is "SQLJ". You can set this property in the following way:
sqlj.driver_name=MYDRIVER
Note:
This attribute can be set only through the properties file and does not have
an equivalent command-line option.
9.2.4 Options for Reporting and Line-Mapping

The following options specify what types of conditions SQLJ should monitor, whether
to generate real-time error and status messages and whether to include cause and
action information with translator error messages:
• -warn
• -status
• -explain
The following options enable line-mapping from the generated Java .class file back
to the .sqlj source file, so that you can trace run-time errors back to the appropriate
location in your original source code:
• -linemap
• -jdblinemap
Use -jdblinemap in conjunction with the Sun Microsystems jdb debugger. Otherwise,
use -linemap.
Translator Warnings (-warn)

There are various warnings and informational messages that the SQLJ translator can
display as dictated by conditions it encounters during the translation. The -warn option
consists of a set of flags that specify which of those warnings and messages should be
displayed, in other words, which conditions should be monitored and which should be
ignored. All the flags for this option must be combined into a single, comma-delimited
string.
Table 9-3 lists the conditions that can be tested, what the true and false flag values
are for each condition, what a true flag value means, and which value is the default.
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Table 9-3 Tests and Flags for SQLJ Warnings
Test and Flag Functions TRUE/FALSE Values

Test for requirement of subtypes of declared object type in an inheritance hierarchy: cast (default)
Enable cast to receive warnings when usage of SQL object types in a SQL inheritance nocast
hierarchy requires that subtypes of a declared type must be passed at run time.
Data precision test: Enable precision to receive warnings if there was a possible loss precision (default)
of precision when moving values from database columns to Java host variables. noprecision
Conversion loss test for nullable data: Enable nulls to receive warnings if there was nulls (default)
possible conversion loss when moving nullable columns or nullable Java types from nonulls
database columns to Java host variables.
Portability test: Enable portable to check SQLJ clauses for portability and receive portable
warnings if there are nonportable clauses. (Where nonportable refers to the use of noportable (default)
extensions to the SQLJ standard, such as vendor-specific types or features.)
Strict matching test for named iterators: Enable strict to instruct SQLJ to require strict (default)
that the number of columns selected from the database must equal the number of nostrict
columns in the named iterator being populated. A warning is issued for any column
in the database cursor for which there is no corresponding column in the iterator.
The nostrict setting allows more (but not fewer) columns in the database cursor.
Unmatched columns are ignored.
Translation-time informational messages: Enable verbose to provide additional verbose
informational messages about the translation process, such as what database noverbose (default)
connections were made for online checking.
Global enabling or disabling of warnings: Use all or none to enable or disable all all
warnings. none
The verbose/noverbose flag works differently from the others. It does not enable
a particular test but enables output of general informational messages about the
semantics-checking.
Note:
Do not confuse -warn=verbose with the -status flag. The -status
flag provides real-time informational messages about all aspects of
SQLJ translation: translation, semantics-checking, compilation, and profile
customization, if applicable. The -warn=verbose flag results in additional
reporting about the translation phase only.
The global all/none flag takes priority over default settings. You can use it to enable
or disable all flags, or to serve as an initialization to ensure that all flags are off before
you turn selected flags on, or all flags are on before you turn selected flags off.
The all setting is equivalent to the following:
cast,precision,nulls,portable,strict,verbose
And the none setting is equivalent to the following:

nocast,noprecision,nonulls,noportable,nostrict,noverbose
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There is no default for all/none. There are only defaults for individual flags.
Following are some examples:

• Use the following sequence to ensure that only the nulls flag is on:
-warn=none,nulls
• The following sequence will have the same result, because the verbose setting will
be overridden:
-warn=verbose,none,nulls
• Use the following to ensure that everything except the portability flag is on:
-warn=all,noportable
• This sequence will have the same result, because the nonulls setting will be
overridden:
-warn=nonulls,all,noportable
Other than placement of the all/none flag, the order in which flags appear in a -warn
setting is unimportant, except in the case of conflicting settings. If there are conflicts,
such as in -warn=portable,noportable, then the last (right-most) setting is used.
Separate settings of the -warn option in properties files and on the command line
are not cumulative. Only the last setting is processed. In the following example, the
-warn=portable setting is ignored. That flag and all other flags besides nulls/nonulls
are set according to their defaults:
-warn=portable -warn=nonulls
Note:
The cast, precision, nullability, and strictness tests are part of online
semantics-checking and require a database connection.

-warn=comma-delimited_list_of_flags
For example:
-warn=none,nulls,precision
sqlj.warn=comma-delimited_list_of_flags
For example:
sqlj.warn=none,nulls,precision
The default value for this option is as follows:

cast,precision,nulls,noportable,strict,noverbose
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Real-Time Status Messages (-status)

The -status flag instructs SQLJ to display additional status messages throughout
all aspects of the SQLJ process: translation, semantics-checking, compilation, and
customization. Messages are displayed as each file is processed and at each stage of
the SQLJ operation.
Note:
• Do not confuse -warn=verbose with the -status flag. The -status flag
provides real-time informational messages about all aspects of SQLJ
translation. The -warn=verbose flag results in additional reporting about
the translation phase only.
• For compatibility with the loadjava utility, -v is recognized as equivalent
to -status when specified on the command line.

-status<=true|false>
For example:
-status
sqlj.status<=true|false>
For example:
sqlj.status

false
Cause and Action for Translator Errors (-explain)

The -explain flag instructs the SQLJ translator to include cause and action
information, as available, with translator error message output for the first occurrence
of each error.
-explain<=true|false>
For example:
-explain
sqlj.explain<=true|false>
For example:
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sqlj.explain

false
Line-Mapping to SQLJ Source File (-linemap)

The -linemap flag instructs SQLJ to map line numbers from a SQLJ source code file
to locations in the corresponding .class file. This will be the .class file created during
compilation of the .java file generated by the SQLJ translator. As a result, when Java
run-time errors occur, the line number reported by the JVM is the line number in the
SQLJ source code, making it much easier to debug.
Usually, the instructions in a .class file map to source code lines in the
corresponding .java file. This would be of limited use to SQLJ developers, though, as
they would still need to map line numbers in the generated .java file to line numbers
in their original .sqlj file.
The SQLJ translator modifies the .class file to implement the -linemap option,
replacing line numbers and the file name from the generated .java file with
corresponding line numbers and the file name from the original .sqlj file. This process
is known as instrumenting the class file.
In performing this, SQLJ takes the following into account:
• The -d option setting, which determines the root directory for .class files
• The -dir option setting, which determines the root directory for generated .java
files
Note:
• If you are processing a .sqlj file and the compilation step is skipped
due to error, then no line-mapping can be performed either, because
no .class file is available for mapping.
• When the Java compiler is invoked from SQLJ, it always reports
compilation errors using line numbers of the original .sqlj source file,
not the generated .java file. No option needs to be set for this mapping.
• Anonymous classes in a .sqlj file will not be instrumented.
• If you are using the Sun Microsystems jdb debugger, then use the
-jdblinemap option instead of the -linemap option.

-linemap<=true|false>
For example:
-linemap
sqlj.linemap<=true|false>
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For example:
sqlj.linemap

false
Line-Mapping to SQLJ Source File for jdb Debugger (-jdblinemap)

This option is equivalent to the -linemap option, but you should use it instead of
-linemap if you are using the Sun Microsystems jdb debugger. This is because jdb
can access only source files with a .java file name extension.
With the -jdblinemap setting, SQLJ does the following:
• Overwrites the contents of the .java file generated by the translator with the
contents of the original .sqlj file
• Preserves the .java file name, instead of the .sqlj file name, in the
generated .class file
In this way, the SQLJ source code is accessible to jdb.

-jdblinemap<=true|false>
For example:
-jdblinemap
sqlj.jdblinemap<=true|false>
For example:
sqlj.jdblinemap

false
9.2.5 Options for DMS

The Oracle SQLJ implementation provides translator front-end options to support
DMS:
• -instrument: Enable instrumentation and designate a name for the application
(the collective of the components being translated).
• -components: Specify the components (packages and classes) to be instrumented.
See Also:
"SQLJ Support for Oracle Performance Monitoring"
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Instrumentation for DMS (-instrument)

Use the SQLJ -instrument option to enable instrumentation and specify an
application name. In this context, the term application refers to all the SQLJ and Java
components specified for translation in the SQLJ command line.
Possible settings of the -instrument option are as follows:
• application_name: To enable instrumentation and use the specified application

name, optionally prefixed with a package name in the standard Java dot syntax.
Use a slash (/), with no spaces, between the package name and the application
name.
• true: To enable instrumentation and use the default application name,
defaultApp.
• false (default): To disable instrumentation.
If instrumentation is enabled, a SQLJ DMS properties file is created. Its name and
location are according to the -instrument setting, starting from the current directory,
according to the package name and also according to any setting of the SQLJ -d
option. If no application name is specified, as is the case with the setting true, then
the properties file is named sqlmonitor.properties in the current directory.
As a simple example, a setting of -instrument=myapp will result in creation of the

properties file, myapp.properties, in the current directory.
Now consider the following example, for an application name of stock and the
package com.acme:
% sqlj -instrument=com.acme/stock Stock.sqlj Trading.sqlj
In this case, the properties file ./com/acme/stock.properties is created.
Now consider the following example:

% sqlj -instrument=com.acme/stock -d /home Stock.sqlj Trading.sqlj
In this case, because of the -d option, the file /home/com/acme/stock.properties is

created.
You can also set the -instrument option in sqlj.properties as follows:
sqlj.instrument=com.acme/stock
Note:
A setting of -instrument is equivalent to -instrument=true.

-instrument<=true|false|application_name>
For example:
-instrument=com.acme/stock
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sqlj.instrument<=true|false|application_name>
For example:
sqlj.instrument=com.acme/stock

false
Components to Instrument for DMS (-components)

When instrumentation is enabled through the -instrument option, use the -
components option to specify the components to be instrumented for DMS monitoring.
This is a subset of the components being translated, typically most or all of them to
allow flexibility in what you can monitor during run time. At run time, instrumented
components are monitored according to what is specified in the SQLJ DMS properties
file.
See Also:
"SQLJ Run-Time Commands and Properties File Settings for DMS"
Note that any components that are not instrumented during translation cannot be
monitored during run time, regardless of what is specified in the properties file.
The -components option supports either of the following settings:
• list_of_components: A comma-delimited list of packages or classes to instrument

• all (default): Specification to instrument all components being translated
For the list of components, you can specify fully qualified class names, using the
standard Java dot syntax, or you can specify package names to instrument all classes
in the packages.
For example, to instrument the Stock and Trading classes:
% sqlj ... -components=com.acme.Stock,com.acme.Trading
Alternatively, here is an equivalent specification in the sqlj.properties file:

sqlj.components=com.acme.Stock,com.acme.Trading

-components=all|list_of_components
For example:
-components=com.acme.Stock,com.acme.Trading
sqlj.components=all|list_of_components
For example:
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sqlj.components=com.acme.Stock,com.acme.Trading

all
9.2.6 Options for Code Generation, Optimizations, and CHAR

Comparisons
By default, the Oracle SQLJ implementation uses Oracle-specific code generation,
which generates Oracle JDBC code directly, as an alternative to ISO standard code
generation. With Oracle-specific code generation, no profiles are generated, and the
SQLJ run time is largely bypassed during code execution.
Because profile customization is not applicable with Oracle-specific code generation,
some generally useful optimization options, formerly available only through Oracle
customizer, are now available directly through the SQLJ translator.
There is also an option for CHAR comparisons in a WHERE clause, accounting for any
blank padding in the column. This option is also available as either a translator option
(for Oracle-specific code generation) or an Oracle customizer option (for ISO standard
code generation).
This section describes the following code generation, optimization, and CHAR
comparison and bind options:
• -codegen
• -optcols
• -optparams
• -optparamdefaults
• -fixedchar
• -ncharconv
Code Generation (-codegen)

The Oracle SQLJ implementation can either generate Oracle-specific JDBC code
directly or generate ISO standard code that calls the SQLJ run time, which in turn calls
JDBC. With Oracle-specific code generation, there are no profile files and the SQLJ
run time is largely bypassed during program execution.
If you want to specify code generation according to the ISO standard, then use the
SQLJ translator -codegen option as follows:
-codegen=iso
The default is Oracle-specific SQLJ code generation, but you can also explicitly
specify this as follows:
-codegen=oracle
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Note:
When codegen=iso, translator settings for -user, -password, -url, -
optparams, -optparamdefaults, and -fixedchar are forwarded to the profile
customizer as well. However, if you want to override these settings for
customization, particularly for -user, -password, and -url, then you can do
so by setting the customizer options directly.

-codegen=iso|oracle
For example:
-codegen=iso
The syntax for as properties file entry for this option is as follows:
sqlj.codegen=iso|oracle
For example:
sqlj.codegen=iso

oracle
Column Definitions (-optcols)

Use the SQLJ translator -optcols flag to instruct the translator to determine types and
sizes of iterator or result set columns. This enables registration of the columns with
Oracle JDBC driver when your application runs, saving round trips to the database,
depending on the particular driver implementation. Specifically, this is effective for the
JDBC Thin driver and positional iterators.
See Also:
"Column Definitions"
Note:
This translator option is equivalent to the optcols Oracle customizer option
and was created for the default Oracle-specific code generation scenario,
where there are no profiles. But it is also applicable for ISO standard code
generation. In this case, setting the translator option will automatically set the
customizer option as well.
You can enable or disable this flag on the SQLJ command line or in a properties file.
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Enable it on the command line as follows:

-optcols
or:
-optcols=true
This flag is disabled by default, but you can also disable it explicitly. Disable it on the
command line as follows:
-optcols=false
Column definitions require a database connection for examination of the columns of

tables being queried, so the SQLJ translator -user, -password, and -url options must
also be set appropriately. For example:
% sqlj -user=HR@jdbc:oracle:oci:@ -optcols MyApp.sqlj
Password: password
Note:
• Because definitions are created for all columns that you select, it is
advisable in your SQL operations to explicitly select the columns you will
use, rather than using the SELECT * syntax, if you may not actually use
all the columns selected. A situation where you select more than you
need exposes you to a greater risk of run-time errors, if any changes
were made to the table between customization and run time, especially
when you have customized with column definitions. You may want to
translate with the SQLJ -warn=strict flag set, which will warn you if
additional (unwanted) columns will be selected by your query.
• Column definitions are not possible for any iterator or result set that
includes one or more object or collection columns.
• An error will be generated if you enable the -optcols option without
setting the user name, password, and URL for a database connection.
• The translator does not have to connect to the same schema or even the
same database that your application will connect to at run time, but the
relevant columns will have to be in the same order and of identical types
and sizes to avoid run-time errors.

-optcols<=true|false>
For example:
-optcols
sqlj.optcols<=true|false>
For example:
sqlj.optcols
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false
Parameter Definitions (-optparams)

Use the SQLJ translator -optparams flag to enable parameter size definitions. If this
flag is enabled, SQLJ will register your input and output parameters to optimize JDBC
resource allocations according to sizes you specify, with the following precedence:
1. Size specified in a source code hint, if any
2. Default size, if any, specified for the corresponding data type in the -
optparamdefaults option setting
If there is no source code hint or default data type size for a given host variable, then
resource allocation is left to JDBC.
See Also:
"Column Definitions"
Note:
This translator option is equivalent to the optparams Oracle customizer
option. It was created for the default Oracle-specific code generation
scenario, where there are no profiles. But it is also applicable for ISO
standard code generation. In this case, setting the translator option will
automatically set the customizer option as well.
You can enable or disable the -optparams flag on the command line or in a SQLJ
properties file.
-optparams
or:
-optparams=true
-optparams=false
Note:
Unlike the -optcols option, the -optparams option does not require a
database connection, because you are providing the size specifications
yourself.
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Following is a command-line example (omitting a setting for the -optparamdefaults

option):
% sqlj -optparams -optparamdefaults=defaults_string MyApp.sqlj

-optparams<=true|false>
For example:
-optparams
sqlj.optparams<=true|false>
For example:
sqlj.optparams

false
Parameter Default Size (-optparamdefaults)

If you enable the -optparams option to set parameter sizes, then use the -
optparamdefaults option as desired to set default sizes for specified data types. If
-optparams is not enabled, then any -optparamdefaults setting is ignored.
If a host variable has a source code hint to specify its size, then that takes precedence
over the corresponding data type default size set with this option. If there is no source
code hint or corresponding data type default size for a particular host variable, then
resource allocation for that variable is determined by the JDBC driver, just as it would
be if -optparams were not enabled.
There is no requirement to use the -optparamdefaults option, although it is typically

used whenever -optparams is enabled. If -optparams is enabled and there are no
default size settings, then resources are allocated either according to source code
hints, if any, or according to the JDBC driver.
See Also:
"Parameter Size Definitions"
Note:
This translator option is equivalent to the optparamdefaults Oracle
customizer option. It was created for the default Oracle-specific code
generation scenario, where there are no profiles. But it is also applicable
for ISO standard code generation. In this case, setting the translator option
will automatically set the customizer option as well.
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You can set the -optparamdefaults flag on the command line or in a SQLJ properties
file.
Set it on the command line as follows:
-optparamdefaults=datatype1(size1),datatype2(size2),...
All sizes are in bytes. Do not include any white space. Use empty parentheses for a
null setting.
For example, the following will set sizes of 30 bytes for VARCHAR2 and 1000 bytes
for RAW, and will specify a null size setting for CHAR. So, for any host variable
corresponding to the CHAR data type, if there is no source code hint, then the JDBC
driver is left to allocate the resources.
-optparamdefaults=VARCHAR2(30),RAW(1000),CHAR()
The -optparamdefaults option recognizes the following data type names:
• CHAR
• VARCHAR, VARCHAR2 (synonymous)
• LONG, LONGVARCHAR (synonymous)
• BINARY, RAW (synonymous)
• VARBINARY
• LONGVARBINARY, LONGRAW (synonymous)
The -optparamdefaults option also recognizes group names and wildcards, as
follows:
• CHAR_TYPE covers CHAR, VARCHAR/VARCHAR2, and LONG/LONGVARCHAR.
• RAW_TYPE covers BINARY/RAW, VARBINARY, and LONGVARBINARY/LONGRAW.
• A percent sign (%) by itself covers all recognized data types or appended to a
partial name, covers a subset of data types. For example, VAR% includes all data
types that start with "VAR".
The -optparamdefaults setting is processed from left to right. When using group
names or wildcards, you can override a group setting for particular data types.
The following example sets a general default size of 50 bytes, overrides that with a
setting of 500 bytes for raw types, then overrides the raw type group setting with a null
setting for VARBINARY (leaving that to JDBC for corresponding host variables with no
source code hints):
-optparamdefaults=%(50),RAW_TYPE(500),VARBINARY()
Following is a command-line example, including the -optparams setting as well:

% sqlj -optparams -optparamdefaults=CHAR_TYPE(50),RAW_TYPE(500),CHAR(10)
MyApp.sqlj
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Note:
If at run time the actual size exceeds the registered size of any parameter,
then run-time errors will occur.

-optparamdefaults=defaults_string
For example:
-optparamdefaults=VAR%(50),LONG%(500),RAW_TYPE()
sqlj.optparamdefaults=defaults_string
For example
sqlj.optparamdefaults=VAR%(50),LONG%(500),RAW_TYPE()

null
CHAR Comparisons with Blank Padding (-fixedchar)

Set this flag to true to account for blank padding in CHAR database columns when
binding character strings for WHERE clause comparisons. This way, for example,
"mystring" would compare positively against "mystring ".
This functionality uses the JDBC setFixedCHAR() method, an Oracle extension to take
padding into account. The standard JDBC setString() method does not account for
blank padding.
Following is an example of -fixedchar usage:
% sqlj -fixedchar MyProgram.sqlj AnotherProg.java ...
Note:
• This translator option is equivalent to the fixedchar Oracle customizer

option. It was created for the default Oracle-specific code generation
scenario, where there are no profiles. But it is also applicable for ISO
standard code generation. In this case, setting the translator option will
automatically set the customizer option as well.
• In CHAR or VARCHAR2 columns, the Oracle SQL implementation treats the
values NULL and ''" (empty string) synonymously. Unfortunately, however,
while you can insert the string "", you cannot successfully compare
against it without using IS NULL syntax. Using -fixedchar functionality
does not resolve this issue.
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-fixedchar<=true|false>
For example:
-fixedchar
sqlj.fixedchar<=true|false>
For example:
sqlj.fixedchar

false
NCHAR Bind (-ncharconv)

Set this option if you want to use String host variables to bind to NCHAR columns. This
option specifies that the SetFormOfUse method should be used in the generated code
for all binds to character columns. You need to translate the SQLJ file with is option as
follows:
% sqlj -ncharconv MyApp.sqlj AnotherApp.java ...
This option is supported by both codegen=oracle and codegen=iso.
Note:
• When the SQLJ file is compiled with the -ncharconv option,

the setFormOfUse method is used in the generated code for
codegen=oracle. For codegen=iso, this option information is passed to
Oracle SQLJ run time, which internally uses SetFormOfUse for bind at run
time.
• This translator option is not available in database releases prior to
Oracle Database 10g Release 2 (10.2).

-ncharconv<=true|false>
For example:
-ncharconv
sqlj.ncharconv<=true|false>
For example:
sqlj.ncharconv
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Advanced Translator Options
false
9.3 Advanced Translator Options

This section documents the syntax and functionality of the advanced flags and options
you can specify in running SQLJ, as well as prefixes used to pass options to the JVM,
Java compiler, or SQLJ profile customizer. These options enable you to exercise any
of the specialized features of the Oracle SQLJ implementation. For options that can
also be specified in a properties file, that syntax is noted as well.
• Prefixes that Pass Option Settings to Other Executables
• Flags for Special Processing
• Semantics-Checking and Offline-Parsing Options
9.3.1 Prefixes that Pass Option Settings to Other Executables

The following flags mark options to be passed to the Java interpreter, Java compiler,
and SQLJ profile customizer:
• -J (mark options for the Java interpreter)
• -C (mark options for the Java compiler)
• -P (mark options for the profile customizer, for ISO code generation only)
Options to Pass to the Java Virtual Machine (-J)

The -J prefix, specified on the command line, marks options to be passed to the JVM
from which SQLJ was invoked. This prefix immediately precedes a JVM option, with
no spaces in between. After stripping off the -J prefix, the sqlj script passes the Java
option to the JVM. For example:
-J-Duser.language=ja
After stripping the -J prefix, the sqlj script passes the -Duser.language=ja argument
as is to the JVM. In the Sun Microsystems JDK, the
-Duser.language=ja flag sets the user.language system property to the value ja
(Japanese), but specific flags are dependent on the actual Java executable you are
using and are not interpreted or acted upon by the sqlj script in any way.
You cannot pass options to the JVM from a properties file, because properties files are
read after the JVM is invoked.
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Note:
• While it is not possible to use a properties file to pass options directly

to the JVM in which the SQLJ translator runs, it is possible to use the
SQLJ_OPTIONS environment variable for this purpose. It is also possible,
if applicable, to use a properties file to pass options to the JVM in which
the Java compiler runs.
• The JVM file.encoding setting does not apply to Java properties files.
Properties files always use the encoding 8859_1. This is a feature of
Java in general, not SQLJ in particular. However, you can use Unicode
escape sequences in a properties file. You can use the native2ascii
utility to determine escape sequences.

-J-Java_option
For example:
Options to Pass to the Java Compiler (-C)

The -C prefix marks options to pass to the Java compiler invoked from the sqlj script.
This prefix immediately precedes a Java compiler option, with no spaces in between.
After stripping off the -C prefix, the sqlj script passes the compiler option to the Java
compiler. For example:
-C-nowarn
After stripping the -C prefix, the sqlj script passes the -nowarn argument as is to the
compiler.
Generally, compiler options are passed without change, but when you use an equal
sign (=) to set a compiler option that takes a value, such as for -bootclasspath,
-extdirs, or -target, the equal sign is stripped out when the option is passed to the
compiler. Consider the following example:
% sqlj -C-bootclasspath=/usr/local/packages/jdk6/jre/lib/rt.jar myfile.sqlj
Also note that if the Java compiler runs in its own JVM, then you can pass options to
that JVM through the compiler. Accomplish this by prefixing the JVM option with
-C-J with no spaces between this prefix combination and the option. For example:
-C-J-Duser.language=de
Observe the following restrictions in using the -C prefix:
• Do not use -C-encoding to specify encoding of .java files processed by the

Java compiler. Instead, use the SQLJ -encoding option, which specifies encoding
of .sqlj files processed by SQLJ and .java files generated by SQLJ, and is also
passed to the compiler. This ensures that .sqlj files and.java files receive the
same encoding.
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• Do not use -C-d to specify an output directory for .class files. Instead, use the
SQLJ -d option, which specifies the output directory for generated profile files
(.ser), and is also passed to the Java compiler. This will ensure that .class files
and .ser files are in the same directory.
Note:
• If you specify compiler options but disable compilation (-compile=false),

then the compiler options are silently ignored.
• The compiler help option (-C-help, presuming your compiler supports -
help) can be specified only on the command line or in the SQLJ_OPTIONS
variable, not in a properties file. As with the SQLJ -help option, no
translation will be done. This is true even if you also specify files to
process. SQLJ assumes that you want help or you want translation, but
not both.

-C-Java_compiler_option
For example:
-C-nowarn
compile.Java_compiler_option
For example:
compile.nowarn
Options to Pass to the Profile Customizer (-P)

During the customization phase (relevant only for ISO standard code generation),
the sqlj script invokes a front-end customizer harness, which coordinates the
customization and runs your particular customizer. The -P prefix marks options for
customization, as follows:
• Use -P by itself to pass generic options to the customizer harness that apply
regardless of the customizer.
• Use -P-C to pass vendor-specific options to the particular customizer you are
using.
The -P and -P-C prefixes immediately precede a customizer option, with no spaces in
between. After stripping off the prefix, the sqlj script passes the customizer option as
is to the profile customizer.
One use of the -P prefix is to override the default customizer determined by the SQLJ
-default-customizer option, as follows:
-P-customizer=your_customizer_class
Example of a generic customizer option:
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-P-backup
The -backup flag is a generic customizer option to backup the previous customization
before generating a new one.
Following is an example of a vendor-specific customizer option (in this case, Oracle-
specific):
-P-Csummary
The summary flag is an Oracle customizer option that prints a summary of the
customizations performed.
Note:
• There is no hyphen between -P-C and a vendor-specific customizer

option. With other prefixes and prefix combinations, there is a hyphen
between the prefix and the option.
• The customizer help option (-P-help) can be specified only on the
command line or in the SQLJ_OPTIONS variable, not in a properties file.
As with the SQLJ -help option, no translation will be done. This is true
even if you also specify files to process. SQLJ assumes that you want
help or you want translation, but not both.
• For ISO code generation, if you specify customization options but turn
off customization for .sqlj files (and have no .ser files on the command
line), then the customization options are silently ignored.
• The -P prefix is not applicable for the default Oracle-specific code
generation, where no profiles are produced and so no customization is
performed.

-P-<C>profile_customizer_option
For example:
-P-driver=oracle.jdbc.OracleDriver
-P-Csummary
profile.<C>profile_customizer_option
For example:
profile.driver=oracle.jdbc.OracleDriver
profile.Csummary
9.3.2 Flags for Special Processing

The .sqlj files are typically processed by the SQLJ translator, the Java compiler, and,
for ISO code generation, the SQLJ profile customizer. The following flags limit this
processing, directing the SQLJ startup script to skip the indicated process:
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• -compile
• -profile
The -ser2class flag, for ISO code generation, directs SQLJ to convert profiles from
serialized resource (.ser) files to class files after customization.
The -checksource flag instructs SQLJ type resolution, in certain circumstances, to

examine source files as well as class files or files specified on the SQLJ command
line.
The -bind-by-identifier flag specifies that SQLJ treat multiple appearances of the
same host variable in a given SQLJ statement as a single bind occurrence.
Compilation Flag (-compile)

The -compile flag enables or disables processing of .java files by the compiler. This
applies both to generated .java files and to .java files specified on the command line.
This flag is useful, for example, if you want to compile .java files later using a compiler
other than javac. The flag is true by default. Setting it to false disables compilation.
When you process a .sqlj file with -compile=false, you are responsible for
compiling and customizing it later as necessary.
Setting -compile=false also implicitly sets -profile=false. In other words, whenever
-compile is false, both compilation and customization are skipped. If you set -
compile=false and -profile=true, then your -profile setting is ignored.
Note:
There are situations where it is sensible for -compile to be set to false even
when .java files must be accessed for type resolution. You may do this,
for example, if you are translating a .sqlj file and want to specify one or
more .java files on the command line for type resolution during translation,
but want to compile all your .java files later using a particular compiler.
Note, however, that the -checksource option can simplify the type resolution
process by eliminating the need to enter .java files for resolution on the
SQLJ command line.

-compile<=true|false>
For example:
-compile=false
sqlj.compile<=true|false>
For example:
sqlj.compile=false
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true
Profile Customization Flag (-profile)

For ISO code generation, the -profile flag enables or disables processing of
generated profile files (.ser) by the SQLJ profile customizer. However, this applies
only to .ser files generated by the SQLJ translator from .sqlj files that you specify
on the current command line. It does not apply to previously generated .ser files (or
to .jar files) that you specify on the command line. The flag is true by default. Setting
it to false disables customization.
This option acts differently than the -compile option for files specified on the command
line. Any .ser and .jar files specified on the command line are still customized if
-profile=false. However, .java files specified on the command line are not compiled
if -compile=false. The reason for this is that you may want other operations, such as
line mapping, to be performed on a .java file. There are, however, no other operations
that can be performed on a .ser or .jar file specified on the command line.
When you process a .sqlj file with -profile=false, you are responsible for
customizing it later, as necessary.
Note:
• Set this option to false if you do not want your application to require
Oracle SQLJ run time and an Oracle JDBC driver when it runs.
Or accomplish this by specifying a nondefault customizer, using the
-default-customizer option. If no customization is performed, then the
generic SQLJ run time will be used when your application runs.
• Setting -compile=false also implicitly sets -profile=false. In other
words, whenever -compile is false, both compilation and customization
are skipped. If you set -compile=false and -profile=true, then your
-profile setting is ignored.
• This option is not applicable for the default Oracle-specific code
generation, where no profiles are produced and so no customization is
performed.

-profile<=true|false>
For example:
-profile=false
sqlj.profile<=true|false>
For example:
sqlj.profile=false
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true
Conversion of .ser File to .class File (-ser2class)

With ISO standard SQLJ code generation, the -ser2class flag instructs SQLJ to
convert generated .ser files to .class files. This is necessary if you are using SQLJ
to create an applet that will be run from a browser that does not support resource file
names with the .ser suffix.
This also simplifies the naming of schema objects for your profiles in situations where
you are translating a SQLJ program on a client and then loading classes and resource
files into the server. Loaded class schema objects have a simpler naming convention
than loaded resource schema objects.
The conversion is performed after profile customization so that it includes your
customizations. The base names of converted files are identical to those of the original
files. The only difference in the file name is .ser being replaced by .class. For
example, consider the following:
Foo_SJProfile0.ser
This is converted to:

Foo_SJProfile0.class
Note:
• The original .ser file is not saved.

• Once a profile has been converted to a .class file, it cannot be further
customized. You would have to delete the .class file and rerun SQLJ to
recreate the profile.
• Where encoding is necessary, the -ser2class option always uses
8859_1 encoding, ignoring the SQLJ -encoding setting.
• If you use the default Oracle-specific code generation, then no profiles
are produced and the -ser2class option does not apply.

-ser2class<=true|false>
For example:
-ser2class
sqlj.ser2class<=true|false>
For example
sqlj.ser2class

false
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Source Check for Type Resolution (-checksource)

It may not be sufficient for the SQLJ type resolution process to examine only class files
in the classpath and class or source files specified on the SQLJ command line. The
-checksource flag instructs SQLJ to also examine source files in the classpath under
the following circumstances:
• If a class file cannot be found for a required class, but a source file can be found
• If a source file has a more recent modification date than its corresponding class
file
Note:
This applies only to Java types that appear in #sql statements, not
elsewhere in your Java code. Therefore, you should always explicitly provide
the names of any required .sqlj files on the SQLJ command line.

-checksource<=true|false>
For example:
-checksource=false
sqlj.checksource=<=true|false>
For example:
sqlj.checksource=false

true
Binding Host Expressions by Identifier (-bind-by-identifier)

In keeping with the SQLJ standard, the Oracle implementation by default creates
a unique name for each host-variable bind reference in a statement, even if there
are multiple occurrences of the same host variable. The SQLJ standard is based on
JDBC, and JDBC does not make provisions for binding the same variable into different
positions. Instead, each bind position (identified by ?) is bound to an individual value.
In some situations this causes errors, such as in the following example:

#sql emps = { SELECT substr(first_name, 1, :bind_var), sum(salary) FROM employees
GROUP BY substr(first_name, 1, :bind_var) };
Because separate bind reference names are created for the two occurrences of
bind_var, this results in a SQL exception at run time. When the differing bind names
are detected, the SQL engine concludes that the GROUP BY clause is not part of the
SELECT-list.
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To avoid such problems, Oracle extends standard functionality with the -bind-by-
identifier flag. A setting of true results in all bind occurrences of the same
identifier in a given SQLJ statement or PL/SQL block being treated as a single bind
occurrence. A SQLJ statement with four bind operations, :x, :x, :y, :x, would be
bound as :1, :1, :2, :1 instead of :1, :2, :3, :4.
In the preceding example, both bindings would be as substr(ename, 1, :1) instead

of as substr(ename, 1, :1) and substr(ename, 1, :2).
Note:
The -bind-by-identifier flag applies only to host expressions that are
simple host variables.

-bind-by-identifier<=true|false>
For example:
-bind-by-identifier
sqlj.bind-by-identifier=<=true|false>
For example:
sqlj.bind-by-identifier

false
9.3.3 Semantics-Checking and Offline-Parsing Options

The following options specify characteristics of online and offline semantics-checking
and offline parsing:
• -offline
• -online
• -cache
• -parse
Description of these options is preceded by two introductory discussions:
• A discussion of OracleChecker (the default front-end class for semantics-
checking) and an introduction to Oracle semantics-checkers
• A comparison of online semantics-checking versus offline parsing
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Note:
Online semantics-checking is enabled by setting the translator -user option.
However, the setting of the -parse option, which is used to enable or disable
offline parsing, can override this.
Semantics-Checkers and OracleChecker Front End (default checker)

Oracle supplies Oracle-specific offline checkers, a generic offline checker, Oracle-
specific online checkers, and a generic online checker. The generic checkers assume
you use only Entry Level of SQL-92 and standard JDBC features. Oracle recommends
that you use Oracle-specific checkers when using Oracle Database.
The default checker, which is satisfactory in the great majority of circumstances, is
oracle.sqlj.checker.OracleChecker for both online and offline checking. This class
acts as a front end and runs the appropriate semantics-checker, depending on your
environment and whether you choose offline or online checking.
For Oracle, there is Oracle8 checker for Oracle 10g, Oracle9i, and Oracle8i
types, for both online and offline checking (as used in the corresponding JDBC
implementations).
Online Checking with Oracle Database and JDBC Driver

If you are using Oracle Database and Oracle JDBC driver with online checking, then
OracleChecker will choose a checker based on the lower of your database version
and JDBC driver version. The following table summarizes the choices for the possible
combinations of database version and driver version, and also notes any other Oracle
checkers that would be legal.
Table 9-4 Oracle Online Semantics-Checkers Chosen by OracleChecker
Database Release JDBC Release Chosen Online Checker Other Legal Online
Checkers
Oracle10g, 9i, or 8i Oracle11g Oracle8JdbcChecker Oracle8To7JdbcChecker
Offline Checking with Oracle JDBC Driver

If you are using an Oracle JDBC driver with offline checking, then OracleChecker
chooses a checker based on your JDBC driver version. The following table
summarizes the possible choices.
Table 9-5 Oracle Offline Semantics-Checkers Chosen by OracleChecker
JDBC Release Chosen Offline Checker Other Legal Offline

Checkers
Oracle11g Oracle8OfflineChecker No
Online Semantics-Checking Versus Offline Parsing

The Oracle SQLJ implementation supports a feature known as offline parsing that
offers a limited alternative to online semantics-checking. Offline parsing does not
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use a database connection, so cannot perform verification of operations against the

database schema, but does offer syntax-checking of all SQL and PL/SQL statements.
(Prior to Oracle9i, syntax-checking was not possible without a database connection.)
The following table provides a comparative summary of what offline parsing and online
semantics-checking offer.
Table 9-6 Feature Comparison: Offline Parsing Versus Online Semantics-

Checking
Feature By Offline Parsing? By Online Checking?

Verify data manipulation language (DML), Yes Yes
SELECT, and PL/SQL syntax.
Verify data definition language (DDL) syntax. Yes No
Verify DML, SELECT, and PL/SQL No Yes
semantics (comparison against database
schema).
Verify DDL semantics (comparison against No No
database schema).
Online checking offers the primary advantage of verifying SQL and PL/SQL operations
against the database schema. This includes verifying that column types match SQL
operations and verifying the existence of called stored procedures. It requires a
database connection during translation, however, which may be problematic in some
circumstances. It also performs no verification of DDL operations.
Offline parsing offers the advantage of SQL syntax-checking without a database
connection during translation, and also includes DDL operations in its syntax
verifications.
Note that neither mode performs DDL semantics-checking against the database
schema.
Note:
• If both offline parsing and online checking are enabled, some types of
errors will be reported twice.
• Problems detected by either the offline parser or the online checker are
reported at a warning or advisory level, not a fatal level.
• Do not confuse offline parsing with offline semantics-checking. Offline
checking consists of basic semantics-checking steps that always occur,
regardless of whether online checking is enabled and regardless of
whether offline parsing is enabled: analysis of the types of Java
expressions in your SQLJ executable statements, and categorization of
embedded SQL operations according to keyword, such as SELECT.
• Compatibility of data corresponding to weakly typed host expressions is
never checked.
• Mode compatibility of expressions in PL/SQL anonymous blocks is never
checked.
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Offline Semantics-Checker (-offline)

The -offline option specifies a Java class that implements the semantics-checking
component of SQLJ for offline checking. With offline checking, there is no database
connection. Only SQL syntax and usage of Java types is checked. Note that offline
checking is neither enabled nor disabled by the -offline option. Offline checking runs
only when online checking does not, either because online checking is not enabled or
because the database connection cannot be established.
You can specify different offline checkers for different connection contexts, with a limit
of one checker per context. Do not list multiple offline checkers for one connection
context. The default OracleChecker, a front-end class, will serve your needs unless
you want to specify a particular checker that would not be chosen by OracleChecker.
The following example shows how to select Oracle8 offline checker for a particular
connection context (CtxClass):
-offline@CtxClass=oracle.sqlj.checker.Oracle8OfflineChecker
This results in SQLJ using oracle.sqlj.checker.Oracle8OfflineChecker for offline

checking of any of your SQLJ executable statements that specify a connection object
that is a CtxClass instance.
The CtxClass connection context class must be declared in your source code
or previously compiled into a .class file. (See "Connection Contexts" for more
information.)
Use the -offline option separately for each connection context offline checker you
want to specify; these settings have no influence on each other. For example:
-offline@CtxClass2=oracle.sqlj.checker.Oracle8OfflineChecker
-offline@CtxClass3=sqlj.semantics.OfflineChecker
To specify the offline checker for the default connection context and any other
connection contexts for which you do not specify an offline checker:
-offline=oracle.sqlj.checker.Oracle8OfflineChecker
Any connection context without an offline checker setting uses the offline checker
setting of the default connection context, presuming an offline checker has been set for
the default context.
The command-line syntax for this option is as follow:
-offline<@conn_context_class>=checker_class
For example:
-offline=oracle.sqlj.checker.Oracle8OfflineChecker
-offline@CtxClass=oracle.sqlj.checker.Oracle8OfflineChecker
sqlj.offline<@conn_context_class>=checker_class
For example:
sqlj.offline=oracle.sqlj.checker.Oracle8OfflineChecker
sqlj.offline@CtxClass=oracle.sqlj.checker.Oracle8OfflineChecker
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oracle.sqlj.checker.OracleChecker
Online Semantics-Checker (-online)

The -online option specifies a Java class or list of classes that implement the online
semantics-checking component of SQLJ. This involves connecting to a database. Note
that online checking is not enabled by the -online option. You must enable it through
the -user option. The -password, -url, and -driver options must be set appropriately
as well.
Note:
Some settings of the SQLJ -parse option will disable online semantics-
checking, overriding the effect of the -user option.
You can specify different online checkers for different connection contexts, and you
can list multiple checkers (separated by commas) for any given context. In cases
where multiple checkers are listed for a single context, SQLJ uses the first checker
(reading from left to right in the list) that accepts the database connection established
for online checking. At analysis time, a connection is passed to each online checker
and the checker decides whether it recognizes the database.
The default OracleChecker, a front-end class, will serve your needs unless you want to
specify a particular checker that would not be chosen by OracleChecker.
The following example shows how to select Oracle8 online checker for the
DefaultContext class and any other connection context classes without a specified
setting:
->
To specify a list of drivers and allow the proper class to be selected depending on what
kind of database is being accessed:
->
With this specification, if connection is made to Oracle Database, then

SQLJ uses the oracle.sqlj.checker.Oracle8JdbcChecker semantics-checker. If
connection is made to any other kind of database, then SQLJ uses the generic
sqlj.semantics.JdbcChecker semantics-checker. This is similar functionally to what
the default OracleChecker.
To specify the online checker for a particular connection context (CtxClass):

-online@CtxClass=oracle.sqlj.checker.Oracle8JdbcChecker
This results in the use of oracle.sqlj.checker.Oracle8JdbcChecker for online

checking of any of your SQLJ executable statements that specify a connection object
that is an instance of CtxClass, presuming you enable online checking for CtxClass.
The CtxClass connection context class must be declared in your source code or
previously compiled into a .class file.
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Use the -online option separately for each connection context online checker you
want to specify. These settings have no influence on each other:
-online@CtxClass2=oracle.sqlj.checker.Oracle8JdbcChecker
-online@CtxClass3=sqlj.semantics.JdbcChecker
Any connection context without an online checker setting uses the online checker
setting of the default connection context.
-online<@conn_context_class>=checker_class(list)
For example:
- >- >-online@CtxClass=oracle.sqlj.checker.Oracle8JdbcChecker
sqlj.online<@conn_context_class>=checker_class(list)
For example:
sqlj. >sqlj. >sqlj.online@CtxClass=oracle.sqlj.checker.Oracle8JdbcChecker

Caching of Online Semantics-Checker Results (-cache)

Use the -cache option to enable caching of the results generated by the online
checker. This avoids additional database connections during subsequent SQLJ
translation runs. The analysis results are cached in a file, SQLChecker.cache, that
is placed in your current directory. The cache contains serialized representations
of all SQL statements successfully translated (translated without error or warning
messages), including all statement parameters, return types, translator settings, and
modes.
The cache is cumulative and continues to grow through successive invocations of the
SQLJ translator. Delete the SQLChecker.cache file to empty the cache.

-cache<=true|false>
For example:
-cache
sqlj.cache<=true|false>
For example:
sqlj.cache
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false
Offline Parser (-parse)

Use the -parse option to enable offline parsing. This feature is a complement to online
semantics-checking, offering SQL and PL/SQL syntax-checking (but not verification
against the schema) without a database connection during translation. Offline parsing
also checks syntax for DDL statements, which online checking does not.
Also be aware that the setting of the -parse option can override the enabling of online
checking by the -user option. Possible -parse settings are as follows:
• both (default): Enable the offline parser and allow online checking. In this case,
online checking is determined by the -user option.
• online-only: Disable the offline parser and allow online checking. Again, online
checking is determined by the -user option.
• offline-only: Enable the offline parser and disallow online checking. This
overrides any -user option setting that would otherwise enable online checking.
• none: Disable the offline parser and disallow online checking, Again, this overrides
any -user option setting that would otherwise enable online checking.
• parserclassname: Specify the name of a Java class that implements
an alternative SQL parser. The class must implement the
sqlj.framework.checker.SimpleChecker interface. This setting enables the
specified parser, and only that parser is used for SQL-checking. The standard
offline parser and online checking are both disabled.
FUTURE: Document the SimpleChecker interface.
The offline-only and none settings are offered for completeness, but are not typical
modes of operation. It is best to let the -user option determine online checking. It is
also not typical to specify your own parser.
Note:
In modes where both offline parsing and online checking are enabled, there
may be duplicate reporting of some problems.

-parse=both|online-only|offline-only|none|parserclassname
For example:
-parse=online-only
sqlj.parse=both|online-only|offline-only|none|parserclassname
For example:
sqlj.parse=online-only
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Translator Support and Options for Alternative Environments

both
9.4 Translator Support and Options for Alternative

Environments
By default, the Oracle Database 12c Release 1 (12.1) SQLJ implementation is
configured to run under standard JDK 6 and to use the standard compiler javac.
These are not requirements, however. You can configure SQLJ to work with alternative
JVMs or compilers. To do so, you must supply SQLJ with the following information:
• The name of the JVM to use (-vm option)
• The name of the Java compiler to use (-compiler-executable option)
• Any settings the compiler requires
A set of SQLJ options enables you to provide this information. SQLJ also defaults to
Oracle profile customizer, but can work with alternative customizers as well.
Note:
Be aware of the limitations of any operating system and environment you
use. In particular, the complete, expanded SQLJ command line must not
exceed the maximum command-line size. Consult your operating system
documentation.

• Java and Compiler Options
• Customization Options
9.4.1 Java and Compiler Options

The following options relate to the operation of the JVM and Java compiler:
• -vm (to specify the JVM, on the command line only)
• -compiler-executable (to specify the Java compiler)
• -compiler-encoding-flag
• -compiler-output-file
• -compiler-pipe-output-flag
Some compilers, such as the standard javac, require a Java source file name to
match the name of the public class, if any, defined there. Therefore, by default the
SQLJ translator verifies that this is true. However, you can use the -checkfilename
option to instruct SQLJ not to verify this.
For some JVM and compiler configurations, there may be problems with the way
SQLJ usually invokes the compiler. You can use the -passes option to alleviate this by
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breaking SQLJ processing into a two-pass process. You can also pass options directly
to the particular JVM or compiler you use, through the -J and -C prefixes.
Note:
The -vm option, -passes option, and -J prefix cannot be used in a properties
file. You can set them on the command line or, more conveniently, in the
SQLJ_OPTIONS environment variable.
Name of the Java Virtual Machine (-vm)

Use the -vm option if you want to specify a particular JVM for SQLJ to use. Otherwise,
SQLJ uses the standard java from the Sun Microsystems JDK. You cannot set this
option in a properties file, because properties files are read after the JVM is invoked.
If you do not specify a directory path along with the name of the JVM executable file,
then SQLJ looks for the executable according to the setting of your operating system
PATH variable.
Note:
Special functionality of this option, -vm=echo, is supported. This is equivalent
to the -n option, instructing the sqlj script to construct the full command line
that would be passed to the SQLJ translator, and echo it to the user without
having the translator execute it.

-vm=JVM_path+name
For example:
-vm=/myjavadir/myjavavm

java
Name of the Java Compiler (-compiler-executable)

Use the -compiler-executable option if you want to specify a particular Java
compiler for SQLJ to use. Otherwise SQLJ, uses the standard javac from the Sun
Microsystems JDK.
If you do not specify a directory path along with the name of the compiler executable
file, then SQLJ looks for the executable according to the setting of your operating
system PATH variable.
The following is required of any Java compiler that you use:

• It can write error and status information to the standard output device (for
example, STDOUT on a UNIX system) or to a file, as directed by the -compiler-
output-file option.
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• It will understand the SQLJ -d option, which determines the root directory for class
files.
• It must return a nonzero exit code to the operating system whenever a compilation
error occurs.
• The line information that it provides in any errors or messages must be in one of
the following formats (items in <> brackets being optional):
– Sun Microsystems javac format
filename.java:line<.column><-line<.column>>
Example: myfile.java:15: Illegal character: '\u01234'

– Microsoft jvc format
filename.java(line,column)
Example: myfile.java(15,7) Illegal character: '\u01234'

As always, SQLJ processes compiler line information so that it refers to line numbers
in the original .sqlj file, not in the produced .java file.
Note:
For a compiler that does not support an -encoding option, disable the
-compiler-encoding-flag.

-compiler-executable=Java_compiler_path+name
For example:
-compiler-executable=/myjavadir/myjavac
sqlj.compiler-executable=Java_compiler_path+name
For example:
sqlj.compiler-executable=myjavac

javac
Compiler Encoding Support (-compiler-encoding-flag)

When you use the -encoding option to specify an encoding character set for SQLJ
to use, SQLJ passes this to the Java compiler for the compiler to use as well. Set
the -compiler-encoding-flag to false if you do not want SQLJ to pass the character
encoding to the compiler. For example, if you are using a compiler other than javac
and it does not support an -encoding option by that name.
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-compiler-encoding-flag<=true|false>
For example:
-compiler-encoding-flag=false
sqlj.compiler-encoding-flag<=true|false>
For example:
sqlj.compiler-encoding-flag=false

true
Compiler Output File (-compiler-output-file)

If you want the Java compiler to write its results to a file, then use the -compiler-
output-file option to make SQLJ aware of the file name. Otherwise, SQLJ assumes
that the compiler writes to the standard output device, such as STDOUT on a UNIX
system. As appropriate, specify an absolute path or a relative path from the current
directory.
Note:
You cannot use this option if you enable -passes, which requires output to
STDOUT.

-compiler-output-file=output_file_path+name
For example:
-compiler-output-file=/myjavadir/mycmploutput
sqlj.compiler-output-file=output_file_path+name
For example:
sqlj.compiler-output-file=/myjavadir/mycmploutput
This option does not have a default value.
Compiler Message Output Pipe (-compiler-pipe-output-flag)
Note:
This option is relevant only for JDK 1.2.x.
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By default, the Java compiler writes errors and message output to STDERR. However,
if the error messages from the Java compiler should also be redirected to the same
file as specified with the -compiler-output-file option, then set this flag to true.
This option is meaningful only if used in conjunction with the -compiler-output-file
option.
If SQLJ sets the javac.pipe.output system property to true, which is the SQLJ
default behavior when it invokes the Java compiler, then compiler error and message
output will be sent to STDOUT. However, you can specify -compiler-pipe-output-
flag=false to instruct SQLJ to not set this system property when it invokes the Java
compiler. You should do this, for example, if the Java compiler you are using does not
support the javac.pipe.output system property.
You can set this flag in a properties file, as well as on the command line or in the
SQLJ_OPTIONS environment variable.
Note:
For a Java compiler that originates from Sun Microsystems and writes its
output to STDERR by default, you must leave -compiler-pipe-output-flag
enabled, if you enable -passes, which requires output to STDOUT.

-compiler-pipe-outflag=<true|false>
For example, while compiling a file called MyDemo.sqlj, for which the Java compiler
messages and error messages are to be redirected to the same file, the following
syntax should be used:
sqlj -compiler-output-file=/myjavadir/mycmploutput
-compiler-pipe-output-flag=true MyDemo.sqlj
sqlj.compiler-pipe-output-flag<=true|false>

true
Note:
If this flag is set to false, then the error messages from the Java compiler will
be directed to STDERR.
Source File Name Check (-checkfilename)

It is generally advisable for the source file name to always match the name of the
public class defined or, if there is no public class, the name of the first class defined.
For example, public class MyPublicClass should be defined in a MyPublicClass.sqlj
source file.
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The -checkfilename flag instructs SQLJ whether to verify that the SQLJ source file
name matches the name of the public class, if any, defined there. Some compilers,
such as the standard javac, require this to be the case, while others do not.
To maximize portability of your code, this flag should be enabled, which it is by default.
Note:
If you are translating in the server, where there is no equivalent naming
requirement, there is no -checkfilename option and the translator executes
no such check.

-checkfilename<=true|false>
For example:
-checkfilename=false
sqlj.checkfilename<=true|false>
For example:
sqlj.checkfilename=false

true
SQLJ Two-Pass Execution (-passes)

By default, the following occurs when you invoke the sqlj script:
1. The sqlj script invokes your JVM, which runs the SQLJ translator.
2. The translator completes the semantics-checking and translation of your .sqlj
files, generating translated .java files.
3. The translator invokes your Java compiler, which compiles the generated .java
files.
4. The translator processes the compiler output.
5. If any profile files were generated, then the translator invokes a profile customizer
to customize them.
For some JVM and compiler configurations, however, the compiler invocation in Step 3
might not return, in which case your translation will suspend.
If you encounter this situation, the solution is to instruct SQLJ to run in two passes,
with the compilation step in between. To accomplish this, you must enable the two-
pass execution flag as follows:
-passes
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The -passes option must be specified on the command line or, equivalently, in the
SQLJ_OPTIONS environment variable. It cannot be specified in a properties file.
Note:
• If you enable -passes, then compiler output must go to STDOUT.

Therefore, leave -compiler-pipe-output-flag enabled, which is its
default. In addition, you cannot use the -compiler-output-file option,
which would result in writing to a file instead of to STDOUT.
• Like other command-line-only flags (-help, -version, -n), the -passes
flag does not support =true syntax.
With -passes enabled, the following occurs when you invoke the sqlj script:
1. The sqlj script invokes your JVM, which runs the SQLJ translator for its first pass.
2. The translator completes the semantics-checking and translation of your .sqlj
files, generating translated .java files.
3. The JVM is terminated.
4. The sqlj script invokes the Java compiler, which compiles the generated .java
files.
5. The sqlj script invokes your JVM again, which runs the SQLJ translator for its
second pass.
6. The translator processes compiler output.
7. If any profile files were generated, the JVM runs your profile customizer to
customize them.
With this sequence, you circumvent any problems the JVM might have in invoking the
Java compiler.
-passes
For example:
-passes

off
9.4.2 Customization Options

The following options relate to the customization of your SQLJ profiles, if applicable:
• -default-customizer
• Options passed directly to the customizer
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Note:
If you use the default Oracle-specific code generation, then SQLJ generates
no profiles and, therefore, performs no customization. In that case, these
options do not apply.
Default Profile Customizer (-default-customizer)

Use the -default-customizer option to instruct SQLJ to use a profile customizer
other than the default, which is:
oracle.sqlj.runtime.util.OraCustomizer
In particular, use this option if you are not using Oracle Database. This option takes a
fully qualified Java class name as its argument.
Note:
You can override this option with the -P-customizer option in your SQLJ
command line or properties file.

-default-customizer=customizer_classname
For example:
-default-customizer=sqlj.myutil.MyCustomizer
sqlj.default-customizer=customizer_classname
For example:
sqlj.default-customizer=sqlj.myutil.MyCustomizer

Note:
When you use Oracle Database and ISO code generation, Oracle
recommends that you use the default OraCustomizer for your profile
customization.
Options Passed Directly to the Customizer

As with the JVM and compiler, you can pass options directly to the profile customizer
harness using a prefix, in this case -P.
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Translator and Run-Time Functionality
This chapter discusses internal operations and functionality of Oracle SQLJ translator
and run time.
The following topics are covered:
• Internal Translator Operations
• Functionality of Translator Errors_ Messages_ and Exit Codes
• SQLJ Run Time
• Globalization Support in the Translator and Run Time
10.1 Internal Translator Operations

The following topics summarize the operations executed by the SQLJ translator during
a translation:
• Java and SQLJ Code-Parsing and Syntax-Checking
• SQL Semantics-Checking and Offline Parsing
• Code Generation
• Java Compilation
• Profile Customization (ISO Code Generation)
10.1.1 Java and SQLJ Code-Parsing and Syntax-Checking

In this first phase of SQLJ translation, a SQLJ parser and a Java parser are used
to process all the source code and check syntax. As the SQLJ translator parses
the .sqlj file, it invokes a Java parser to check the syntax of Java statements and a
SQLJ parser to check the syntax of SQLJ constructs (anything preceded by #sql). The
SQLJ parser also invokes the Java parser to check the syntax of Java host variables
and expressions within SQLJ executable statements.
The SQLJ parser checks the grammar of SQLJ constructs according to the SQLJ
language specification. However, it does not check the grammar of the embedded
SQL operations. SQL syntax is not checked until the semantics-checking or offline
parsing step.
This syntax-check will look for errors like missing semi-colons, mismatched curly
braces, and obvious type mismatches, such as multiplying a number by a string. If
the parsers find any syntax errors or type mismatches during this phase, then the
translation is aborted and the errors are reported to the user.
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Internal Translator Operations
10.1.2 SQL Semantics-Checking and Offline Parsing

Once the SQLJ and Java application source code is verified as syntactically correct,
the translator enters into the semantics-checking phase and invokes a SQL semantics-
checker or a SQL offline parser or both, according to SQLJ option settings.
Setting the -user option enables online checking, and setting the -password and
-url options specifies the database connection, if the password and URL were not
specified in the -user option. The -offline or -online option specifies which checker
to use. The default, typically sufficient, is a checker front end called OracleChecker
that chooses the most appropriate checker, according to whether you have enabled
online checking and which Java Database Connectivity (JDBC) driver you are using.
The -parse option, true by default, is for enabling the offline parser, which offers
a way to verify SQL and PL/SQL syntax (but not data types against database
columns) without necessitating a database connection during translation. Note that
some settings of the -parse option will override the -user option and disable online
checking.
See Also:
"Connection Options" and "Semantics-Checking and Offline-Parsing Options"
Note:
For ISO code generation, semantics-checking can also be performed on a
profile that was produced during a previous execution of the SQLJ translator.
Refer to "SQLCheckerCustomizer for Profile Semantics-Checking".
The following tasks are always performed during semantics-checking, regardless of

the status of online checking or offline parsing:
1. SQLJ analyzes the types of Java expressions in your SQLJ executable
statements.
This includes examining the SQLJ source files being translated, any .java files
entered on the command line, and any imported Java classes whose .class files
or .java files can be found through the classpath. SQLJ examines whether and
how stream types are used in SELECT or CAST statements, what Java types are
used in iterator columns or INTO-lists, what Java types are used as input host
variables, and what Java types are used as output host variables.
SQLJ also processes FETCH, CAST, CALL, SET TRANSACTION, VALUES, and SET
statements syntactically.
Any Java expression in a SQLJ executable statement must have a Java type valid
for the given situation and usage. For example, consider the following statement:
#sql [myCtx] { UPDATE ... };
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The myCtx variable, which might be used to specify a connection context instance
or execution context instance for this statement, must actually resolve to a SQLJ
connection context type or execution context type.
Now consider the following example:
#sql { UPDATE employees SET salary = :newSal };
If newSal is a variable, as opposed to a field, then an error is generated if newSal

was not previously declared. In any case, an error is generated if it cannot be
assigned to a valid Java type or its Java type cannot be used in a SQL statement
(for example, java.util.Vector).
Note:
Semantics-checking of Java types is performed only for Java
expressions within SQLJ executable statements. Such errors in your
standard Java statements will not be detected until compilation by the
Java compiler.
2. SQLJ tries to categorize your embedded SQL operations. Each operation must
have a recognizable keyword, such as SELECT or INSERT, so that SQLJ knows
what kind of operation it is. For example, the following statement will generate an
error:
#sql { foo };
3. If either online checking or offline parsing (or both) is enabled, then SQLJ analyzes
and verifies the syntax of embedded SQL and PL/SQL operations.
4. If either online checking or offline parsing (or both) is enabled, then SQLJ checks
the types of Java expressions in SQLJ executable statements against SQL types
of corresponding columns in the database and SQL types of corresponding
arguments and return variables of stored procedures and functions.
In the process of doing this, SQLJ verifies that the SQL entities used in your SQLJ
executable statements, such as tables, views, and stored procedures, actually
exist in the database. SQLJ also checks nullability of database columns whose
data is being selected into iterator columns of Java primitive types, which cannot
process null data. However, nullability is not checked for stored procedure and
function output parameters and return values.
10.1.3 Code Generation

For the .sqlj application source file, the SQLJ translator generates a .java file and,
for ISO standard SQLJ code generation, at least one profile (either in .ser or .class
files). The .java contains your translated application source code, class definitions
for any private iterators and connection contexts you declared, and, for ISO code, a
profile-keys class definition generated and used internally by SQLJ.
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Note:
No profiles or profile-keys class are generated if you use the default Oracle-
specific code generation mode.
With ISO code generation, there are no profiles or profile-keys class if you do
not use any SQLJ executable statements in your code.
Generated Application Code in .java File

For the default Oracle-specific code generation, the generated .java file for your
application contains direct calls to Oracle JDBC driver in place of the original SQLJ
executable statements. There are also calls to an Oracle-specific SQLJ run time. For
ISO standard SQLJ code generation, SQLJ executable statements are replaced by
calls to the SQLJ run time, which in turn contains calls to the JDBC driver.
For convenience, generated .java files also include a comment for each of your #sql
statements, repeating the statement in its entirety for reference. The generated .java
file will have the same base name as the input .sqlj file, which would be the name of
the public class defined in the .sqlj file or the first class defined if there are no public
classes. For example, Foo.sqlj defines the Foo class. The Foo.java source file will be
generated by the translator.
The location of the generated .java file depends on whether and how you set the
SQLJ -dir option. By default, the .java file will be placed in the directory of the .sqlj
input file.
See Also:
"Output Directory for Generated .java Files (-dir)"
Generated Profile-Keys Class in .java File (ISO Code Generation)

If you use ISO standard SQLJ code generation, SQLJ generates a profile-keys class
that it uses internally during run time to load and access the serialized profile. This
class contains mapping information between the SQLJ run time calls in your translated
application and the SQL operations placed in the serialized profile. It also contains
methods to access the serialized profile.
Note:
If you use the default Oracle-specific code generation, no profiles or profile-
keys classes are generated.
The profile-keys class is defined in the same .java output file that has your translated
application source code, with a class name based on the base name of your .sqlj
source file as follows:
Basename_SJProfileKeys
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For example, translating Foo.sqlj defines the following profile-keys class in the
generated .java file:
Foo_SJProfileKeys
If your application is in a package, this is reflected appropriately. For example,

translating Foo.sqlj in the a.b package defines the following class:
a.b.Foo_SJProfileKeys
Generated Profiles in .ser or .class Files (ISO Code Generation)

If you use ISO standard SQLJ code generation, SQLJ generates profiles that it
uses to store information about the SQL operations found in the input file. A profile
is generated for each connection context class that you use in your application. It
describes the operations to be performed using instances of the associated connection
context class, such as SQL operations to execute, tables to access, and stored
procedures and functions to call.
Note:
If you use the default Oracle-specific code generation, then information about
the SQL operations is embedded in the generated code, which calls Oracle
JDBC driver directly. In this case, SQLJ does not generate profiles.
Profiles are generated in .ser serialized resource files. However, if you enable the
SQLJ -ser2class option, then the profiles are automatically converted to .class
files as part of the translation. In this case, no further customization of the profile
is possible. You would have to delete the .class file and rerun the SQLJ translator to
regenerate the profile.
Profile base names are generated similarly to the profile-keys class name. They are
fully qualified with the package name, followed by the .sqlj file base name, followed
by the string:
_SJProfilen
Where n is a unique number, starting with 0, for each profile generated for a
particular .sqlj input file.
Again using the example of the Foo.sqlj input file, if two profiles are generated, then
they will have the following base names (presuming no package):
Foo_SJProfile0
Foo_SJProfile1
If Foo.sqlj is in the a.b package, then the profile base names will be:
a.b.Foo_SJProfile0
a.b.Foo_SJProfile1
Physically, a profile exists as a Java serialized object contained within a resource file.
Resource files containing profiles use the .ser extension and are named according to
the base name of the profile (excluding package names). Resource files for the two
previously mentioned profiles will be named as follows:
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Foo_SJProfile0.ser
Foo_SJProfile1.ser
Or, they will be named Foo_SJProfile0.class and Foo_SJProfile1.class if you

enable the -ser2class option. If you choose this option, then the conversion to .class
takes place after the customization step.
See Also:
"Conversion of .ser File to .class File (-ser2class)"
The location of these files depends on how the SQLJ -d option is set, which
determines where all generated .ser and .class files are placed.
See Also:
"Output Directory for Generated .ser and .class Files (-d)"
More About Generated Calls to SQLJ Run Time

When #sql statements are replaced by calls to the JDBC driver (for Oracle-specific
code generation) or to the SQLJ run time (for ISO standard SQLJ code generation),
these calls implement the steps in Table 10-1.
Table 10-1 Steps for Generated Calls, ISO Standard Versus Oracle-Specific
Steps for ISO Standard Code Generation Steps for Oracle Code Generation
Get a SQLJ statement object, using Get an Oracle JDBC statement object.
information stored in the associated profile
entry.
Bind inputs into the statement, using Bind inputs using Oracle JDBC statement
setXXX() methods of the statement object. methods and, if necessary, register output
parameters.
Execute the statement, using the Execute the Oracle statement.
executeUpdate() or executeQuery()
method of the statement object.
Create iterator instances, if applicable. Create iterator instances, if applicable.
Retrieve outputs from the statement, using Retrieve outputs from the statement using
getXXX() methods of the statement object. appropriate JDBC getter methods.
Close the SQLJ statement object (by default, Close the JDBC statement object (by default,
recycling it through the SQLJ statement recycling it through the JDBC statement
cache). cache).
A SQLJ run time uses SQLJ statement objects that are similar to JDBC statement
objects, although a particular implementation of SQLJ might or might not use JDBC
statement classes directly. SQLJ statement classes add functionality particular to
SQLJ. For example:
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• Standard SQLJ statement objects raise a SQL exception if a null value from the
database is to be output to a primitive Java type, such as int or float, which
cannot take null values.
• Oracle SQLJ statement objects allow user-defined object and collection types to
be passed to or retrieved from Oracle Database.
10.1.4 Java Compilation

After code generation, SQLJ invokes the Java compiler to compile the
generated .java file. This produces a .class file for each class you defined in your
application, including iterator and connection context declarations, as well as a .class
file for the generated profile-keys class if you use ISO code generation (and presuming
your application uses SQLJ executable statements). Any .java files you specified
directly on the SQLJ command line (for type-resolution, for example) are compiled at
this time as well.
In the example used in "Code Generation", the following .class files would be
produced in the appropriate directory (given package information in the source code):
• Foo.class
• Foo_SJProfileKeys.class (ISO code generation only)
• A .class file for each additional class you defined in Foo.sqlj
• A .class file for each iterator and connection context class you declared in
Foo.sqlj (whether public or private)
To ensure that .class files and profiles (if any, whether .ser or .class) will be located
in the same directory, SQLJ passes its -d option to the Java compiler. If the -d option
is not set, then .class files and profiles are placed in the same directory as the
generated .java file, which is placed according to the -dir option setting.
In addition, so that SQLJ and the Java compiler will use the same encoding,
SQLJ passes its -encoding option to the Java compiler unless the SQLJ -compiler-
encoding-flag is turned off. If the -encoding option is not set, then SQLJ and
the compiler will use the setting in the Java virtual machine (JVM) file.encoding
property.
By default, SQLJ invokes the standard javac compiler of the Sun Microsystems Java
Development Kit (JDK), but other compilers can be used instead. You can request
that an alternative Java compiler be used by setting the SQLJ -compiler-executable
option.
Note:
If you are using the SQLJ -encoding option but using a compiler that does
not have an -encoding option, then turn off the SQLJ -compiler-encoding-
flag. Otherwise, SQLJ will attempt to pass the -encoding option to the
compiler.
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10.1.5 Profile Customization (ISO Code Generation)

After Java compilation, if you are using ISO standard code generation, then the
generated profiles containing information about your embedded SQL instructions are
customized, so that your application can work efficiently with your database and use
vendor-specific extensions.
Note:
If you use the default Oracle-specific code generation, then SQLJ produces
no profiles and skips the customization step. Your code will support
Oracle-specific features through direct calls to Oracle JDBC application
programming interfaces (APIs).
If you want to check for the options already set on the customizer, then you can make
use of the following command:
% sqlj -P-print *.ser
For more information about profile print option, refer to "Specialized Customizer:
Profile Print Option (print)".
To accomplish customization, SQLJ invokes a front end called the customizer harness,
which is a Java class that functions as a command-line utility. The harness, in turn,
invokes a particular customizer, either the default Oracle customizer or a customizer
that you specify through SQLJ option settings.
During customization, profiles are updated in the following ways:
• To enable your application to use any vendor-specific database types or features,
if applicable
• To tailor the profiles so that your application is as efficient as possible in using
features of the relevant database environment
Without customization, you can access and use only standard JDBC types.
For example, Oracle customizer can update a profile to support a SQL PERSON type
that you had defined. You could then use PERSON as you would any other supported
data type.
You must also customize with Oracle customizer to use any of the oracle.sql type
extensions.
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Functionality of Translator Errors, Messages, and Exit Codes
Note:
Be aware of the following regarding profile customization:
• Oracle SQLJ run time and an Oracle JDBC driver will be required by
your application whenever you use Oracle customizer during translation,
even if you do not use Oracle extensions in your code.
• The generic SQLJ run time will be used if your application has no
customizations, or none suitable for the connection.
• You can customize previously created profiles by specifying .ser files,
or .jar files containing .ser files, on the command line. But you cannot
do this in the same running of SQLJ where translations are taking place.
You can specify .ser/.jar files to be customized or .sqlj/.java files to
be translated, compiled, and customized, but not both categories. For
more information about how .jar files are used, refer to "JAR Files for
Profiles".
10.2 Functionality of Translator Errors, Messages, and Exit

Codes
This section provides an overview of SQLJ translator messages and exit codes. It
covers the following topics:
• Translator Error_ Warning_ and Information Messages
• Translator Status Messages
• Translator Exit Codes
10.2.1 Translator Error, Warning, and Information Messages

There are three major levels of SQLJ messages that you may encounter during the
translation phase: error, warning, and information. Warning messages can be further
broken down into two levels: nonsuppressible and suppressible. Therefore, there are
four message categories (in order of seriousness):
1. Errors
2. Nonsuppressible warnings
3. Suppressible warnings
4. Information
You can control suppressible warnings and information by using the SQLJ -warn
option.
Error messages, prefixed by Error:, indicate that one of the following has been
encountered:
• A condition that would prevent compilation (for example, the source file contains a
public class whose name does not match the base file name)
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• A condition that would result in a run-time error if the code were executed (for
example, the code attempts to fetch a VARCHAR into a java.util.Vector, using an
Oracle JDBC driver)
If errors are encountered during SQLJ translation, then no output is produced and
compilation and customization are not executed.
Nonsuppressible warning messages, prefixed by Warning:, indicate that one of the
following has been encountered:
• A condition that would probably, but not necessarily, result in a run-time error if
the code were executed (for example, a SELECT statement whose output is not
assigned to anything)
• A condition that compromises the ability of SQLJ to verify run-time aspects of your
source code (for example, not being able to connect to the database you specify
for online checking)
• A condition that presumably resulted from a coding error or oversight
SQLJ translation will complete if a nonsuppressible warning is encountered, but you
should analyze the problem and determine if it should be fixed before running the
application. If online checking is specified but cannot be completed, then offline
checking is performed instead.
Note:
For logistical reasons, the parser that the SQLJ translator uses to analyze
SQL operations is not the same top-level SQL parser that will be used at run
time. Therefore, errors might occasionally be detected during translation that
will not actually cause problems when your application runs. Accordingly,
such errors are reported as nonsuppressible warnings, rather than fatal
errors.
Suppressible warning messages, also prefixed by Warning:, indicate that there is a

problem with a particular aspect of your application, such as portability. An example of
this is using an Oracle-specific type, such as oracle.sql.NUMBER, to read from or write
to Oracle Database 12c Release 1 (12.1).
Informational or status messages prefixed by Info: do not indicate an error condition.
They merely provide additional information about what occurred during the translation
phase.
Suppressible warning and status messages can be suppressed by using the various
-warn option flags:
• cast/nocast: The nocast setting suppresses warnings about possible run-time

errors when trying to cast an object type instance to an instance of a subtype.
• precision/noprecision: The noprecision setting suppresses warnings regarding
possible loss of data precision during conversion.
• nulls/nonulls: The nonulls setting suppresses warnings about possible run-time
errors due to nullable columns or types.
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• portable/noportable: The noportable setting suppresses warnings regarding

SQLJ code that uses Oracle-specific features or might otherwise be nonstandard
and, therefore, not portable to other environments.
• strict/nostrict: The nostrict setting suppresses warnings issued if there are
fewer columns in a named iterator than in the selected data that is to populate the
iterator.
• verbose/noverbose: The noverbose setting suppresses status messages that are
merely informational and do not indicate error or warning conditions.
If you receive warnings during your SQLJ translation, then you can try running the
translator again with -warn=none to see if any of the warnings are of the more serious
(nonsuppressible) variety.
The following table summarizes the categories of error and status messages
generated by the SQLJ translator.
Table 10-2 SQLJ Translator Error Message Categories
Message Category Prefix Indicates Suppressed By

Error Error: Fatal error that will cause NA
compilation failure or run-time
failure (translation aborted)
Nonsuppressible Warning: Condition that prevents proper NA
warning translation or might cause
run-time failure (translation
completed)
Suppressible warning Warning: Problem regarding a particular -warn option
aspect of your application flags: nocast
(translation completed) noprecision
nonulls
noportable
nostrict
Informational/status Info: Information regarding the -warn option flag:
message translation process noverbose
10.2.2 Translator Status Messages

In addition to the error, warning, and information messages, SQLJ can produce status
messages throughout all phases of SQLJ operation: translation, compilation, and
customization. Status messages are produced as each file is processed and at each
phase of SQLJ operation.
You can control status messages by using the SQLJ -status option.
See Also:
"Real-Time Status Messages (-status)"
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SQLJ Run Time
10.2.3 Translator Exit Codes

The following exit codes are returned by the SQLJ translator to the operating system
upon completion:
• 0: No error in execution
• 1: Error in SQLJ execution
• 2: Error in Java compilation
• 3: Error in profile customization
• 4: Error in class instrumentation, the optional mapping of line numbers from
your .sqlj source file to the resulting .class file
• 5: Error in ser2class conversion, the optional conversion of profile files from .ser
files to .class files
Note:
• If you issue the -help or -version option, then the SQLJ exit code is 0.
• If you run SQLJ without specifying any files to process, then SQLJ
issues help output and returns exit code 1.
10.3 SQLJ Run Time

This section presents information about Oracle SQLJ run time, which is a thin layer of
pure Java code that runs above the JDBC driver.
If you use the default Oracle-specific code generation, then the SQLJ run-time layer
becomes even thinner, with a run time subset being used in conjunction with an Oracle
JDBC driver. Most of the run-time functionality is compiled directly into Oracle JDBC
calls. You cannot use a non-Oracle JDBC driver.
See Also:
When SQLJ translates SQLJ source code using ISO standard code generation,
embedded SQL commands in your Java application are replaced by calls to the SQLJ
run time. Run-time classes act as wrappers for equivalent JDBC classes, providing
special SQLJ functionality. When the end user runs the application, the SQLJ run time
acts as an intermediary, reading information about your SQL operations from your
profile and passing instructions along to the JDBC driver.
Generally speaking, however, a SQLJ run time can be implemented to use any
JDBC driver or vendor-proprietary means of accessing the database. Oracle SQLJ
run time requires a JDBC driver, but can use any standard JDBC driver. To use
Oracle-specific data types and features, however, you must use an Oracle JDBC
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SQLJ Run Time
driver. For the purposes of this document, it is generally assumed that you are using
Oracle Database and one of Oracle JDBC drivers.
Note:
For ISO standard SQLJ code generation, Oracle SQLJ run time and an
Oracle JDBC driver will be required by your application whenever you
use Oracle customizer during translation, even if you do not use Oracle
extensions in your code. The generic SQLJ run time will be used if your
application has no customizations, or none suitable for the connection.
10.3.1 SQLJ Run Time Packages

Oracle SQLJ run time includes packages you will likely import and use directly, and
others that are used only indirectly.
Note:
These packages are included in the run-time libraries runtime12,
runtime12ee, and runtime.
Packages Used Directly

The packages containing classes that you can import and use directly in your
application are:
• sqlj.runtime
This package includes the ExecutionContext class, ConnectionContext
interface, ConnectionContextFactory interface, ResultSetIterator interface,
ScrollableResultSetIterator interface, and wrapper classes for streams
(BinaryStream and CharacterStream, as well as the deprecated AsciiStream and
UnicodeStream).
Interfaces and abstract classes in this package are implemented by classes in the
sqlj.runtime.ref or oracle.sqlj.runtime package or by classes generated by
the SQLJ translator.
• sqlj.runtime.ref
The classes in this package implement interfaces and abstract classes in the
sqlj.runtime package. You will likely use the sqlj.runtime.ref.DefaultContext
class, which is used to specify your default connection and create default
connection context instances. The other classes in this package are used
internally by SQLJ in defining classes during code generation, such as iterator
classes and connection context classes that you declare in your SQLJ code.
• oracle.sqlj.runtime
This package contains the Oracle class that you can use to instantiate the
DefaultContext class and establish your default connection. It also contains
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SQLJ Run Time
Oracle-specific run-time classes used by the Oracle implementation of SQLJ,

including functionality to convert to and from Oracle type extensions.
Note:
Packages whose names begin with oracle are for Oracle-specific SQLJ
features.
Packages Used Indirectly

The packages containing classes that are for internal use by SQLJ are:
• sqlj.runtime.profile
This package contains interfaces and abstract classes that define what SQLJ
profiles look like (applicable only for ISO standard code generation). This includes
the EntryInfo and TypeInfo classes. Each entry in a profile is described by an
EntryInfo object, where a profile entry corresponds to a SQL operation in your
application. Each parameter in a profile entry is described by a TypeInfo object.
The interfaces and classes in this package are implemented by classes in the
sqlj.runtime.profile.ref package.
• sqlj.runtime.profile.ref
This package contains classes that implement the interfaces and abstract classes
of the sqlj.runtime.profile package and are used internally by the SQLJ
translator in defining profiles (for ISO standard code generation only). It also
provides the default JDBC-based run-time implementation.
• sqlj.runtime.error
This package, used internally by SQLJ, contains resource files for all generic (not
Oracle-specific) error messages that can be generated by the SQLJ translator.
• oracle.sqlj.runtime.error
This package, used internally by SQLJ, contains resource files for all Oracle-
specific error messages that can be generated by the SQLJ translator.
10.3.2 Categories of Run-Time Errors

Run-time errors can be generated by any of the following:
• SQLJ run time
• JDBC driver
• RDBMS
In any of these cases, a SQL exception is generated as an
instance of the java.sql.SQLException class, or as a subclass, such as
sqlj.runtime.SQLNullException.
Depending on where the error came from, there might be meaningful information
you can retrieve from an exception using the getSQLState(), getErrorCode(), and
getMessage() methods. SQLJ errors, for example, include meaningful SQL states and
messages.
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Globalization Support in the Translator and Run Time
If errors are generated by Oracle JDBC driver or RDBMS at run time, look at the prefix
and consult the appropriate documentation:
• Oracle Database JDBC Developer's Guide for JDBC errors
• Oracle error message documentation for RDBMS errors (see "Related
Documents")
10.4 Globalization Support in the Translator and Run Time

The Oracle SQLJ implementation uses the Java built-in capabilities for globalization
support. This section discusses the following:
• Basics of SQLJ support for globalization and native character encoding, starting
with background information covering some of the implementation details of
character encoding and language support in the Oracle implementation
• Options available through the SQLJ command line that enable you to adjust your
Oracle Globalization Support configuration
• Extended Oracle globalization support
• Relevant manipulation outside of SQLJ for globalization support
Note:
Some prior knowledge of Oracle Globalization Support is assumed,
particularly regarding character encoding and locales. For information, refer
to:
Oracle Database Globalization Support Guide

• Character Encoding and Language Support
• SQLJ and Java Settings for Character Encoding and Language Support
• SQLJ Extended Globalization Support
• Manipulation Outside of SQLJ for Globalization Support
10.4.1 Character Encoding and Language Support

There are two main areas of SQLJ globalization support:
• Character encoding
There are three parts to this:
– Character encoding for reading and generating source files during SQLJ
translation
– Character encoding for generating error and status messages during SQLJ
translation
– Character encoding for generating error and status messages when the
application runs
• Language support
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This determines which translations of error and status message lists are used
when SQLJ outputs messages to the user, either during SQLJ translation or at
SQLJ run time.
Globalization support at run time is transparent to the user, presuming your SQLJ
source code and SQL character data use only characters that are within the database
character set. SQL character data is transparently mapped into and out of Unicode.
Note that for multi-language applications, it is advisable to use one of the following
options:
• Use a database whose character set supports Unicode.
• Even if your database character set does not support Unicode, specify that the
national language character set supports Unicode. (Refer to the Oracle Database
Globalization Support Guide.) In this case, you will typically use the SQLJ Unicode
character types described in "SQLJ Extended Globalization Support".
Note:
• The SQLJ translator fully supports Unicode 2.0 and Java Unicode
escape sequences. However, the SQLJ command-line utility does not
support Unicode escape sequences. You can use only native characters
supported by the operating system. Command-line options requiring
Unicode escape sequences can be entered in a SQLJ properties file
instead, because properties files do support Unicode escape sequences.
• Encoding and conversion of characters in your embedded SQL
operations and characters read or written to the database, are handled
by JDBC directly. SQLJ does not play a role in this. If online semantics-
checking is enabled during translation, however, then you will be warned
if there are characters within the text of your SQL data manipulation
language (DML) operations that might not be convertible to the database
character set.
• For information about JDBC globalization support functionality, refer to
the Oracle Database JDBC Developer's GuideOracle Database JDBC
Developer’s Guide.
Overview of Character Encoding

The character encoding setting for source files tells SQLJ two things:
• How source code is represented in .sqlj and .java input files that the SQLJ
translator must read
• How SQLJ should represent source code in .java output files that it generates
By default, SQLJ uses the encoding indicated by the JVM file.encoding property. If
your source files use other encodings, then you must indicate this to SQLJ so that
appropriate conversion can be performed.
Use the SQLJ -encoding option to accomplish this. SQLJ also passes the -encoding
setting to the compiler for it to use in reading .java files, unless the SQLJ -compiler-
encoding-flag is off.
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Note:
Do not alter the file.encoding system property to specify encodings for
source files. This might impact other aspects of your Java operation and
might offer only a limited number of encodings, depending on platform or
operating system considerations.
The system character-encoding setting also determines how SQLJ error and status
messages are represented when output to the user, either during translation or during
run time when the end user is running the application. This is set according to the
file.encoding property and is unaffected by the SQLJ -encoding option.
For source file encoding, you can use the -encoding option to specify any character
encoding supported by your Java environment. If you are using the Sun Microsystems
JDK, then these are listed in the native2ascii documentation, which you can find at
the following Web site:
https://docs.oracle.com/javase/8/docs/technotes/tools/windows/native2ascii.html
Dozens of encodings are supported by the Sun Microsystems JDK. These include
8859_1 through 8859_9 (ISO Latin-1 through ISO Latin-9), JIS (Japanese), SJIS (shift-
JIS, Japanese), and UTF8.
Character Encoding Notes

• A character that is not representable in the encoding used, for either messages
or source files, can always be represented as a Java Unicode escape sequence.
This is of the form \uHHHH, where each H is a hexadecimal digit.
• As a .sqlj source file is read and processed during translation, error messages
quote source locations based on character position (not byte position) in the input
encoding.
• Encoding settings, either set through the SQLJ -encoding option or the
Java file.encoding setting, do not apply to Java properties files, such as
sqlj.properties and connect.properties. Properties files always use the
encoding 8859_1. This is a feature of Java in general, not SQLJ in particular.
However, you can use Unicode escape sequences in a properties file. You can use
the native2ascii utility to determine escape sequences.
Overview of Language Support

SQLJ error and status reporting, either during translation or during run time, uses the
Java locale setting in the JVM user.language property. Users typically do not have to
alter this setting.
Language support is implemented through message resources that use key/value
pairs. For example, where an English-language resource has a key/value pair of
"OkKey", "Okay", a German-language resource has a key/value pair of "OkKey",
"Gut". The locale setting determines the message resources used.
SQLJ supports locale settings of en (English), de (German), fr (French), and ja

(Japanese).
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Note:
Java locale settings can support country and variant extensions in addition
to language extensions. For example, consider ErrorMessages_de_CH_var1,
where CH is the Swiss country extension of German and var1 is an additional
variant. SQLJ, however, currently supports only language extensions (de in
this example), ignoring country and variant extensions.
10.4.2 SQLJ and Java Settings for Character Encoding and Language
Support
The Oracle SQLJ implementation provides syntax that enables you to set the
following:
• The character encoding used by the SQLJ translator and Java compiler in
representing source code
Use the SQLJ -encoding option.
• The character encoding used by the SQLJ translator and run time in representing
error and status messages
Use the SQLJ -J prefix to set the Java file.encoding property.
• The locale used by the SQLJ translator and run time for error and status
messages
Use the SQLJ -J prefix to set the Java user.language property.
Setting Character Encoding for Source Code

Use the SQLJ -encoding option to determine the character encoding used in
representing .sqlj files read by the translator, .java files generated by the translator,
and .java files read by the compiler. The option setting is passed by SQLJ to the
compiler, unless the SQLJ -compiler-encoding-flag is off.
This option can be set on the command line or SQLJ_OPTIONS environment variable, as
in the following example:
-encoding=SJIS
Alternatively, you can set it in a SQLJ properties file, as follows:

sqlj.encoding=SJIS
If the encoding option is not set, then both the translator and compiler will use the
encoding specified in the JVM file.encoding property. This can also be set through
the SQLJ command line.
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See Also:
"Encoding for Input and Output Source Files (-encoding)" and "Compiler
Encoding Support (-compiler-encoding-flag)"Encoding for Input and Output
Source Files (-encoding)
Note:
If your -encoding is to be set routinely to the same value, then it is most
convenient to specify it in a properties file, as in the second example.
Setting Character Encoding and Locale for SQLJ Messages

Character encoding and locale for SQLJ error and status messages produced, during
both translation and run time, are determined by the Java file.encoding and
user.language properties. Although it is typically not necessary, you can set these
and other JVM properties in the SQLJ command line by using the SQLJ -J prefix.
Options marked by this prefix are passed to the JVM.
Set the character encoding as in the following example, which specifies shift-JIS
Japanese character encoding:
-J-Dfile.encoding=SJIS
Note:
Only a limited number of encodings might be available, depending on
platform or operating system considerations.
Set the locale as in the following example (which specifies Japanese locale):
The -J prefix can be used on the command line or SQLJ_OPTIONS environment variable
only. It cannot be used in a properties file, because properties files are read after the
JVM is invoked.
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Note:
• If your file.encoding, user.language, or any other Java property is

to be set routinely to the same value, it is most convenient to specify
-J settings in the SQLJ_OPTIONS environment variable. This way, you do
not have to repeatedly specify them on the command line. The syntax
is essentially the same as on the command line. For more information,
refer to "SQLJ_OPTIONS Environment Variable for Option Settings".
• Remember that if you do not set the SQLJ -encoding option, then setting
file.encoding will affect encoding for source files as well as error and
status messages.
• Be aware that altering the file.encoding property might have
unforeseen consequences on other aspects of your Java operations.
Also, any new setting must be compatible with your operating system.
See Also:
"Command-Line Syntax and Operations" and "Options to Pass to the Java
Virtual Machine"
SQLJ Command-Line Example: Setting Encoding and Locale

Following is a complete SQLJ command line, including JVM file.encoding and
user.language settings:
% sqlj -encoding=8859_1 -J-Dfile.encoding=SJIS -J-Duser.language=ja Foo.sqlj
This example uses the SQLJ -encoding option to specify 8859_1 (Latin-1) for source
code representation during SQLJ translation. This encoding is used by the translator
in reading the .sqlj input file and in generating the .java output file. The encoding is
then passed to the Java compiler to be used in reading the generated .java file. The
-encoding option, when specified, is always passed to the Java compiler unless the
SQLJ -compiler-encoding-flag is disabled.
For error and status messages output during translation of Foo.sqlj, the SQLJ
translator uses the SJIS encoding and the ja locale.
10.4.3 SQLJ Extended Globalization Support

The Oracle SQLJ implementation includes support for Java types (Unicode character
types) derived from existing character and stream types that convey expected usage
for globalization. In SQLJ it is not possible to use JDBC statement or result set
methods directly that otherwise serve the purpose of globalization support. If you are
interested in information about those methods, refer to the Oracle Database JDBC
Developer's Guide
If the database natively supports Unicode, then the types described in the
following section are unnecessary. In this case, globalization support will be handled
transparently. It is when the database does not natively support Unicode, but has a
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national language character set that does support Unicode, that you will typically use
these types (for columns that use the national language character set).
Java Types for Globalization Support

The Oracle SQLJ implementation provides a number of Java types for globalization
support. The following table notes the correspondence between these globalization
support types and general-use JDBC and SQLJ character and stream types. Each
globalization support type, except for NString, is a subclass of its corresponding JDBC
or SQLJ type.
Table 10-3 JDBC and SQLJ Types and Corresponding Globalization Types
JDBC and SQLJ Types Globalization Support Types

JDBC types:
oracle.sql.CHAR oracle.sql.NCHAR
java.lang.String oracle.sql.NString
oracle.sql.CLOB oracle.sql.NCLOB
SQLJ types:
sqlj.runtime.CharacterStream oracle.sqlj.runtime.NcharCharacterStream
sqlj.runtime.AsciiStream oracle.sqlj.runtime.NcharAsciiStream
(Deprecated; use CharacterStream.) (Deprecated; use NcharCharacterStream.)
sqlj.runtime.UnicodeStream oracle.sqlj.runtime.NcharUnicodeStream
(Deprecated; use CharacterStream.) (Deprecated; use NcharCharacterStream.)
In situations where your application must handle national language character strings,
either inserting them into or selecting them from national language character set
columns, use the globalization support types instead of the corresponding general-use
types.
Note:
• All globalization support types add automatic registration of intended

usage for IN and OUT parameters, but are otherwise identical in usage to
the corresponding JDBC or SQLJ type (including constructors).
• Use of globalization support types is unnecessary in iterator columns,
because the underlying network protocol supports national language
characters implicitly for the underlying result sets.
NString Class Usage and Notes

The oracle.sql.CHAR class, and therefore its NCHAR subclass, provides only
constructors that require explicit knowledge of the database character set. Therefore,
the oracle.sql.NString class, a wrapper for java.lang.String, is preferable in most
circumstances. The NString class provides simpler constructors and ensures that the
national language character form of use is registered with the JDBC driver.
Following are the key NString methods:
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• NString(String): This constructor creates an NString instance from an existing

String instance.
• String toString(): This method returns the underlying String instance.
• String getString(): This method also returns the underlying String instance.
The toString() method enables you to use the NString instance in string
concatenation expressions (such as "a"+b, where b is a string). The getString()
method, provided in the CHAR superclass, is supported as well for uniformity. In
addition, the member methods of the String class are carried over to the NString
wrapper class to enable you to write more concise code.
In SQLJ applications, for versions prior to Oracle Database 11g, you must use host
variables of the NString type to bind columns of the NCHAR type. For example, consider
the following table:
CREATE TABLE Tbl1 (
ColA CHAR
NColB NCHAR
)
To insert a row in this table through a SQLJ application, use a code similar to the
following:
...
String v_a = "\uFF5E";
NString v_nb = "\uFF5E";
#sql {INSERT INTO Tbl1 (ColA, NColB) VALUES (:v_a, :v_nb)};
...
Since Oracle Database 11g Release 1, SQLJ applications can use String variables to
bind NCHAR columns. Therefore, the preceding example can be rewritten as follows:
...
String v_a = "\uFF5E";
String v_nb = "\uFF5E";
#sql {INSERT INTO Tbl1 (ColA, NColB) VALUES (:v_a, :v_nb)};
...
However, if you want to use String host variable to bind to NCHAR columns, then you
must translate the SQLJ file with the -ncharconv SQLJ translator option, as follows:
sqlj -ncharconv [-options] app.sqlj
In the preceding command, options can be other SQLJ options and app.sqlj is the
SQLJ file that contains the code.
When this option is used, the setFormOfUse method will be generated for all binds to
character columns, that is, CHAR or NCHAR columns.
Note:
When the SQLJ file is compiled with the -ncharconv option, the
setFormOfUse method is used in the generated code for codegen=oracle.
For codegen=iso, this option information is passed to Oracle SQLJ run time,
which internally uses SetFormOfUse for bind at run time.
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The SQLJ application can use String host variable to retrieve data from the server
without using the -ncharconv option, because the information about the column type
is fetched at the client-side and JDBC internally sets the form for the appropriate
columns.
Note:
There may be a small difference in the performance when using the -
ncharconv option, depending on the database character set and national
charster set and the number of character columns in the table.
Globalization Support Examples

The following examples show use of the NString class:
• NString as IN argument
This example uses an NString instance as an input parameter to the database.
import oracle.sql.NString;
...
NString nc_name = new NString("Name with strange characters");
#sql { update PEOPLE
set city = :(new NString("\ufff2")), name = :nc_name
where num= :n };
...
• NString as OUT argument
This example uses an NString instance as an output parameter from the
database.
...
NString nstr;
#sql { call foo(:out nstr) };
System.out.println("Result is: "+nstr);
// or, explicitly: System.out.println("Result is: "+nstr.toString());
...
• NString as Result Set column
This example uses the NString type for an iterator column. Such usage is
superfluous, given that the underlying network protocol supports national language
characters implicitly, but harmless. This example also shows use of one of the
String methods, substring(), that is carried over to NString.
import oracle.sql.NCLOB;
...
#sql iterator NIter(NString title, NCLOB article);
NIter nit;
#sql nit = { SELECT article, title FROM page_table };
while (nit.next())
{
System.out.println("<TITLE>"+nit.title()+"</TITLE>");
...
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nit.article().substring(0, 1000); ...

}
Note:
Using the NCHAR type instead of the NString type for the preceding examples
requires the following changes:
• Use the appropriate NCHAR constructor. NCHAR constructors mirror CHAR
constructors, such as the following:
NCHAR(String str, oracle.sql.CharacterSet charset)
• Although you have the option of using either toString() or getString()
to retrieve the underlying String instance from an NString instance, for
an NCHAR instance you must use the getString() method. When using
the NString type, the toString() method is used automatically for string
concatenation.
10.4.4 Manipulation Outside of SQLJ for Globalization Support

This section discusses ways to manipulate your Oracle Globalization Support
configuration outside of SQLJ.
Setting Encoding and Locale at Application Run Time

As with any end user running any Java application, those running your SQLJ
application can specify JVM properties, such as file.encoding and user.language
directly, as they invoke the JVM to run your application. This determines the encoding
and locale used for message output as your application executes.
They can accomplish this as in the following example:
% java -Dfile.encoding=SJIS -Duser.language=ja Foo
This will use SJIS encoding and Japanese locale.
Using API to Determine Java Properties

In Java code, you can determine values of Java properties by using the
java.lang.System.getProperty() method, specifying the appropriate property. For
example:
public class Settings
{
public static void main (String[] args)
{
System.out.println("Encoding: " + System.getProperty("file.encoding")
+ ", Language: " + System.getProperty("user.language"));
}
}
You can compile this and run it as a standalone utility.

There is also a getProperties() method that returns the values of all properties, but
this will raise a security exception if you try to use it in code that runs in the server.
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Using native2ascii for Source File Encoding

If you are using a Sun Microsystems JDK, then there is an alternative to having SQLJ
do the character encoding for your source files. You can use the native2ascii utility
to convert sources with native encoding to sources in 7-bit ASCII with Unicode escape
sequences.
Note:
To use SQLJ to translate source created by native2ascii, ensure that the
JVM that invokes SQLJ has a file.encoding setting that supports some
superset of 7-bit ASCII. This is not the case with settings for EBCDIC or
Unicode encoding.
Run native2ascii as follows:

% native2ascii <options> <inputfile> <outputfile>
Standard input or standard output are used if you omit the input file or output file. Two
options are supported:
• -reverse (Reverse the conversion. Convert from Latin-1 or Unicode to native
encoding)
• -encoding <encoding>
For example:
% native2ascii -encoding SJIS Foo.sqlj Temp.sqlj
For more information, see the following Web site:

https://docs.oracle.com/javase/8/docs/technotes/tools/windows/native2ascii.html
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Performance and Debugging
This chapter discusses features, utilities, and tips to enhance performance of your
SQLJ application and to debug your SQLJ source code at run time. The following
topics are discussed:
• Performance Enhancement Features
• SQLJ Debugging Features
• SQLJ Support for Oracle Performance Monitoring
11.1 Performance Enhancement Features

The Oracle SQLJ implementation includes features to enhance performance by
making data access more efficient. These include the following:
• Row Prefetching
• Statement Caching
• Update Batching
• Column Definitions
• Parameter Size Definitions
See Also:
Your application will likely benefit from the default Oracle-specific code generation.
The generated code will be optimized with direct calls to Oracle Java Database
Connectivity (JDBC) driver, eliminating the overhead of intermediate calls to the SQLJ
run time, which in turn would call JDBC.
See Also:
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Performance Enhancement Features
Note:
The Oracle SQLJ implementation does not support batch fetches, which is
the fetching of sets of rows into arrays of values. However, you may be
able to use Oracle row prefetching to obtain some of the benefits of batch
fetching.
In addition to the preceding SQLJ performance enhancements, you can use optimizer
hints in the SQL operations within a SQLJ program, as you can in any Oracle SQL
operations.
The Oracle SQL implementation enables you to tune your SQL statements by using
"/*+" or "--+" comment notation to pass hints to Oracle SQL optimizer. The SQLJ
translator recognizes and supports these optimizer hints, passing them at run time as
part of your SQL statement.
You can also define cost and selectivity information for a SQLJ stored function, as
for any other stored function, using the extensibility features for SQL optimization in
Oracle Database 12c Release 2 (12.2). During SQL execution, the optimizer invokes
the cost and selectivity methods for the stored function, evaluates alternate strategies
for execution, and chooses an efficient execution plan.
See Also:
Oracle Database SQL Language Reference for more information
Note that using Oracle performance extensions in your code requires the following:
• Use the default Oracle-specific code generation, or customize profiles
appropriately.
For ISO standard code generation, the default customizer,
oracle.sqlj.runtime.util.OraCustomizer, is recommended.
• Use Oracle SQLJ run time when your application runs.
Oracle SQLJ run time and an Oracle JDBC driver are required by your application
whenever you customize profiles with Oracle customizer, even if you do not actually
use Oracle extensions in your code.
11.1.1 Row Prefetching

Standard JDBC receives the results of a query one row at a time, with each row
requiring a separate round trip to the database. Row prefetching enables you to
receive the results more efficiently, in groups of multiple rows each.
Use the setFetchSize() method of an ExecutionContext instance to set the number
of rows to be prefetched whenever you execute a SELECT statement (for SQLJ
statements using the particular ExecutionContext instance).
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The getFetchSize() method of an ExecutionContext instance returns the current

prefetch size, as an int value.
The following is an example of setting the prefetch size to 20 by getting the default
execution context instance of the default connection context instance and calling the
setFetchSize() method:
DefaultContext.getDefaultContext().getExecutionContext().setFetchSize(20);
It is also possible to set the prefetch size directly on the underlying OracleConnection
object using the JDBC application programming interface (API), but in SQLJ this is
discouraged.
To specify the number of rows to prefetch for queries that use a given connection
context instance, use the underlying JDBC connection, cast to an OracleConnection
instance. Following is an example that sets the prefetch value to 20 for your default
connection:
((OracleConnection)DefaultContext.getDefaultContext().getConnection()).setDefault
RowPrefetch(20);
Also, please note that the prefetch size set on the SQLJ connection context overrides
the prefetch size set on the underlying JDBC connection.
Each additional connection context instance you use must be set separately, as
desired.The prefetch value needs to be setup on each individual connection context.
For example, if ctx is an instance of a declared connection context class, set its
prefetch value as follows:
((Connection)ctx.getConnection()).setDefaultRowPrefetch(20);
ctx.getExecutionContext().setFetchSize(20);
There is no maximum row-prefetch value. The default is 10 in JDBC, and this is

inherited by SQLJ. This value is effective in typical circumstances, although you might
want to increase it if you receive a large number of rows.
11.1.2 Statement Caching

SQLJ offers a statement caching feature that improves performance by saving
executable statements that are used repeatedly, such as in a loop or in a method
that is called repeatedly. When a statement is cached before it is reexecuted, the
code does not have to be reparsed (either on the server or on the client), the
statement object does not have to be recreated, and the parameter size definitions
do not have to be recalculated. Without this feature, repeated statements would
have to be reparsed on the client, and perhaps in the server as well, depending on
whether a statement is still available in the general server-side SQL cache when it is
encountered again.
For Oracle-specific code generation, SQLJ statement caching relies on Oracle
JDBC driver, using the JDBC explicit caching mechanism. This is distinct from the
JDBC implicit caching mechanism, although there are interdependencies. With Oracle-
specific code, statement caching is controlled through connection methods.
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See Also:
For ISO code generation, SQLJ has its own statement caching mechanism through
functionality of the SQLJ run time. With ISO code, statement caching is controlled
through the Oracle customizer stmtcache option.
Note:
For Oracle-specific code generation, explicit caching is the only statement
caching mechanism that can be manipulated through SQLJ APIs. For the
discussion in this document, it will be referred to as SQLJ/explicit statement
caching.
In Oracle Database 12c Release 1 (12.1), the default statement cache size is set
to 5, provided the JDBC connection is being created by the connection context. If a
connection context is created using an already available JDBC connection or data
source, then the statement cache size will be set to that of the JDBC connection or the
data source.
Connection Context Methods for Statement Caching (Oracle-Specific Code)

If you use Oracle-specific code generation, which is the case with the SQLJ translator
default -codegen=oracle setting, use connection context methods for statement
caching functionality. Note that any statement cache size greater than 0 results in
SQLJ/explicit statement caching being enabled. By default, it is enabled with a cache
size of 5, that is, five statements.
The following Oracle-specific (nonstandard) static methods have been added to the
sqlj.runtime.ref.DefaultContext class, and are also included in any connection
context classes you declare:
• static void setDefaultStmtCacheSize(int)
This sets the default statement cache size for all connection contexts. This
becomes the initial statement cache size for any subsequently created instance
of any connection context class, not just the class upon which you call the method.
The method call does not affect connection context instances that already exist.
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Note:
setDefaultStmtCacheSize(int) affects the statement cache size only
for the connections that are created using the SQLJ connection contexts.
It does not affect the statement cache size for the connections that are
created using JDBC connections.
Consider the following two code snippets:
Example 1:
...
MyContext.setDefaultStmtCacheSize(10);
OracleConnection conn = DriverManager.getConnection(url, user,
passwd);
myctx = new MyContext(conn);
Example 2:
...
MyContext.setDefaultStmtCacheSize(10);
myctx = new MyContext(url, user, passwd,true);
In the preceding two examples, the statement cache size will be set
to 10 only in the second example. In the first example, the statement
cache size corresponding to this connection will not be affected because
the connection is created using the getConnection method of the
DriverManager interface from JDBC specification.
• static int getDefaultStmtCacheSize()

This retrieves the current default statement cache size for connection contexts.
And the following Oracle-specific instance methods have also been added to the
DefaultContext class and are included in any other connection context classes:
• void setStmtCacheSize(int) throws java.sql.SQLException

This sets the statement cache size for the underlying connection of the particular
connection context instance (overrides the default).
Note:
If SQLJ/explicit caching is already disabled, then setting the size to 0 leaves
it disabled. If it is already enabled, then setting the size to 0 leaves it
enabled, but renders it nonfunctional.
This verifies whether SQLJ/explicit statement caching is enabled for the underlying
connection of the connection context. If so, it returns the current statement cache
size. It can also return either of the following integer constants:
static int STMT_CACHE_NOT_ENABLED
static int STMT_CACHE_EXCEPTION
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It is possible for a getStmtCacheSize() call to cause a SQL exception.

However, for backward compatibility, this method does not throw the exception
directly. When an exception occurs, the method returns the constant
STMT_CACHE_EXCEPTION. In this case, you can call the getStmtCacheException()
method to find out what exception occurred.
If you call getStmtCacheSize() when SQLJ/explicit caching is disabled, then the
method returns the constant STMT_CACHE_NOT_ENABLED. This is distinguished from
a cache size of 0. Technically, it is possible for SQLJ/explicit caching to be enabled
(though useless) with a cache size of 0.
• java.sql.Exception getStmtCacheException()
See if there is a statement caching exception. There are two scenarios for using
this method:
– Call it if a getStmtCacheSize() call returns STMT_CACHE_EXCEPTION.
– Call it whenever you create a connection context instance with which you
want to use statement caching. This is because of automatic manipulation
that occurs with respect to statement cache size whenever you create a
connection context instance. If you care about statement caching for the
connection context instance, call getStmtCacheException() after creating the
instance, to verify there were no problems.
Enabling and Disabling Statement Caching (Oracle-Specific Code)

With Oracle-specific code, to reiterate what was stated earlier, any nonzero statement
cache size results in SQLJ/explicit caching being enabled. Because the default size is
5, statement caching is enabled by default.
You cannot explicitly disable SQLJ/explicit statement caching through SQLJ APIs,
although you can effectively disable it (render it nonfunctional) by setting the statement
cache size to 0. In this case, the connection context getStmtCacheSize() method
might return 0, not STMT_CACHE_NOT_ENABLED.
You can explicitly disable SQLJ/explicit statement caching or JDBC implicit caching,
through JDBC connection APIs. Because SQLJ/explicit caching and JDBC implicit
caching use the same cache size, there might sometimes be reason to do so. The
following methods are available through the OracleConnection class:
• void setExplicitCachingEnabled(boolean)
• boolean getExplicitCachingEnabled()
• void setImplicitCachingEnabled(boolean)
• boolean getImplicitCachingEnabled()
You have access to these methods if you retrieve the OracleConnection instance from
within a SQLJ connection context instance.
See Also:
"SQLJ Connection Context and JDBC Connection Interoperability"
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Note:
In SQLJ, JDBC implicit caching is disabled by default and remains disabled
unless you explicitly enable it through the setImplicitCachingEnabled()
method.
Key Interactions Between SQLJ/Explicit Caching and JDBC Implicit Caching

With regard to statement caching in Oracle-specific code, this document naturally
emphasizes SQLJ/explicit caching rather than JDBC implicit caching. If you do not use
JDBC code in your application, SQLJ/explicit caching is the only statement caching
that is relevant. However, there are situations where you might want to use both SQLJ
and JDBC code in your application, and in these circumstances you might also want to
use implicit caching.
SQLJ/explicit caching and JDBC implicit caching are enabled independently of each
other. Furthermore, you do not have access to the implicit cache through SQLJ.
However, there is a key interaction between the two, in that they share the same
cache size. If, for example, the statement cache size is 5, then you can have a
maximum of five statements cached for SQLJ/explicit caching and implicit caching
combined.
An important point related to this is that if you choose to effectively disable SQLJ/
explicit statement caching by setting the cache size to 0, then you have also effectively
disabled implicit caching.
Also be aware that if SQLJ/explicit caching is disabled, changing the cache size to a
value greater than 0 will enable it, but this does not affect whether implicit caching is
enabled.
JDBC Support for Statement Caching (ISO Code)

With ISO standard code generation, specified through the SQLJ translator -
codegen=iso setting, statement caching is a standard SQLJ feature that does
not require any particular JDBC driver. However, using a driver that implements
the sqlj.runtime.profile.ref.ClientDataSupport interface enables more robust
caching. Oracle Database 12c Release 1 (12.1) JDBC drivers implement this interface,
providing the following features:
• A separate cache for each database connection, instead of a single static cache
for the entire application
• The ability to share cached statements between multiple instances of a connection
context class that share the same underlying connection
When a single cache is used, as is the case with a generic JDBC driver that does not
implement ClientDataSupport, a statement executed in one connection can cause a
cached statement from another connection to be flushed (if the statement cache size,
the maximum number of statements that can be cached, is exceeded).
Oracle Customizer Option for Statement Cache Size (ISO Code)

With ISO standard code generation, statement caching is enabled in your application
by default with a cache size of 5 (the same default size as with Oracle-specific code)
when you use Oracle customizer, which is typically executed as part of Oracle SQLJ
translation.
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You can alter the statement cache size as desired, or effectively disable statement
caching with a cache size of 0, through the Oracle customizer stmtcache option. This
is set as -P-Cstmtcache=n, where n is an integer.
See Also:
"Oracle Customizer Statement Cache Size Option (stmtcache)"
If you use multiple connection context classes and, therefore, have multiple profiles,
you can set their statement cache sizes individually by running SQLJ (actually, the
customizer) separately for each profile.
At run time, the appropriate SQLJ profile determines the statement cache size for a
connection. This would be the profile that corresponds to the first connection context
class instantiated for this connection. Its statement cache size setting, if any, is
determined according to how you set the Oracle customizer stmtcache option when
you customized the profile. The run-time statement cache size for a connection is set
when the first statement on that connection is executed.
Additional Statement Caching Behavior

When a SQLJ connection context object is instantiated, if the statement cache size
on the underlying JDBC connection is smaller than the default size for the connection
context class, then the SQLJ run time will attempt to increase the JDBC statement
cache size to the connection context default value. This manipulation occurs even with
ISO code generation, enabling explicit statement caching in the process, although this
is actually of no relevance in the ISO code case.
If, on the other hand, the actual JDBC statement cache size is larger, then the SQLJ
run time will not attempt to perform a change in the cache size. The SQLJ run time
checks the actual JDBC cache size against the default size set whenever it creates a
SQLJ connection context instance.
It is important to note that these methods have the same effect regardless of the
context class on which they are issued, because they modify or report the same
underlying static field.
As an example, assume the following connection context class declarations:
#sql context CtxtA;
#sql context CtxtB;
In this case, each of the following three code instructions has the effect that whenever
a new SQLJ connection context instance is subsequently created, it will not try to
enable SQLJ/explicit statement caching:
sqlj.runtime.ref.DefaultContext.setDefaultStmtCacheSize(0);
CtxtA.setDefaultStmtCacheSize(0);
CtxtB.setDefaultStmtCacheSize(0);
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Note:
If a SQLJ connection context instance is created on an underlying
JDBC pooled connection, then SQLJ will not be able to change
the JDBC statement cache size. For Oracle-specific code, you
can retrieve the resulting exception through the connection context
getStmtCacheException() method. In this case, the desired JDBC
statement cache size must be set explicitly on the underlying physical
connections. For data sources, the cache size is set through vendor-specific
data source attributes.
SQLJ/explicit caching and JDBC implicit caching functionality have different semantics
and behaviors. As noted earlier, SQLJ statement caching applies only to single
statements used repeatedly, such as in a loop or through repeated calls to the same
method. Consider the following example:
...
#sql { same SQL operaton }; // occurrence #1
...
Java code
...
...
Java code
...
...
Assume the three SQL operations are identical, including white space.
SQLJ caching would consider these three occurrences of the same SQL operation
to be three different statements. They will occupy three separate slots in the cache.
JDBC implicit caching, however, would recognize these as identical statements, using
only a single cache slot for all three. The statement would be reused for occurrence #2
and occurrence #3.
Statement Caching Limitations and Notes

Using a statement cache, even of size 1, will improve the performance of almost any
SQLJ application. Be aware of the following, however:
• There is no benefit if each statement is executed only once.
• Try to avoid interleaving statements executed once with statements executed
multiple times. The statements being executed only once would needlessly take
up space in the statement cache, which becomes an issue when you reach the
statement cache size limit. As an alternative, if you use ISO code generation you
can use a separate connection context class for statements that are executed only
once and disable statement caching for that connection context class.
• Distinct statements with identical SQL operations are treated the same way as any
distinct statements. Each is processed and cached separately. As an alternative,
put the SQL operation in a method and call the method repeatedly, instead of
using distinct statements.
• Be careful in choosing an appropriate statement cache size. If it is too small,
then the cache might fill up resulting in statements being flushed before they are
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reexecuted. If it is too large, then database resources or program resources may

be exhausted.
Also be aware of the following general notes regarding statement caching:
• With Oracle-specific code generation, using separate SQLJ connection context
instances to have separate statement caching behavior will not work if the
connection contexts share the same underlying JDBC connection instance. This is
because under Oracle-specific code generation, SQLJ uses the JDBC statement
cache.
• For Oracle applications, the statement cache size plus the maximum number
of open JDBC statements in your application, both directly and through SQLJ,
should be less than the maximum number of cursors available for a session. This
is because the maximum number of cursors defines the maximum number of
statements that can be open simultaneously.
• Using a statement cache generally does not change the execution semantics of an
operation itself, although there are some scenarios where it does. For example, if
you have a statement that throws an exception when its resources are released,
then using a cache would mean that the exception would not be thrown until the
connection is closed or the statement is flushed from the cache, which happens
when the cache size is exceeded.
11.1.3 Update Batching

Update batching, referred to as batch updates in the Sun Microsystems JDBC 2.0
specification, allows UPDATE, DELETE, and INSERT statements that are batchable and
compatible to be collected into a batch and sent to the database for execution at
once, saving round trips to the database. This feature is included in the JDBC and
SQLJ specifications and is supported by the Oracle JDBC and SQLJ implementations.
Update batching is typically used for an operation that is executed repeatedly within a
loop.
In SQLJ, update batching is tied to execution context usage. This feature is enabled or
disabled in each execution context, independently of any other execution context, and
each execution context instance maintains its own batch.
Note:
Be aware of the following for update batching:
• You must use the default Oracle-specific code generation or, for ISO
code generation, customize your application with Oracle customizer.
• It is highly advisable to disable auto-commit mode. This gives you control
of what to commit and what to roll back in case of an error during batch
execution.
Batchable and Compatible Statements

Two criteria determine whether a statement can be added to an existing batch of
statements:
• Is it batchable? You cannot batch some kinds of statements under any
circumstances.
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• Is it compatible with statements in the existing batch?

For SQLJ, the following kinds of statements are batchable:
• UPDATE
• INSERT
• DELETE
However UPDATE and INSERT statements with one or more stream host expressions are
not batchable.
In SQLJ, only multiple instances of the same statement are compatible. This can occur
in either of two circumstances:
• A statement is executed repeatedly in a loop.
• A statement is executed in a method, and the method is called repeatedly.
Enabling and Disabling Update Batching

SQLJ performs update batching separately for each execution context instance. Each
one can have update batching enabled independently of your other execution context
instances, and each maintains its own batch.
To enable or disable update batching for a particular execution context instance, use
the setBatching() method of that execution context instance. This method takes
boolean input, as follows:
...
ExecutionContext ec = new ExecutionContext();
ec.setBatching(true);
...
or:
...
ec.setBatching(false);
...
Update batching is disabled by default.
Note:
The setBatching() method does not affect an existing statement batch.
Neither enabling nor disabling update batching causes an existing batch to
be executed or canceled.
Use the isBatching() method of an execution context instance to determine if update

batching is enabled for that execution context:
...
boolean batchingOn = ec.isBatching();
This does not, however, indicate whether a batch is currently pending.
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Explicit and Implicit Batch Execution

You can explicitly execute a pending update batch as desired, but it might also be
implicitly executed under certain circumstances.
Note:
It is important to be aware of what happens when an exception occurs in the
middle of a batch execution.
Use the executeBatch() method of the execution context instance to explicitly execute
an update batch. This method returns an int array of update counts.
Following is an example of explicitly executing a batch:

...
...
double[] sals = ...;
String[] empnos = ...;
for (int i = 0; i < empnos.length; i++)
{
#sql [ec] { UPDATE employees SET salary = :(sals[i]) WHERE employee_id = :
(empnos[i]) };
}
int[] updateCounts = ec.executeBatch();
...
Note:
If you invoke executeBatch() when the execution context instance has no
pending batch, then the method returns null.
When a pending update batch exists, it is implicitly executed in the following

circumstances:
• An executable statement is encountered that is not batchable. In this case the
existing batch is executed first, then the nonbatchable statement is executed.
• An update statement is encountered that is batchable, but is not compatible with
the statements in the existing batch, in other words, is not an instance of the same
statement. In this case the batch is executed, then a new batch is created, starting
with the incompatible statement.
• A predefined batch limit, that is, a specified number of statements, is reached.
Following is an example. First one batch is created and executed implicitly when an
unbatchable statement is encountered, then a new batch is created and executed
implicitly when a batchable, but incompatible, statement is encountered:
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...
/* Statements in the following loop will be placed in a batch */
{
(empnos[i]) };
}
/* a SELECT is unbatchable so causes the batch to be executed */

double avg;
#sql [ec] { SELECT avg(salary) INTO :avg FROM employees };
/* Statements in the following loop will be placed in a new batch */

double[] comms = ...;
{
#sql [ec] { UPDATE employees SET commission_pct = :(comms[i]) WHERE
employee_id = :(empnos[i]) };
}
/* the following update is incompatible with the second batch, so causes it to

be executed */
int smithdeptno = ...;
#sql [ec] { UPDATE employees SET department_no = :deptno WHERE first_name =
'Smith' };
To obtain the update count array for a batch executed implicitly, invoke the
getBatchUpdateCounts() method of the execution context instance. This returns the
update counts for the last batch to be executed successfully in this execution context
instance. The following code statement could be inserted after the SELECT and after the
last UPDATE:
int[] updateCounts = ec.getBatchUpdateCounts();
Note:
If no update batch has been executed successfully for the execution context
instance, then getBatchUpdateCounts() returns null.
Canceling a Batch
To cancel the batch that is pending in an execution context, use the cancel() method
of the execution context instance. You can, for example, cancel a batch that has been
executed, but not yet committed, in the event that an exception occurred during batch
execution. Following is an example:
...
...
{
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(empnos[i]) };
if (!check(sals[i], empnos[i])) //assume "check" is a user-supplied function
{
ec.cancel();
throw new SQLException("Process canceled.");
}
}
try
{
int[] updateCounts = ec.executeBatch();
} catch ( SQLException exception) { ec.cancel(); }
...
When you cancel a batch, the next batchable statement will start a new batch.
Note:
• Calling cancel() will also cancel any statement currently executing.

• Canceling a batch does not disable update batching.
Execution Context Update Counts

In the Oracle Database 12c Release 1 (12.1) SQLJ implementation, the array of
update counts returned by the executeBatch() or getBatchUpdateCounts() method of
an execution context instance does not contain counts of the number of rows updated
by the batched statements, but simply values indicating whether each statement was
successful. So its functionality differs from that of the single update count returned
by the getUpdateCount() method of the execution context instance when batching is
not enabled. As statements are batched, and after batch execution, the single update
count returned by getUpdateCount() is also affected.
In a batch-enabled environment, the value available from the getUpdateCount()

method of the execution context instance is modified after each statement is
encountered. It will be updated with one of several ExecutionContext class static int
constant values, as follows:
• NEW_BATCH_COUNT: Indicates that a new batch was created for the last statement
encountered.
• ADD_BATCH_COUNT: Indicates that the last statement encountered was added to an
existing batch.
• EXEC_BATCH_COUNT: Indicates that the pending batch was executed, either explicitly
or implicitly, after the last statement was encountered.
If you want to refer to these constants, then use the following qualified names:
ExecutionContext.NEW_BATCH_COUNT
ExecutionContext.ADD_BATCH_COUNT
ExecutionContext.EXEC_BATCH_COUNT
After a batch has been executed, either explicitly or implicitly, the array of values
returned by executeBatch() or getBatchUpdateCounts() indicates only whether the
statements executed successfully. There is an array element for each batched
statement. In accordance with the JDBC 2.0 specification, a value of -2 for an array
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element indicates that the corresponding statement completed successfully, but that
the number of rows it affected is unknown.
Checking all the array values after execution of a batch would not be meaningful. As
currently implemented, the only useful test of this array would be to verify the number
of statements that were in the batch prior to execution, by checking the number of
elements in the array after a successful execution (essentially, after a batch execution
that does not produce an exception).
Note that the update counts array is not modified as statements are batched, only as
the batch is executed.
Setting a Batch Limit

You can specify that each update batch be executed after a predefined number of
statements have been batched, before the next statement would be added. Use
the setBatchLimit() method of the execution context instance, inputting a positive,
nonzero integer as follows:
...
ec.setBatchLimit(10);
...
for (int i = 0; i < 20; i++)
{
#sql [ec] { UPDATE emp1 SET sal = :(sals[i]) WHERE empno = :(empnos[i]) };
}
This loop is executed 20 times, with the statements being batched and the batch being
executed during the 11th time through the loop, before the 11th statement would be
added to the batch. Note that the batch would not be executed a second time in the
loop, however. When your application exits the loop, the last ten statements would still
be in the batch and would not be executed until another statement is encountered or
you execute the batch explicitly.
You can use two special static int constants of the ExecutionContext class as input
to the setBatchLimit() method:
• AUTO_BATCH: Enables the SQLJ run time to determine the batch limit.
• UNLIMITED_BATCH (default): Specifies that there is no batch limit.
For example:
...
ec.setBatchLimit(ExecutionContext.AUTO_BATCH);
...
or:
ec.setBatchLimit(ExecutionContext.UNLIMITED_BATCH);
...
To check the current batch limit, use the getBatchLimit() method of the execution
context instance.
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Batching Incompatible Statements

If you want to batch a statement that is incompatible with statements in an existing
batch, without implicitly executing the existing batch, then you will have to use a
separate execution context instance. Following is an example:
...
ExecutionContext ec1 = new ExecutionContext();
ec1.setBatching(true);
ExecutionContext ec2 = new ExecutionContext();
ec2.setBatching(true);
...
{
#sql [ec1] { UPDATE emp1 SET sal = :(sals[i]) WHERE empno = :(empnos[i]) };
#sql [ec2] { UPDATE emp2 SET sal = :(sals[i]) WHERE empno = :(empnos[i]) };
}
int[] updateCounts1 = ec1.executeBatch();
int[] updateCounts2 = ec2.executeBatch();
...
Note:
This example assumes that the two UPDATE statements are completely
independent of each other. Do not batch interdependent statements in
different execution contexts because you cannot completely assure the order
in which they will be executed.
An alternative is to use a single execution context and separate loops so that all the
EMP1 updates are batched and executed prior to the EMP2 updates:
...
...
{
}
{
}
ec.executeBatch();
...
This example executes the first batch implicitly and the second batch explicitly.
Using Implicit Execution Contexts for Update Batching

All the update batching examples so far have created and specified explicit execution
context instances. This is not necessary, however, given that every connection context
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instance has an implicit execution context instance. For example, you can access the
implicit execution context instance of the default connection as follows:
DefaultContext.getDefaultContext().getExecutionContext().setBatching(true);
...
{
#sql { UPDATE employees SET salary = :(sals[i]) WHERE employee_id = :
(empnos[i]) };
}
// implicitly execute the batch and commit
#sql { COMMIT };
Or, you could execute the batch explicitly, as follows:

DefaultContext.getDefaultContext().getExecutionContext().executeBatch();
General Cautions Regarding Update Batching

If you use update batching, especially if you mix statements using an unbatched
execution context instance with statements using a batched execution context
instance, then remember the following points:
• If an unbatched statement depends on a batched statement, then be sure the
batch is executed prior to the unbatched statement.
• A JDBC COMMIT or ROLLBACK operation, that is, an auto-commit or any explicit use
of the commit() or rollback() method of a JDBC Connection instance, does not
execute pending statements in a batch.
It is important to note, however, that using a SQLJ COMMIT or ROLLBACK statement,
such as follows, will execute pending statements in a batch:
#sql { COMMIT };
or:
#sql { ROLLBACK };
This is another reason that you should always commit or roll back changes using
#sql syntax, which cleans up both SQLJ resources and JDBC resources.
• When a batch is implicitly executed as a result of an unbatchable or incompatible
statement being encountered, the batch is executed before the unbatchable
or incompatible statement is executed, but after the input parameters of that
statement have been evaluated and passed to the statement.
• If you no longer intend to use a particular batch-enabled execution context
instance, then explicitly execute or cancel its pending batch to free resources.
Error Conditions During Batch Execution

In the event that a statement causes an exception in the middle of a batch execution,
be aware of the following:
• Batched statements following the statement that caused the exception are not
executed.
• Batched statements that had already been executed prior to the exception are not
rolled back.
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• If the batch where the exception occurred was executed implicitly as the result
of another (unbatchable or incompatible) statement being encountered, that
statement is not executed.
Note:
Presumably you have disabled auto-commit mode when using update
batching. This gives you commit/rollback control in case of an error during
batch execution.
When an exception occurs during batch execution under JDBC 2.0 or later, it
is typically an instance of the standard java.sql.BatchUpdateException class, a
subclass of the java.sql.SQLException class. The BatchUpdateException class has
a getUpdateCounts() method that, for batched statements successfully executed
before the exception occurred, returns an array of update counts equivalent to what
would be returned by the executeBatch() or getBatchUpdateCounts() method of the
ExecutionContext class.
Recursive Call-ins and Update Batching

Execution of SQLJ stored procedures, where one calls the other, can result in
situations where the two procedures are simultaneously using the same execution
context instance. The update-batching flag, set using the setBatching() method
of the execution context instance, would act in the same way as other execution
context attributes. Regardless of which stored procedure sets it, it would affect the next
executable statement in either stored procedure.
For this reason, update batching is automatically disabled in the server whenever a
recursive call-in occurs. The pending batch is executed, and no batching occurs in the
recursively invoked procedure. To avoid this behavior, use explicit execution context
instances in batch-enabled stored procedures.
11.1.4 Column Definitions

The Oracle SQLJ implementation reflects Oracle JDBC support for column type and
size definitions. Depending on the driver implementation, which differs somewhat
among the different Oracle JDBC drivers, registering column types and sizes can save
a trip to the database for each query. In particular, this is true for Oracle JDBC Thin
driver and use of positional iterators.
Oracle Implementation of Column Definitions

If you enable column definitions, then the Oracle SQLJ implementation takes the
following steps to automatically register column types and sizes:
• During customization or during translation when the default Oracle-specific code
generation is used, SQLJ connects to a specified database schema to determine
types and sizes of columns being retrieved. With ISO standard SQLJ code
generation, the column defaults become part of the SQLJ profile. This can be
accomplished during the customization step of source code translation or during
separate customization of an existing profile.
• When your application executes, the SQLJ run time will use the column
information to register the column types and sizes with the JDBC driver, using
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a call to the defineColumnType() method available in the Oracle JDBC statement

classes.
Customizer and Translator Options for Column Definitions

To enable column definitions, set SQLJ options as follows:
• Enable the optcols flag. For Oracle-specific code generation, use the SQLJ
translator -optcols option. For ISO standard code generation, use either the
translator option or the Oracle customizer option (-P-Coptcols on the SQLJ
command line).
• Set the user, password, and URL for a database connection. For Oracle-specific
code generation, this is through the SQLJ translator -user, -password, and -url
options. For ISO standard code generation, this can be through the translator
options or you can separately use the customizer options (-P-user, -P-password,
and -P-url on the SQLJ command line). In addition, set the JDBC driver
class (-P-driver on the SQLJ command line) if you are not using the default
OracleDriver class.
For information about the customizer options, refer to the optcols section under
"Overview of Customizer-Specific Options", and the user, password, url, and driver
sections under "Overview of Customizer Harness Options".
11.1.5 Parameter Size Definitions

The Oracle JDBC and SQLJ implementations enable you to optimize JDBC resource
allocation by defining parameter sizes (sizes of Java host variables) used as any of the
following:
• Input or output parameters in stored procedure or function calls
• Return values from stored function calls
• Input or output parameters in SET statements
• Input or output parameters in PL/SQL blocks
Oracle Implementation of Parameter Size Definitions

Oracle implements parameter size definitions through option settings, in combination
with hints embedded in source code comments. For ISO standard SQLJ code
generation, Oracle customizer options are available. For the default Oracle-specific
code generation, equivalent SQLJ translator options are available.
Use options and hints as follows:
• Enable parameter size definitions through the SQLJ translator or Oracle
customizer parameter definition flag.
• Specify default sizes for particular data types through the SQLJ translator or
Oracle customizer parameter default size option.
• Override data type default sizes for particular parameters by embedding hints in
source code comments, following a prescribed format.
For any given host variable, when parameter size definitions are enabled, resources
are allocated according to the source code hint if there is one. If there is no source
code hint, then the default size for the corresponding data type is used if one was
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specified. If there is no source code hint or appropriate default size, then maximum
resources are allocated according to the JDBC implementation.
When your application executes, the parameter sizes are registered through calls to
the defineParameterType() and registerOutParameter() methods available in the
Oracle JDBC statement classes.
Note:
If you do not enable the parameter definition flag, then parameter size
defaults and source code hints will be ignored and maximum or default
resources will be allocated according to the JDBC implementation.
Customizer and Translator Options for Parameter Size Definitions

Use the following SQLJ options for parameter size definitions:
• Use the optparams flag to enable parameter size definitions. For Oracle-specific
code generation, use the SQLJ translator -optparams option. For ISO standard
code generation, use either the translator option or the Oracle customizer option,
-P-Coptparams on the SQLJ command line.
• Use optparamdefaults to set default sizes for particular data types. For Oracle-
specific code generation, use the SQLJ translator -optparamdefaults=xxxx
option. For ISO standard code generation, use either the translator option or the
Oracle customizer option, -P-Coptparamdefaults=xxxx on the SQLJ command
line.
Source Code Hints for Parameter Size Definitions

Embed source code hints for parameter size definitions within your SQLJ statements
in the following format (you can add white space within the comment, as desired):
/*(size)*/
The size is in bytes. Hints are ignored if the optparams flag is disabled.
You can override the default parameter size, without specifying a new size (leaving
size allocation to the JDBC implementation), as follows:
/*()*/
Here is an example:
byte[] hash;
String name=Tyrone;
String street=2020 Meryl Street;
String city=Wichita;
String state=Kansas;
String zipcode=77777;
#sql hash = { /* (5) */ VALUES (ADDR_HASH(:name /* (20) */, :street /* () */,
:city, :state, :INOUT zipcode /* (10) */ )) };
A hint for a result expression, such as the result expression hash in the example, must
be the first item appearing inside the brackets of the SQLJ statement, as shown. Hints
for input and output host variables must immediately follow the variables, as shown.
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SQLJ Debugging Features
The example sets parameter sizes as follows:

• hash: 5 bytes
• name: 20 bytes
• street: override default, but with no setting (leave allocation up to JDBC)
• city: none (use appropriate data type default, if any)
• state: none (use appropriate data type default, if any)
• zipcode: 10 bytes
Note:
If any parameter size is altered such that its actual size exceeds its
registered size at run time, then a SQL exception will be thrown.
11.2 SQLJ Debugging Features

This section summarizes debugging features in the Oracle SQLJ implementation. It
covers the following topics:
• SQLJ -linemap Flag for Debugging
• Overview of the AuditorInstaller Specialized Customizer
• Overview of Developing and Debugging in Oracle10g JDeveloper
11.2.1 SQLJ -linemap Flag for Debugging

The -linemap flag instructs SQLJ to map line numbers from a SQLJ source code file
to locations in the corresponding .class file. This will be the .class file created during
compilation of the .java file generated by the SQLJ translator. As a result of this,
when Java run-time errors occur, the line number reported by the Java virtual machine
(JVM) is the line number in the SQLJ source code, making it much easier to debug.
If you are using the Sun Microsystems jdb debugger, then use the -jdblinemap option
instead of the -linemap option. The options are equivalent, except that -jdblinemap
does some special processing, necessitated by the fact that jdb does not support Java
source files with file name extensions other than the .java extension.
Note:
If you are translating in the server, then class schema objects created during
server-side translation automatically reference line numbers that map to the
SQLJ source code. This is equivalent to enabling the -linemap option when
you translate on a client.
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SQLJ Support for Oracle Performance Monitoring
11.2.2 Overview of the AuditorInstaller Specialized Customizer

For ISO code generation, SQLJ provides a special customizer, AuditorInstaller.
This customizer will insert sets of debugging statements, known as auditors, into
profiles specified on the SQLJ command line. These profiles must already exist from
previous customization. The debugging statements will execute during SQLJ run time
(when someone runs your application), displaying a trace of method calls and values
returned.
Use the customizer harness debug option, preceded by -P- as with any general
customization option, to insert the debugging statements.
See Also:
"AuditorInstaller Customizer for Debugging"
11.2.3 Overview of Developing and Debugging in Oracle10g

JDeveloper
The Oracle SQLJ product is fully integrated into the Oracle10g JDeveloper visual
programming tool.
JDeveloper also includes an integrated debugger that supports SQLJ. SQLJ
statements, as with standard Java statements, can be debugged in-line as your
application executes. Reported line numbers are according to the line numbers in your
SQLJ source code (as opposed to in the generated Java code).
11.3 SQLJ Support for Oracle Performance Monitoring

FUTURE (post-10i/10.1): SQLJ DMS monitoring stored locally as hierarchy; -
sqlmonitor.dms=false setting (for storing locally instead of sending to DMS);use of
SQLJ DMS APIs (to access results stored locally).
FUTURE (post-10i/10.1): SQLJ -components=append; multiple translation runs for
DMS.
FUTURE: Update Oracle9iAS to Oracle10iAS when appropriate.
The following sections discuss Oracle SQLJ implementation support for Oracle
Dynamic Monitoring Service (DMS):
• Overview of SQLJ DMS Support
• Summary of SQLJ Command-Line Options for DMS
• SQLJ Run-Time Commands and Properties File Settings for DMS
• SQLJ DMS Sensors and Metrics
• SQLJ DMS Examples
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11.3.1 Overview of SQLJ DMS Support

DMS enables users to measure performance statistics for SQLJ programs. SQLJ
support for DMS focuses on the overall performance per SQL statement, such as
its execution time, but can also provide method-level or class-level performance
information, such as with Oracle JDBC support for DMS. You can choose a client-side
perspective, such as the overall performance of each #sql statement, a server-side
perspective, such as server-side tracing of each SQL operation, or both.
Instrumenting a program, which is specified at translation time through SQLJ options,
is required in order to enable DMS setup. Specifically, instrumenting is the process of
inserting DMS calls into system or application code for measuring its performance.
At run time, any components that were instrumented during translation can be
monitored during execution, according to instructions in a SQLJ DMS properties file.
During run time, statistics are sent to DMS through DMS APIs. This requires a running
DMS system in your environment. You can then access the statistics through DMS
tools.
The statistics are intended to help you track and understand SQL statement
performance and are reported according to the following hierarchy (from top to
bottom):
1. Application: The application, in this context, is defined to consist of the SQLJ and
Java components specified in the SQLJ command line for translation. However,
only the SQLJ components can be instrumented.
2. Module: A module corresponds to a Java package.
3. Action: An action maps to a Java class defined in a SQLJ program.
4. Statement: A statement is a SQL statement in a SQLJ program.
The following DMS statistics are measured for client-side monitoring:
• Elapsed time for each #sql statement, including parsing and execution
• Get-next time, the time to execute each next() call
• Get-XXX time, the time to extract a database column through each getXXX() call
These statistics require the DMS library to be in your classpath at both translation
time and run time, so are not supported on the server, where the DMS library is not
available. Server-side SQLJ code cannot be monitored in the way that client-side code
can.
The following statistics are measured for server-side SQL monitoring of your SQLJ
client program:
• Parsing time
• Execution time
• Fetching time
These statistics are available from the Oracle Database 12c Release 1 (12.1) trace
file, through SQL tracing functionality. This is independent of DMS, but you can enable
it through the SQLJ DMS properties file sqlmonitor.servertracing setting.
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See Also:
"SQLJ Run-Time Commands and Properties File Settings for DMS"
For a client-side SQLJ program, you can use both DMS statistics and server-side
tracing. For example, from DMS you can get the total time required for a #sql
statement that consists of a query, then from server-side tracing you can find out how
much of that time was actually spent executing the SQL query in the server.
Note:
• DMS support currently requires Oracle-specific code generation, which is

enabled by default.
• In Oracle Database 12c Release 1 (12.1), instrumented code requires
Java Development Kit (JDK) 6.
• Only SQLJ declarations and statements are instrumented.
• The DMS library is in the file dms.jar, in ORACLE_HOME/oc4j/lib in
Oracle Database 12c Release 1 (12.1)
11.3.2 Summary of SQLJ Command-Line Options for DMS

FUTURE (post-10i/10.1): -components=append; multiple translation runs.
The Oracle SQLJ implementation provides following translator front-end options to
support DMS:
• -instrument: Enable instrumentation and designate a name for the application
(the collective of the components being translated).
• -components: Specify the components (packages and classes) to be instrumented.
Typically you would enable instrumentation by specifying a desired application name in
the -instrument setting, optionally specifying a package as well. Or specify a setting
of true to use the default application, defaultApp. For DMS instrumentation, the term
application refers to all the SQLJ and Java components specified for translation in the
SQLJ command line.
If instrumentation is enabled, a SQLJ DMS properties file is created according to the
-instrument setting, starting from the current directory, and also according to any
setting of the SQLJ -d option. For a setting of true, the properties file is named
sqlmonitor.properties in the current directory.
Note:
A setting of -instrument is equivalent to -instrument=true. A setting of
-instrument=false (the default) disables instrumentation.
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As a simple example, a setting of -instrument=myapp will result in creation of

the properties file myapp.properties. Now consider the following example, for an
application name of stock and a package name of com.acme:
% sqlj -instrument=com.acme/stock -d /home Stock.sqlj Trading.sqlj
Because of the -d option, the /home/com/acme/stock.properties file is created.
When instrumentation is enabled through the -instrument option, use the -

components option to specify the subset of translated components to be instrumented
for DMS monitoring, typically most or all of them to allow flexibility in what you can
monitor during run time. Specify a comma-delimited list of packages (to instrument
all classes in each package) or specific classes, or use the default all setting to
instrument all components being translated.
For example, to instrument the classes Stock and Trading:
% sqlj ... -components=com.acme.Stock,com.acme.Trading
At run time, instrumented components are monitored according to what is specified

in the SQLJ DMS properties file. Any components that are not instrumented during
translation cannot be monitored during run time, regardless of what is specified in the
properties file.
11.3.3 SQLJ Run-Time Commands and Properties File Settings for

DMS
While the SQLJ -instrument option specifies whether the SQLJ translator instruments
files for monitoring capability, it is the SQLJ DMS properties file that actually
determines what is monitored and how, at run time.
This properties file is created by SQLJ during translation, and then you can modify
it as desired. Be aware that if you run SQLJ again, however, SQLJ overwrites the
properties file. Any changes that you made are lost.
Settings in the SQLJ DMS properties file are as follows:
• sqlmonitor.components: This is a comma-delimited list of components (packages
or classes) that have been instrumented. This is set automatically by the translator
to reflect the setting of the SQLJ -components option.
• sqlmonitor.monitorcomp: This is a comma-delimited list of components
(packages or classes) to be monitored and denotes a subset of the components
in the sqlmonitor.components setting. The setting for sqlmonitor.monitorcomp
is initially determined during translation to reflect the sqlmonitor.components
setting, but you can then adjust it as desired. A setting of all means to monitor all
components listed in the sqlmonitor.components setting.
• sqlmonitor.dms: This boolean flag, with a default value of true, specifies whether
to deliver collected statistics to DMS. This requires a running Oracle Application
Server 10g instance where you can use DMS tools. Statistics can be accessed
through a Web browser or written into a file.
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Note:
A setting of sqlmonitor.dms=false is not currently supported.
FUTURE (post-10i/10.1): Support for sqlmonitor.dms=false. (Is DMS library still

required if sqlmonitor.dms=false?)
• sqlmonitor.sysurl: For server-side tracing, this specifies the database URL.
• sqlmonitor.sysuser: For server-side tracing, this specifies the database user.
This user must have sysdba privileges.
• sqlmonitor.syspassword: For server-side tracing, this specifies the password for
the sysuser.
Note:
For sysurl, sysuser, and syspassword, default values are according to
the user, password, and url values supplied to SQLJ, either through the
SQLJ command line or through the SQLJ properties file.
• sqlmonitor.servertracing: Use this to enable server-side tracing, to collect

performance statistics in the server, such as for SQL operations. Supported
settings are true or false (the default).
• sqlmonitor.dumpfile: If delivering statistics to DMS, then you can use this option
to specify a file into which the DMS tool writes the statistics. The default is
application_name.mtr, where application_name is according to the -instrument
option setting (or is defaultApp by default).
11.3.4 SQLJ DMS Sensors and Metrics

Sensors are used by DMS to calculate performance metrics during the execution
of instrumented SQLJ programs and delivered to DMS. They are organized as a
hierarchy, with each sensor having a path name. Here are typical sensor formats:
/SQLJ/application_name/sensor_name
/SQLJ/application_name/module/sensor_name
/SQLJ/application_name/module/class/sensor_name
/SQLJ/application_name/module/class/linenum/sensor_name
A sensor is an instance of the oracle.dms.instrument.Sensor class, which has

methods for calculating and organizing performance statistics. For example, there are
methods to instruct the sensor to derive additional metrics and to get the value of one
of the metrics.
Be aware that before the end of an instrumented application, there must be a call to
the close() method of the oracle.sqlj.runtime.sqlmonitor.SQLMonitor class, such
as in the following example (which also uses the Oracle class close() method to
close the connection context):
try
{
Oracle.close();
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oracle.sqlj.runtime.sqlmonitor.SQLMonitor.close();
}
catch( Throwable e ) { ... }
Note the following terms:

• The application_name is the name of the application according to the SQLJ
-instrument option, or defaultApp by default.
• If a sensor is associated with a package, then the item module is the package
name. The setting *TopLevel* is used if the package name is empty.
• If a sensor is associated with a class, then class is the class name.
• If a sensor is associated with a SQL statement, then linenum denotes the line
number of the SQL statement in the SQLJ program being instrumented. If multiple
SQL statements appear in the same line, then their starting column positions are
used to distinguish them. For example, a linenum value of 8.13 indicates that 8 is
the line number and 13 is the column number.
The following sensors and associated metrics are typically of particular interest:
• Sensor name: ContextType
/SQLJ/application_name/module/class/linenum/ContextType
Metrics:
– value: A string indicating the connection context type
• Sensor name: SQLString
/SQLJ/application_name/module/class/linenum/SQLString
Metrics:
– value: A string consisting of the SQL statement
This is the exact string that is passed to JDBC, including any transformations
made from the original #sql statement.
• Sensor name: Execute
/SQLJ/application_name/module/class/linenum/Execute
Metrics:
– time: The total time, in milliseconds, of all the executions of the JDBC
execute() method for this statement
If the statement executes five times, for example, then time would be the total
time spent in the execute() method for the five executions.
– completed: The number of executions completed (such as 5)
– minTime: The shortest time of any single execution
– maxTime: The longest time of any single execution
– avg: The average execution time, which is time divided by completed
– active: The number of threads executing the statement at the end of program
execution, typically 0.
– maxActive: The maximum number of threads that executed the statement
during program execution
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To measure the execution time of a JDBC statement, the clock is started

immediately before the statement is executed and stopped when a result set is
obtained or the statement otherwise finishes executing, or when an exception is
caught.
• Sensor name: ServerExecute
/SQLJ/application_name/module/class/linenum/ServerExecute
Metrics:
– value: The total execution time in the server, in milliseconds, for all executions
of this SQL statement
– count: The number of executions completed
– minValue: The shortest time of any single execution
– maxValue: The longest time of any single execution
• Sensor name: ServerFetch
/SQLJ/application_name/module/class/linenum/ServerFetch
Metrics:
– value: The total fetch time in the server, in milliseconds, for all executions of
this SQL statement
• Sensor name: ServerParse
/SQLJ/application_name/module/class/linenum/ServerParse
Metrics:
– value: The total time spent parsing the SQL statement in the server, in
milliseconds, for all executions of this SQL statement
• Sensor name: Next
/SQLJ/application_name/module/class/linenum/Next
Metrics:
– time: The total time, in milliseconds, spent in the next() method of the result
set iterator for all executions of this SQL statement
– completed: The number of executions completed (such as 5)
– minTime: The shortest time of any single execution
– maxTime: The longest time of any single execution
– avg: The average execution time, which is time divided by count.
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– active: The number of threads executing the statement at the end of program
execution, typically 0.
– maxActive: The maximum number of threads that executed the statement
during program execution
11.3.5 SQLJ DMS Examples

Following is a sample command line (a single wraparound line) to instrument the SQLJ
program ExprDemo.sqlj:
% sqlj -dir=. -instrument=a.b.c/app -components=all
-user=HR -url=jdbc:oracle:oci:@ ExprDemo.sqlj
Password: password
Note:
Ensure that dms.jar is in your classpath.
This command results in generation of the following files:

• ./a/b/c/ExprDemo.java (due to the -dir option setting and because package
a.b.c is declared in ExprDemo.sqlj)
• ./a/b/c/app.properties (due to the -instrument option setting)
Sample SQLJ DMS Properties File

The following is sample content for app.properties. This assumes you edited the file
after SQLJ created it, given that some of the settings here are nondefault.
sqlmonitor.components=all
sqlmonitor.monitorcomp=all
sqlmonitor.dms=true
sqlmonitor.servertracing=true
sqlmonitor.sysurl=jdbc:oracle:oci:@
sqlmonitor.sysuser=HR
sqlmonitor.syspassword=hr
sqlmonitor.dumpfile=a/b/c/app.mtr
Note:
If you run the SQLJ translator again, then app.properties is overwritten and
you will lose any changes you made.
Sample Statistics
The sqlmonitor.dms=true setting specifies that monitoring statistics are to be
delivered to DMS. Given the sqlmonitor.dumpfile value, the DMS tool writes the
statistics to the ./a/b/c/app.mtr file when you compile and run the program.
To examine statistics for a particular code sample, here is a segment of

ExprDemo.sqlj:
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#sql
{
DECLARE
n NUMBER;
s NUMBER;
BEGIN
n := 0;
s := 0;
WHILE n < 100 LOOP
n := n + 1;
s := s + :IN (indx++);
END LOOP;
:OUT total := s;
END;
};
And here is a segment of statistics from app.mtr, relating to the preceding code
example and showing the execution time and server execution times:
SQLString.value: DECLARE n NUMBER; s NUMBER;
BEGIN n := 0; s := 0; WHILE n < 100 LOOP
n := n + 1;
s := s + :1 ;
END LOOP; :2 := s; END; statement SQL string
ServerExecute.maxValue: 20.0 server_execute_time
ServerExecute.minValue: 20.0 server_execute_time
ServerExecute.count: 0 ops
ServerExecute.value: 20.0 server execute time
ServerFetch.maxValue: 0.0 server_fetch_time
ServerFetch.minValue: 0.0 server_fetch_time
ServerFetch.count: 0 ops
ServerFetch.value: 0.0 server fetch time
ServerParse.maxValue: 0.0 server_parse_time
ServerParse.minValue: 0.0 server_parse_time
ServerParse.count: 0 ops
ServerParse.value: 0.0 server parse time
193.5
ContextType.value: class sqlj.runtime.ref.DefaultContext
statement connection context
Execute.maxActive: 1 threads
Execute.active: 0 threads
Execute.avg: 37.0 msecs
Execute.maxTime: 37 msecs
Execute.minTime: 37 msecs
Execute.completed: 1 ops
Execute.time: 37 msecs
These statistics indicate that the total execution time at the JDBC client was 37
milliseconds (in one execution), while the execution time in the server was 20
milliseconds.
Sample Statistics for Iterators

ExprDemo.sqlj also defines and executes an iterator type, Iter, as follows:
#sql public static iterator Iter(String ename);
....
Iter iter;
#sql iter = { select first_name from employees};
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Chapter 11
while (iter.next())
{
System.out.println(iter.ename());
}
For iterators, DMS collects the execution time for the next() operation. Here is a
sample DMS result for the iterator type Iter:
Iter
Next.time: 5 msecs
This shows that the total time spent on the next() operation while iterating through the
Iter instance was 5 milliseconds.
Sample Statistics for Connection Contexts

The #sql statements in ExprDemo.sqlj use the default connection context. For the
DefaultContext instance used throughout the program, DMS returns the following
statistics:
class_sqlj.runtime.ref.DefaultContext
StmtCacheSize.value: 5 statement cache size
StmtsExecuted.count: 7 ops
StmtsCacheExecuted.count: 7 ops
This shows that the context has a statement cache size of five statements. Altogether,
seven SQL statements are executed.
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A
Customization and Specialized
Customizers
Profiles and profile customization are introduced in "SQLJ Profiles". This appendix
presents more technical detail and discusses customizer options and how to use
customizers other than the default Oracle customizer.
There is also discussion of Oracle specialized customizers, particularly the
SQLCheckerCustomizer for semantics-checking profiles, and the AuditorInstaller for
installing auditors for debugging.
The following topics are covered:
• More About Profiles
• More About Profile Customization
• Customization Options and Choosing a Customizer
• JAR Files for Profiles
• SQLCheckerCustomizer for Profile Semantics-Checking
• AuditorInstaller Customizer for Debugging
Note:
If you use the default Oracle-specific code generation (-codegen=oracle),
the discussion in this appendix does not pertain to your application.
A.1 More About Profiles

SQLJ profiles contain information about your embedded SQL operations, with a
separate profile being created for each connection context class that your application
uses. Profiles are created during the SQLJ translator code generation phase and
customized during the customization phase. Customization enables your application
to use vendor-specific database features. Separating these vendor-specific operations
into your profiles enables the rest of your generated code to remain generic.
Each profile contains a series of entries for the SQLJ statements that use the relevant
connection context class, where each entry corresponds to one SQL operation in your
application.
Profiles exist as serialized objects stored in resource files packaged with your
application. Because of this, profiles can be loaded, read, and modified (added to
or recustomized) at any time. When profiles are customized, information is only
added, never removed. Multiple customizations can be made without losing preceding
customizations, so that your application maintains the capability to run in multiple
environments. This is known as binary portability.
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Appendix A
More About Profiles
For profiles to have binary portability, SQLJ industry-standard requirements have been
met in the Oracle SQLJ implementation.
A.1.1 Creation of a Profile During Code Generation

During code generation, the translator creates each profile as follows:
1. It creates a profile object as an instance of the sqlj.runtime.profile.Profile
class.
2. It inserts information about your embedded SQL operations into the profile object,
for SQLJ statements that use the relevant connection context class.
3. It serializes the profile object into a Java resource file, referred to as a profile file,
with a .ser file name extension.
Note:
The Oracle SQLJ implementation provides an option to have the translator
automatically convert these .ser files to .class files. The.ser files are
not supported by some browsers, and can be cumbersome when loading
translated applications into the server. However, this prevents any further
customization of the profile.
As discussed in "Code Generation", profile file names for application Foo are of the
form:
Foo_SJProfilen.ser
SQLJ generates Foo_SJProfile0.ser, Foo_SJProfile1.ser, and so on, as needed,

depending on how many connection context classes you use in your code. Or,
if the -ser2class option is enabled, then SQLJ generates Foo_SJProfile0.class,
Foo_SJProfile1.class, and so on.
Each profile has a getConnectedProfile() method that is called during SQLJ runtime.
This method returns something equivalent to a JDBC Connection object, but with
added functionality. This is further discussed in "Functionality of a Customized Profile
at Run Time".
Note:
Referring to a "profile object" indicates that the profile is in its original
nonserialized state. Referring to a "profile file" indicates that the profile is
in its serialized state in a .ser file.
A.1.2 Sample Profile Entry

Following is a sample SQLJ executable statement with the profile entry that would
result. For simplicity, the profile entry is presented as plain text with irrelevant portions
omitted.
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Appendix A
More About Profile Customization
Note that in the profile entry, the host variable is replaced by JDBC syntax (the
question mark).
A.1.2.1 SQLJ Executable Statement

Presume the following declaration:
#sql iterator Iter (double sal, String ename);
And presume the following executable statements:

String empname = 'Smith';
Iter it;
...
#sql it = { SELECT first_name, salary FROM employees WHERE first_name
= :empname };
A.1.2.2 Corresponding SQLJ Profile Entry

=================================================================
...
#sql { SELECT first_name, salary FROM employees WHERE first_name = ? };
...
PREPARED_STATEMENT executed through EXECUTE_QUERY
role is QUERY
descriptor is null
contains one parameter
1. mode: IN, java type: java.lang.String (java.lang.String),
sql type: VARCHAR, name: ename, ...
result set type is NAMED_RESULT
result set name is Iter
contains 2 result columns
1. mode: OUT, java type: double (double),
sql type: DOUBLE, name: sal, ...
2. mode: OUT, java type: java.lang.String (java.lang.String),
sql type: VARCHAR, name: ename, ...
=================================================================
Note:
This profile entry is presented here as text for convenience only; profiles are
not actually in text format. They can be printed as text, however, using the
SQLJ -P-print option, as discussed in "Overview of Customizer Harness
Options".
A.2 More About Profile Customization

When using ISO SQLJ code, running the sqlj script on a SQLJ source file
includes an automatic customization process, where each profile created during
the code generation phase is customized for use with your particular database.
The default customizer is Oracle customizer, oracle.sqlj.runtime.OraCustomizer,
which optimizes your profiles to use type extensions and performance enhancements
specific to Oracle Database 12c Release 2 (12.2).
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Appendix A
You can also run the sqlj script to customize profiles created previously. On the SQLJ
command line, you can specify .ser files individually, JAR files containing .ser files, or
both.
Note:
• Whenever you use the default Oracle customizer during translation, your
application will require Oracle SQLJ run time and an Oracle JDBC driver
when it runs, even if you do not use Oracle extensions in your code.
• If an application has no customizations, or none suitable for the
connection, then the generic SQLJ run time is used.
• You can run SQLJ to process .sqlj and .java files (for translation,
compilation, and customization) or to process .ser and .jar files (for
customization only), but not both categories at once.
A.2.1 Overview of the Customizer Harness and Customizers

Regardless of whether you use Oracle customizer or an alternative customizer,
SQLJ uses a front-end customization utility known as the customizer harness in
accomplishing your customizations.
When you run SQLJ, you can specify customization options for the customizer
harness (for general customization settings that apply to any customizer you use) and
for your customizer (for settings used by the particular customizer). In either case, you
can specify these options either on the command line or in a properties file. This is
discussed in "Customization Options and Choosing a Customizer".
A customizer is required to be a JavaBeans component adhering to the
standard JavaBeans API to expose its properties, and must implement
the sqlj.runtime.profile.util.ProfileCustomizer interface, which specifies a
customize() method. For each profile to be customized, the customizer harness calls
the customize() method of the customizer object.
Oracle customizer meets the preceding requirements and is defined in the

oracle.sqlj.runtime.OraCustomizer class.
A.2.2 Steps in the Customization Process

The SQLJ customization process during translation consists of the following steps, as
applicable, either during the customization stage of an end-to-end SQLJ run, or when
you run SQLJ to customize existing profiles only:
1. SQLJ instantiates and invokes the customizer harness and passes it any general
customization options you specified.
2. The customizer harness instantiates the customizer you are using and passes it
any customizer-specific options you specified.
3. When you run SQLJ for customization only, specifying one or more JAR files on
the command line, the customizer harness discovers and extracts the profile files
within these JAR files.
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Appendix A
4. The customizer harness deserializes each profile file into a profile object (.ser
files automatically created during an end-to-end SQLJ run, .ser files specified on
the command line for customization only, or .ser files extracted from JAR files
specified on the command line for customization only).
5. If the customizer you use requires a database connection, the customizer harness
establishes that connection.
6. For each profile, the harness calls the customize() method of the customizer
object instantiated in step 2 (customizers used with SQLJ must have a
customize() method).
7. For each profile, the customize() method typically creates and registers a profile
customization within the profile. This depends on the intended functionality of
the customizer, however. Some might have a specialized purpose that does not
require a customization to be created and registered in this way.
8. The customizer harness reserializes each profile and puts it back into a .ser file.
9. When you run SQLJ for customization only, specifying one or more JAR files
on the command line, the customizer harness recreates the JAR contents,
inserting each customized .ser file to replace the original corresponding
uncustomized .ser file.
Note:
• If an error occurs during customization of a profile, the original .ser file is

not replaced.
• If an error occurs during customization of any profile in a JAR file, the
original JAR file is not replaced.
• SQLJ can run only one customizer at a time. If you want to accomplish
multiple customizations on a single profile, you must run SQLJ multiple
times. For the additional customizations, enter the profile name directly
on the SQLJ command line.
A.2.3 Creation and Registration of a Profile Customization

When the harness calls the customize() method to customize a profile, it passes in
the profile object, a SQLJ connection context object (if you are using a customizer
that requires a connection), and an error log object (which is used in logging error
messages during the customization).
The same error log object is used for all customizations throughout a single running
of SQLJ, but its use is transparent. The customizer harness reads messages written
to the error log object and reports them in real-time to the standard output device
(whatever SQLJ uses, typically your screen).
Recall that each profile has a set of entries, where each entry corresponds to a SQL
operation. (These would be the SQL operations in your application that use instances
of the connection context class associated with this profile.)
A customize() method implements special processing on these entries. It could be as
simple as checking each entry to verify its syntax, or it could be more complicated,
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Appendix A
such as creating new entries that are equivalent to the original entries but are modified
to use features of your particular database.
Note:
• Any customize() processing of profile entries does not alter the original
entries.
• Customizing your profiles for use in a particular environment does not
prevent your application from running in a different environment. You can
customize a profile multiple times for use in multiple environments, and
these customizations will not interfere with each other.
A.2.4 Customization Error and Status Messages

The customizer harness outputs error and status messages in much the same way as
the SQLJ translator, outputting them to the same output device. None of the warnings
regarding customization are suppressible, however.
Error messages reported by the customizer harness fall into four categories:
• Unrecognized or illegal option
• Connection instantiation error
• Profile instantiation error
• Customizer instantiation error
Status messages reported by the customizer harness during customization enable
you to determine whether a profile was successfully customized. They fall into three
categories:
• Profile modification status
• JAR file modification status
• Name of backup file created (if the customizer harness backup option is enabled)
Additional customizer-specific errors and warnings might be reported by the
customize() method of the particular customizer.
During customization, the profile customizer writes messages to its error log, and the
customizer harness reads the log contents in real-time and outputs these messages
to the SQLJ output device, along with any other harness output. You never have to
access error log contents directly.
A.2.5 Functionality of a Customized Profile at Run Time

A customized profile is a static member of the connection context class with which
it is associated. For each SQLJ statement in your application, the SQLJ run time
determines the connection context class and instance associated with that statement,
then uses the customized profile of the connection context class, together with the
underlying JDBC connection of the particular connection context instance, to create a
connected profile. This connected profile is the vehicle that the SQLJ run time uses in
applying vendor-specific features to the execution of your SQLJ application.
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Appendix A
Customization Options and Choosing a Customizer
A.3 Customization Options and Choosing a Customizer

This section discusses options for profile customization, which fall into three
categories:
• Options you specify to the customizer harness, which apply to whatever
customizer you use.
This includes general options, connection options, and options that invoke
specialized customizers.
• Customizer-specific options you specify to your customizer through the customizer
harness.
• SQLJ options, which determine basic aspects of customization, such as whether
to customize at all and which customizer to use.
All categories of options are specified through the SQLJ command line or properties
files.
The following topics are included in this section:
• Overview of Customizer Harness Options
• General Customizer Harness Options
• Customizer Harness Options for Connections
• Customizer Harness Options that Invoke Specialized Customizers
• Overview of Customizer-Specific Options
• Oracle Customizer Options
• SQLJ Translator Options for Profile Customization
To choose a customizer other than the default Oracle customizer, you can use either
the customizer harness customizer option (discussed in "Overview of Customizer
Harness Options") or the SQLJ -default-customizer option (discussed in "SQLJ
Translator Options for Profile Customization").
A.3.1 Overview of Customizer Harness Options

The customizer harness provided with the Oracle SQLJ implementation offers a
number of options that are not specific to a particular customizer. The harness uses
these options in its front-end coordination of the customization process.
A.3.1.1 Syntax for Customizer Harness Options

Customizer harness option settings on the SQLJ command line have the following
syntax:
-P-option=value
Alternatively, in a SQLJ properties file:

profile.option=value
Enable boolean options (flags) either with:

-P-option
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Appendix A
or:
-P-option=true
Boolean options are disabled by default, but you can explicitly disable them with:
-P-option=false
A.3.1.2 Options Supported by the Customizer Harness

The customizer harness supports the following general options:
• backup: Save a backup copy of the profile before customizing it.
• context: Limit customizations to profiles associated with the listed connection
context classes.
• customizer: Specify the customizer to use.
• digests: Specify digests for JAR file manifests (relevant only if specifying JAR
files to customize).
• help: Display customizer options (specified only in SQLJ command line).
• verbose: Display status messages during customization.
The customizer harness supports the following options for customizer database
connections. Currently, these are used by Oracle customizer if you enable its optcols
option for column definitions (for performance optimization). In addition, they are used
by the SQLCheckerCustomizer if you use this specialized customizer to perform online
semantics-checking on profiles.
• user: Specify the user name for the connection used in this customization.
• password: Specify the password for the connection used in this customization.
• url: Specify the URL for the connection used in this customization.
• driver: Specify the JDBC driver for the connection used in this customization.
For information about the Oracle customizer optcols flag, see "Oracle Customizer
Column Definition Option (optcols)". For information about the SQLCheckerCustomizer,
see "SQLCheckerCustomizer for Profile Semantics-Checking".
The following commands function as customizer harness options, but are implemented
through specialized customizers provided with the Oracle SQLJ implementation.
• debug: Insert debugging information into the specified profiles, to be output at run
time. This is a shortcut to invoke the Oracle SQLJ AuditorInstaller, which is
described in "AuditorInstaller Customizer for Debugging".
• print: Output the contents of the specified profiles, in text format.
• verify: Perform semantics-checking on a profile that was produced during a
previous execution of the SQLJ translator (equivalent to semantics-checking
performed on source code during translation). This is a shortcut to invoke Oracle
SQLJ SQLCheckerCustomizer, which is described in "SQLCheckerCustomizer for
Profile Semantics-Checking".
A.3.2 General Customizer Harness Options

This section describes general options supported by the customizer harness.
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Appendix A
A.3.2.1 Profile Backup Option (backup)

Use the backup flag to instruct the harness to save a backup copy of each .jar file
and standalone .ser file before replacing the original. (Separate backups of .ser files
that are within .jar files are not necessary.)
Backup file names are given the extension .bakn, where n indicates digits used as
necessary where there are similarly named files. For each backup file created, an
informational message is issued.
If an error occurs during customization of a standalone .ser file, then the original .ser
file is not replaced and no backup is created. Similarly, if an error occurs during
customization of any .ser file within a JAR file, then the original JAR file is not
replaced and no backup is created.
The command-line syntax for this option is:
-P-backup<=true|false>
Command-line example is:

-P-backup
Properties file syntax is:

profile.backup<=true|false>
Default value is:

false
A.3.2.2 Customization Connection Context Option (context)

Use the context option to limit customizations to profiles that correspond to the
specified connection context classes. Fully qualify the class names and use a comma-
delimited list to specify multiple classes. For example:
-P-context=sqlj.runtime.ref.DefaultContext,foo.bar.MyCtxtClass
There must be no space on either side of the comma.

If this option is not specified, then all profiles are customized, regardless of their
associated connection context classes.
Command-line syntax is:
-P-context=ctx_class1<,ctx_class2,...>

-P-context=foo.bar.MyCtxtClass

profile.context=ctx_class1<,ctx_class2,...>
Properties file example is:

profile.context=foo.bar.MyCtxtClass
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Appendix A
A.3.2.3 Customizer Option (customizer)

Use the customizer option to specify which customizer to use. Fully qualify the class
name, such as in the following example:
-P-customizer=oracle.sqlj.runtime.util.OraCustomizer
If you do not set this option, then SQLJ will use the customizer specified in the SQLJ
-default-customizer option. Unless set otherwise, this is the following:

-P-customizer=customizer_class

-P-customizer=a.b.c.MyCustomizer

profile.customizer=customizer_class

profile.customizer=a.b.c.MyCustomizer
Default value is:

None
A.3.2.4 Customization JAR File Digests Option (digests)

When a JAR file is produced, the JAR utility can optionally include one or more digests
for each entry, based on one or more specified algorithms, so that the integrity of the
JAR file entries can later be verified. Digests are similar conceptually to checksums,
for readers familiar with those.
If you are customizing profiles in a JAR file and want the JAR utility to add new digests
(or update existing digests) when the JAR file is updated, use the digests option to
specify a comma-delimited list of one or more algorithms. These are the algorithms
that the JAR utility will use in creating the digests for each entry. The JAR utility
produces one digest for each algorithm for each JAR file entry in the JAR manifest file.
Specify algorithms as follows:
-P-digests=SHA,MD5

In this example, there will be two digests for each entry in the JAR manifest file: an SHA
digest and an MD5 digest.
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Appendix A
Note:
Visit the Sun site more information about JAR manifest file.
For information about JAR files and the JAR utility, see one of the following Web sites:
http://www.javasoft.com/products/jdk/1.2/docs/guide/jar/index.html

-P-digests=algo1<,algo2,...>

-P-digests=SHA,MD5

profile.digests=algo1<,algo2,...>

profile.digests=SHA,MD5
Default value is:

SHA,MD5
A.3.2.5 Customization Help Option (help)

Use the help option to display the option lists of the customizer harness and the
default customizer or a specified customizer. For the harness and Oracle customizer,
this includes a brief description and the current setting of each option.
Display the option lists for the harness and default customizer as follows (where the
default customizer is Oracle customizer or whatever you have specified in the SQLJ
-default-customizer option):
-P-help
Use the help option in conjunction with the customizer option to display the option list
of a particular customizer, as follows:
-P-help -P-customizer=sqlj.runtime.profile.util.AuditorInstaller
Note:
• You can use the -P-help option on the SQLJ command line only, not in a
SQLJ properties file.
• No customizations are performed if the -P-help flag is enabled, even if
you specify profiles to customize on the command line.
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Appendix A
-P-help <-P-customizer=customizer_class>

-P-help

NA

NA
Default value is:

None
A.3.2.6 Customization Verbose Option (verbose)

Use the verbose flag to instruct the harness to display status messages during
customizations. These messages are written to the standard output device, wherever
SQLJ writes its other messages.
-P-verbose<=true|false>

-P-verbose

profile.verbose<=true|false>

profile.verbose
Default value is:

false
A.3.3 Customizer Harness Options for Connections

This section describes connection options supported by the customizer harness.
These are used as follows:
• Oracle customizer uses database connections only for column definitions. If you
do not enable Oracle customizer optcols option, then there is no need to set the
customizer harness user, password, url, and driver options.
• The SQLCheckerCustomizer, a specialized customizer that performs semantics-
checking on profiles, uses the customizer harness user, password, url, and
driver settings for online checking.
Use -P-verify on the SQLJ command line to invoke this customizer.
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Appendix A
Note:
Do not confuse the customizer harness user, password, url, and driver
options with the translator options of the same names, which are for
semantics-checking during the translation step. However, the translator
settings are passed to the customizer for convenience, in case customization
is to use the same connection as translation. Override these initial settings
through the customizer harness options if you wish.
A.3.3.1 Customization User Option (user)

Set the user option to specify a database schema if your customizer uses database
connections.
In addition to specifying the schema, you can optionally specify the password, URL, or
both in your user option setting. The password is preceded by a forward-slash (/), and
the URL is preceded by an "at" sign (@), as in the following examples:
-P-user=HR/hr
-P-user=HR@jdbc:oracle:oci:@
-P-user=HR/hr@jdbc:oracle:oci:@
Note:
When you use column definitions (optcols option), the user setting for the
SQLJ translator is forwarded to the profile customizer as well, but you can
use the customizer user option to override the translator setting.

-P-user=username</password><@url>
Command-line examples is:

-P-user=HR
-P-user=HR/password
-P-user=HR/password@jdbc:oracle:oci:@

profile.user=username</password><@url>
Properties file examples is:

profile.user=HR
profile.user=HR/hr
profile.user=HR/hr@jdbc:oracle:oci:@
Default value is:

null
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Appendix A
A.3.3.2 Customization Password Option (password)

Use the password option if your customizer uses database connections.
The password can also be set with the user option, as described in "Customization
User Option (user)".
Note:
When you use column definitions (optcols option), the password setting for
the SQLJ translator is forwarded to the profile customizer as well, but you
can use the customizer password option to override the translator setting.

-P-password=password

-P-password=password

profile.password=password

profile.password=password
Default value is:

null
A.3.3.3 Customization URL Option (url)

Use the url option if your customizer uses database connections.
The URL can also be set with the user option, as described in "Customization User
Option (user)".
Note:
When you use column definitions (optcols option), the URL setting for the
SQLJ translator is forwarded to the profile customizer as well, but you can
use the customizer url option to override the translator setting.

-P-url=url
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Appendix A
-P-url=jdbc:oracle:oci:@

profile.url=url

profile.url=jdbc:oracle:oci:@
Default value is:

jdbc:oracle:oci:@
A.3.3.4 Customization JDBC Driver Option (driver)

Use the driver option to register a comma-delimited list of JDBC driver classes if your
customizer uses database connections. For example:
-P-driver=sun.jdbc.odbc.JdbcOdbcDriver,oracle.jdbc.OracleDriver

-P-driver=dvr_class1<,dvr_class2,...>

-P-driver=sun.jdbc.odbc.JdbcOdbcDriver

profile.driver=dvr_class1<,dvr_class2,...>

profile.driver=sun.jdbc.odbc.JdbcOdbcDriver
Default value is:

oracle.jdbc.OracleDriver
A.3.4 Customizer Harness Options that Invoke Specialized

Customizers
The customizer harness supports the following options that invoke specialized
customizers:
• debug: This invokes the AuditorInstaller customizer, used in debugging.
• print: This invokes a customizer that prints a text version of a profile.
• verify: This invokes the SQLCheckerCustomizer customizer, which performs
semantics-checking on a profile.
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Appendix A
Note:
Because each of these options invokes a customizer, and only one
customizer can run in a single execution of SQLJ, you cannot perform any
other customization when you use any of these options.
You also cannot use more than one of print, debug, or verify
simultaneously.
A.3.4.1 Specialized Customizer: Profile Debug Option (debug)

The debug option runs a specialized customizer, called the AuditorInstaller, that
inserts debugging statements into profiles. Use this option in conjunction with a SQLJ
command line file list to insert debugging statements into the specified profiles. These
profiles must already be customized from a previous SQLJ run.
For detailed information about this customizer, including additional options that it
supports, see "AuditorInstaller Customizer for Debugging".
The debugging statements will execute during SQLJ run time (when someone runs
your application), displaying a trace of method calls and values returned.
Following are examples of how to specify the debug option:
% sqlj -P-debug Foo_SJProfile0.ser Bar_SJProfile0.ser
% sqlj -P-debug *.ser

sqlj -P-debug profile_list

sqlj -P-debug Foo_SJProfile*.ser

profile.debug
(Also specify profiles in the SQLJ file list.)

profile.debug
Default value is:

NA
A.3.4.2 Specialized Customizer: Profile Print Option (print)

The print option runs a specialized customizer that prints profiles in text format. Use
this option in conjunction with a SQLJ command line file list to output the contents of
one or more specified profiles. The output goes to the standard SQLJ output device,
typically the user screen. For example:
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Appendix A
% sqlj -P-print Foo_SJProfile0.ser Bar_SJProfile0.ser
Use the following command, if you want to see all the customizer options:
% sqlj -P-print *.ser
The output of the preceding command is like the following:

printing contents of profile Sample_SJProfile0
created 1154609279331 (8/3/06 5:47 AM)
associated context is Mycontext1
profile loader is sqlj.runtime.profile.DefaultLoader@12a3793
contains one customization
OracleCustomization Options :
Version is :2300
Cstmtcache :5
Ccompat :false
Cforce :false
Coptcols :false
Coptparams :false
Coptparamdefaults:null
CshowSQL :false
Csummary :false
CuserSQL :true
#sql { SELECT a FROM test WHERE name= ? }

setFixedchar is enabled
Ncharconv is disabled
#sql { commit }
setFixedchar is disabled
Ncharconv is disabled
………

sqlj -P-print profile_list

sqlj -P-print Foo_SJProfile*.ser

profile.print
(Also specify profiles in SQLJ file list.)

profile.print
Default value is:

NA
A.3.4.3 Specialized Customizer: Profile Semantics-Checking Option (verify)

The verify option runs a specialized customizer, called the SQLCheckerCustomizer,
that performs semantics-checking on a profile. This is equivalent to the semantics-
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Appendix A
checking that is performed on source code during translation. The profile will have
been created during a previous execution of the SQLJ translator.
This option is useful for checking semantics against the run-time database, after
deployment, and after the source code may no longer be available.
For detailed information about this customizer, including additional options that it
supports, see "SQLCheckerCustomizer for Profile Semantics-Checking".
Note:
For online semantics-checking of the profile, you must also use the
customizer harness user, password, and url options.
Following are examples of how to specify the verify option. Both of these examples
use the SQLCheckerCustomizer default semantics-checker, which employs online
checking through the specified database connection. (The first is a single wraparound
command.)
% sqlj -P-verify -P-user=HR -P-url=jdbc:oracle:oci:@ Foo_SJProfile0.ser
Bar_SJProfile0.ser
Password: password
% sqlj -P-verify -P-user=HR -P-url=jdbc:oracle:oci:@ *.ser

Password: password

sqlj -P-verify <conn params> profile_list

sqlj -P-verify <conn params> Foo_SJProfile*.ser

profile.verify
(You must also specify profiles, and typically customizer harness connection options,
in the SQLJ command line.)
profile.verify
Default value is:

NA
A.3.5 Overview of Customizer-Specific Options

You can set customizer-specific options, such as options for Oracle customizer, on
the SQLJ command line or in a SQLJ properties file. The syntax is similar to that for
setting customizer harness options.
Set a customizer option on the SQLJ command line by preceding it with:
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Appendix A
-P-C
Alternatively, you can set it in a SQLJ properties file by preceding it with:

profile.C
The remainder of this section discusses features of Oracle customizer, which supports
several options. Most of these options are boolean and are enabled as follows:
-P-Coption
or:
-P-Coption=true
Boolean options are disabled by default, but you can explicitly disable them with:
-P-Coption=false
Numeric or string options are set similarly:

-P-Coption=value
A.3.6 Oracle Customizer Options

This section describes options that are specific to Oracle customizer, beginning with
an overview of the options supported.
A.3.6.1 Options Supported by Oracle Customizer

Oracle customizer implements the following options:
• compat: Display version-compatibility information.
• force: Instruct the customizer to customize even if a valid customization already
exists.
• optcols: Enable iterator column type and size definitions to optimize performance.
• optparams: Enable parameter size definitions to optimize JDBC resource
allocation (used in conjunction with optparamdefaults).
• optparamdefaults: Set parameter size defaults for particular data types (used in
conjunction with optparams).
• fixedchar: Enable CHAR comparisons with blank padding for WHERE clauses.
• showSQL: Display SQL statement transformations.
• stmtcache: Set the statement cache size (the number of statements that can be
cached for each connection during run time) for performance optimization, or set it
to zero to disable statement caching.
• summary: Display a summary of Oracle features used in your application.
Any output displayed by these options is written to the standard output device,
wherever SQLJ writes its other messages.
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Appendix A
A.3.6.2 Oracle Customizer Version Compatibility Option (compat)

Use the compat flag to instruct Oracle customizer to display information about
compatibility of your application with different versions of Oracle Database and Oracle
JDBC drivers. This can be accomplished either during a full SQLJ translation run or on
profiles previously created.
For example, to see compatibility output when translating and customizing the
application MyApp:
% sqlj <...SQLJ options...> -P-Ccompat MyApp.sqlj
In this example, the MyApp profiles will be created, customized, and checked for
compatibility in a single running of SQLJ.
To see compatibility output for MyApp profiles previously created:
% sqlj <...SQLJ options...> -P-Ccompat MyApp_SJProfile*.ser
In this example, the MyApp profiles were created (and possibly customized) in a
previous running of SQLJ and will be customized (if needed) and checked for
compatibility in the above running of SQLJ.
Following are two output samples from a -P-Ccompat setting when using the default
Oracle customizer. The first example indicates that the application can be used with all
Oracle JDBC driver versions:
MyApp_SJProfile0.ser: Info: compatible with all Oracle JDBC drivers
This second example indicates that the application can be used only with the JDBC
implementation from an Oracle 8.1.x or later release:
MyApp_SJProfile0.ser: Info: compatible with Oracle 8.1 or later JDBC driver
Note:
If customization does not take place because a valid previous customization
is detected, the compat option reports compatibility regardless.

-P-Ccompat<=true|false>

-P-Ccompat

profile.Ccompat<=true|false>

profile.Ccompat
Default value is:
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Appendix A
false
A.3.6.3 Oracle Customizer Force Option (force)

Use the force flag to instruct Oracle customizer to force the customization of a given
profile (specified on the command line) even if a valid customization already exists in
that profile. For example:
% sqlj -P-Cforce MyApp_SJProfile*.ser
This will customize all the MyApp profiles, regardless of whether they have already
been customized. Otherwise, by default, Oracle customizer will not reinstall over a
previously existing customization unless the previous one had been installed with an
older version of the customizer.
-P-Cforce<=true|false>

-P-Cforce

profile.Cforce<=true|false>

profile.Cforce
Default value is:

false
A.3.6.4 Oracle Customizer Column Definition Option (optcols)

Use the optcols flag to instruct Oracle customizer to determine types and sizes of
iterator or result set columns and add this information to the profile. This enables the
SQLJ run time to automatically register the columns with Oracle JDBC driver when
your application runs, saving round trips to Oracle depending on the particular driver
implementation. Specifically, this is effective for the Thin driver and positional iterators.
For an overview of column definitions, see "Column Definitions".
An error will be generated if you enable Oracle customizer optcols option without
setting the user name, password, and URL for a database connection. You can
accomplish this through the translator -user, -password, and -url options, which are
forwarded to the customizer during ISO standard code generation, or directly through
the customizer user, password, and url options.
The customizer does not have to connect to the same schema or even the same
database that your application will connect to at run time, but the relevant columns will
have to be in the same order and of identical types and sizes to avoid run-time errors.
For information about the customizer harness connection options, see the user,
password, url, and driver sections under "Overview of Customizer Harness Options".
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Appendix A
Note:
You can use the SQLJ translator -optcols option instead. This sets the
customizer option automatically. For Oracle-specific code generation, which
uses no profiles, you must use the translator option instead.
That section also has some additional conceptual information.
You can enable or disable the customizer optcols flag on the SQLJ command line or
-P-Coptcols
or:
-P-Coptcols=true
-P-Coptcols=false
Column definitions require the customizer to make a database connection to examine

columns of tables being queried, so the customizer harness user, password, and url
options must be set appropriately (as well as the customizer harness driver option if
you are not using the default OracleDriver class). For example:
% sqlj <...SQLJ options...> -P-user=HR@jdbc:oracle:oci:@ -P-Coptcols MyApp.sqlj
Password: password
Note that as with the SQLJ translator, you can optionally set the password and URL in
the user option instead of in the password and url options.
Alternatively, you can insert column definitions into a previously existing profile. In this
case you must also use the Oracle customizer force option to force a recustomization:
% sqlj -P-user=HR@jdbc:oracle:oci:@ -P-Cforce -P-Coptcols MyApp_SJProfile*.ser
Password: password
You also can insert column definitions into previously existing profiles in a JAR file:
% sqlj -P-user=HR@jdbc:oracle:oci:@ -P-Cforce -P-Coptcols MyAppProfiles.jar
Password: password
When you run Oracle customizer with its optcols flag enabled, either during
translation and creation of a new profile or during customization of an existing profile,
you can also enable the customizer harness verbose flag. This will instruct Oracle
customizer to display information about what iterators and result sets are being
processed and what their column type and size definitions are. For example:
% sqlj -P-user=HR@jdbc:oracle:oci:@ -P-verbose -P-Cforce -P-Coptcols MyApp_SJProfile*.ser
Password: password
For general information about the verbose flag, see that section under "Overview of
Customizer Harness Options".
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Appendix A
You can execute Oracle customizer with its summary flag enabled on an existing profile
to determine if column definitions have been added to that profile:
% sqlj -P-Csummary MyApp_SJProfile*.ser
For general information about the summary flag, see that section under "Overview of
Customizer-Specific Options".
-P-Coptcols<=true|false>

-P-Coptcols

profile.Coptcols<=true|false>

profile.Coptcols
Default value is:

false
A.3.6.5 Oracle Customizer Parameter Definition Option (optparams)

Use the optparams flag to enable parameter size definitions. If this flag is enabled,
SQLJ will register your input and output parameters (host variables) to optimize JDBC
resource allocations according to sizes you specify.
For an overview of parameter size definitions and a discussion of source code hints,
see "Parameter Size Definitions".
Note:
You can use the SQLJ translator -optparams option instead. This sets the
customizer option automatically. (And for Oracle-specific code generation,
which uses no profiles, you must use the translator option instead.)
That section also has some additional conceptual information.
You can enable or disable the optparams flag on the command line or in a SQLJ
properties file.
-P-Coptparams
or:
-P-Coptparams=true
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Appendix A
-P-Coptparams=false
Note:
Unlike the optcols option, the optparams option does not require a
database connection by the customizer, because you are providing the size
specifications yourself.
Following is a command-line example (omitting a setting for the optparamdefaults

option, which is discussed in the next section):
% sqlj <...SQLJ options...> -P-Coptparams -P-Coptparamdefaults=defaults_string MyApp.sqlj
Alternatively, to enable parameter size definitions for a previously existing profile:

% sqlj -P-Coptparams -P-Coptparamdefaults=defaults_string MyApp_SJProfile*.ser
You can also use previously existing profiles in a JAR file:

% sqlj -P-Coptparams -P-Coptparamdefaults=defaults_string MyAppProfiles.jar

-P-Coptparams<=true|false>

-P-Coptparams

profile.Coptparams<=true|false>

profile.Coptparams
Default value is:

false
A.3.6.6 Oracle Customizer Parameter Default Size Option (optparamdefaults)

If you enable the optparams option to set parameter sizes, use the optparamdefaults
option as desired to set default sizes for specified data types. If optparams is not
enabled, then any optparamdefaults setting is ignored.
For an overview of parameter size definitions and a discussion of source code hints,
see "Parameter Size Definitions".
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Appendix A
Note:
You can use the SQLJ translator -optparamdefaults option instead. This
sets the customizer option automatically. (And for Oracle-specific code
generation, which uses no profiles, you must use the translator option
instead.)
That section also has important additional conceptual and syntax
information. Functionality of the two options is equivalent.
You can set the optparamdefaults flag on the command line or in a SQLJ properties
file.
Set it on the command line as follows:
-P-Coptparamdefaults=datatype1(size1),datatype2(size2),...
Following is a command-line example, including the optparams setting as well:

% sqlj <..SQLJ options..> -P-Coptparams -P-Coptparamdefaults=CHAR_TYPE(50),RAW_TYPE(500),CHAR(10) MyApp.sqlj
Alternatively, you can specify parameter size defaults for a previously existing profile,
in which case you must also use the Oracle customizer force option to force a
recustomization:
% sqlj -P-Cforce -P-Coptparams -P-Coptparamdefaults=CHAR_TYPE(50),RAW_TYPE(500),CHAR(10) MyApp_SJProfile*.ser
You also can specify parameter size defaults for previously existing profiles in a JAR
file:
% sqlj -P-Cforce -P-Coptparams -P-Coptparamdefaults=CHAR_TYPE(50),RAW_TYPE(500),CHAR(10) MyAppProfiles.jar
Note:
If at run time, the actual size exceeds the registered size of any parameter,
run-time errors will occur.

-P-Coptparamdefaults=defaults_string

-P-Coptparamdefaults=VAR%(50),LONG%(500),RAW_TYPE()

profile.Coptparamdefaults=defaults_string

profile.Coptparamdefaults=VAR%(50),LONG%(500),RAW_TYPE()
Default value is:

null
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Appendix A
A.3.6.7 Oracle Customizer CHAR Comparisons with Blank Padding (fixedchar)

Set this flag to true to account for blank padding in CHAR database columns when
binding character strings for WHERE clause comparisons. This way, for example,
"mystring" would compare positively against "mystring ".
Here is an example of Oracle customizer fixedchar usage:
% sqlj -P-Cfixedchar MyProgram.sqlj AnotherProg.java ...
Note:
• You can use the SQLJ translator -fixedchar option instead. This
sets the customizer option automatically. (And for Oracle-specific code
generation, which uses no profiles, you must use the translator option
instead.)
• If you also enable the Oracle customizer summary flag, the number of
usages of the Oracle setFixedCHAR() API (used behind the scenes
for fixedchar functionality) will be displayed. See "Oracle Customizer
Summary Option (summary)" for an example.

-P-Cfixedchar<=true|false>

-P-Cfixedchar

profile.Cfixedchar<=true|false>

profile.Cfixedchar
Default value is:

false
A.3.6.8 Oracle Customizer Show-SQL Option (showSQL)

Use the showSQL flag to display any SQL statement transformations performed
by Oracle customizer. Such transformations are necessary in cases where SQLJ
supports syntax that the database does not directly support.
To show SQL transformations when translating and customizing the application MyApp:
% sqlj <...SQLJ options...> -P-CshowSQL MyApp.sqlj
In this example, the MyApp profiles will be created and customized and their SQL
transformations displayed in a single running of SQLJ.
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Appendix A
To show SQL transformations when customizing MyApp profiles previously created:

% sqlj <...SQLJ options...> -P-CshowSQL MyApp_SJProfile*.ser
previous running of SQLJ and will be customized (if needed) and have their SQL
transformations displayed in the above running of SQLJ.
The showSQL output might include an entry such as this:
MyApp.sqlj:14: Info: <<<NEW SQL>>> #sql {BEGIN ? := VALUES(tkjsSET_f1); END};
in file MyApp, line 14, we had:
#sql {set :v1= VALUES(tkjsSET_f1) };
During customization, Oracle customizer replaces the SET statement with an

equivalent PL/SQL block.
Note:
is detected, the showSQL option shows SQL transformations regardless.

-P-CshowSQL<=true|false>

-P-CshowSQL

profile.CshowSQL<=true|false>

profile.CshowSQL
Default value is:

false
A.3.6.9 Oracle Customizer Statement Cache Size Option (stmtcache)

Use the Oracle customizer stmtcache option to set the statement cache size—the
number of statements that can be cached for each database connection as your
application runs—or to disable statement caching.
The default statement cache size is 5. For an overview of statement caching, see
"Statement Caching".
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Appendix A
Note:
With the default Oracle-specific code generation (-codegen=oracle), SQLJ
does not produce profiles and skips the customization step. In this case, use
connection context methods to control SQLJ statement caching.
You can set the statement cache size on the command line or in a properties file.
To use the command line to set the statement cache size to 15 (for example) for the
application MyApp:
% sqlj <...SQLJ options...> -P-Cstmtcache=15 MyApp.sqlj
To disable statement caching, set the cache size to 0:

% sqlj <...SQLJ options...> -P-Cstmtcache=0 MyApp.sqlj
You also can alter the statement cache size in an existing profile without retranslating
the application, but you must also use the Oracle customizer force option to force a
recustomization, as follows:
% sqlj -P-Cforce -P-Cstmtcache=15 MyApp_SJProfile0.ser
If you have multiple profiles, you can set their statement cache sizes individually by
running SQLJ separately for each profile, after you have translated your application:
Of course, you must determine which profile corresponds to each of your connection
context classes. This is determined as follows: profile 0 will correspond to the
connection context class used for the first executable statement in your application;
profile 1 will correspond to the connection context class used for the first executable
statement that does not use the first connection context class, and so on. You can
verify the correlation by using the customizer harness print option to examine each
profile.
-P-Cstmtcache=value

-P-Cstmtcache=10

profile.Cstmtcache=value

profile.Cstmtcache=10
Default value is:

5
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Appendix A
A.3.6.10 Oracle Customizer Summary Option (summary)

Use the summary flag to instruct Oracle customizer to display a summary of Oracle
features used in an application being translated, or in specified profile files. This is
useful in identifying features that would prevent portability to other platforms and can
be accomplished either during a full SQLJ translation run or on profiles previously
created.
To see summary output when translating and customizing the application MyApp:
% sqlj <...SQLJ options...> -P-Csummary MyApp.sqlj
In this example, the MyApp profiles will be created, customized, and summarized in a
single running of SQLJ.
To see summary output for MyApp profiles previously created:
% sqlj <...SQLJ options...> -P-Csummary MyApp_SJProfile*.ser
previous running of SQLJ and will be customized (if needed) and summarized in the
above running of SQLJ.
Following are two samples resulting from a -P-Csummary setting when using the
default Oracle customizer. The first example indicates no Oracle features are used:
MyApp_SJProfile0.ser: Info: Oracle features used:
MyApp_SJProfile0.ser: Info: * none
This second example indicates that Oracle features are used—several Oracle
extended data types from the oracle.sql package—and lists them:
MyApp_SJProfile0.ser: Info: Oracle features used:
MyApp_SJProfile0.ser: Info: * oracle.sql.NUMBER: 2
MyApp_SJProfile0.ser: Info: * oracle.sql.DATE: 2
MyApp_SJProfile0.ser: Info: * oracle.sql.CHAR: 2
MyApp_SJProfile0.ser: Info: * oracle.sql.RAW: 2
The following example prints out the number of usages of the Oracle setFixedCHAR()
API (enabled through the Oracle customizer fixedchar option, to account for blank
padding when binding a string into a WHERE clause for comparison against CHAR data):
% sqlj -P-Cfixedchar -P-Csummary -P-Cforce *.ser
FC_SJProfile0.ser: Info: re-installing Oracle customization
FC_SJProfile0.ser: Info: Oracle features used:
FC_SJProfile0.ser: Info: * setFixedCHAR(): 4
Note:
is detected, the summary option produces a summary regardless.

-P-Csummary<=true|false>
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Appendix A
JAR Files for Profiles

-P-Csummary

profile.Csummary<=true|false>

profile.Csummary
Default value is:

false
A.3.7 Options for Other Customizers

The Oracle SQLJ implementation provides additional, specialized customizers
described later in this chapter. These customizers also have command-line options:
• SQLCheckerCustomizer (for profile semantics-checking): See
"SQLCheckerCustomizer for Profile Semantics-Checking" for general information,
and "SQLCheckerCustomizer Options" for information about its options.
• AuditorInstaller (for debugging): See "AuditorInstaller Customizer for
Debugging" for general information, and "AuditorInstaller Options" for information
about its options.
A.3.8 SQLJ Translator Options for Profile Customization

The following SQLJ translator options relate to profile customization and are described
elsewhere in this manual:
• -default-customizer: Specify the default profile customizer to use if none is
specified in the customizer harness -customizer option.
• -profile: Specify whether to customize during this running of SQLJ.
A.4 JAR Files for Profiles

As discussed previously, you can specify a JAR file on the SQLJ command line in
order to customize any profiles that the JAR file contains.
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Appendix A
JAR Files for Profiles
Note:
• Remember that you can specify .sqlj or .java files or both on the SQLJ
command line for standard SQLJ processing, or you can specify .ser
or .jar files or both on the command line for customization only, but not
both categories.
• It is permissible for the .jar file to contain files that are not profiles. Any
file whose manifest entry indicates that the file is not a profile will be
ignored during customization.
• The .jar file is used as the class-loading context for each profile it
contains. If a profile contains a reference to a class contained within
the .jar file, then that class is loaded from the .jar file. If a profile
contains a reference to a class not in the .jar file, then the system class
loader will find and load the class according to your classpath, as usual.
A.4.1 JAR File Requirements

There are requirements for the manifest entry of each profile.
Create a plain text file with two lines for each profile that will be included in the JAR
file. One line starts with "Name:", followed by the path or package and name. The
other line is the following:
SQLJProfile: TRUE
The two lines must be consecutive (no blank line in between), and there must be a
blank line preceding line-pairs for additional profiles.
Use the JAR utility -m option to input this file.
For example, presume your MyApp application (in the directory foo/bar) has three
profiles, and you will be creating a JAR file that will include these profiles. Complete
the following steps:
1. Create a text file with the following eight lines (including the blank lines used as
separators):
Name: foo/bar/MyApp_SJProfile0.ser
SQLJProfile: TRUE
SQLJProfile: TRUE
SQLJProfile: TRUE
Presume you call this file MyAppJarEntries.txt.

2. When you run jar to create the JAR file, use the -m option to input your text file as
follows (presume you want to call the JAR file myjarfile.jar):
% jar -cvfm myjarfile.jar MyAppJarEntries.txt foo/bar/MyApp_SJProfile*.ser foo/bar/*.class
As the JAR utility constructs the manifest during creation of the JAR file, it reads
your text file and inserts the SQLJProfile: TRUE line into the manifest entry of each
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Appendix A
SQLCheckerCustomizer for Profile Semantics-Checking
profile. It accomplishes this by matching the names in the manifest with the names you
specify in your text file.
A.4.2 JAR File Logistics

When you specify a JAR file on the SQLJ command line, each profile in the JAR file is
deserialized and customized.
A JAR file is successfully customized only if all the profiles it contains are successfully
customized. After a successful customization, each profile has been reserialized into
a .ser file, the JAR file has been modified to replace the original .ser files with the
customized .ser files, and the JAR file manifest has been updated to indicate the new
entries.
If any error is encountered in the customization of any profile in a JAR file, then
the JAR file customization has failed, and the original JAR file is left completely
unchanged.
Note:
If you use signature files for authentication, the signature files that appeared
in the original JAR file will appear unchanged in the updated JAR file. You
are responsible for resigning the new JAR file if the profiles require signing.
A.5 SQLCheckerCustomizer for Profile Semantics-Checking

Oracle provides a special customizer, SQLCheckerCustomizer, that will perform
semantics-checking on a profile that was produced during previous execution of the
translator. This semantics-checking is similar to what is usually performed during
translation of the source code.
This is particularly valuable when the database to be used at run time is not
available for semantics-checking during translation. In these circumstances, you can
use SQLCheckerCustomizer after deployment, against the run-time database, typically
in a scenario where the source code is no longer available.
You can specify the checker to use. If you accept the default OracleChecker front end,
SQLCheckerCustomizer will perform online semantics-checking using an appropriate
online checker.
Note:
For online semantics-checking of the profile, you must also specify
connection parameters using the customizer harness connection options.
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Appendix A
A.5.1 Invoking SQLCheckerCustomizer with the Customizer Harness

verify Option
Following are examples of how to specify the Oracle customizer harness verify
option to run SQLCheckerCustomizer in its default mode. Because it defaults to
an online checker, you typically must provide connection parameters through the
customizer harness user, password, and url options. (The first example is a single
wraparound command line.)
% sqlj -P-verify -P-user=HR -P-url=jdbc:oracle:oci:@ Foo_SJProfile0.ser
Bar_SJProfile0.ser
Password: password
% sqlj -P-verify -P-user=HR -P-url=jdbc:oracle:oci:@ *.ser

Password: password
The verify option results in the customizer harness instantiating and invoking the
following class:
sqlj.runtime.profile.util.SQLCheckerCustomizer
This class coordinates semantics-checking of the SQL operations in the profile.

You can specify a semantics-checker or accept the default OracleChecker semantics-
checker front end.
The -P-verify option is equivalent to the following:
-P-customizer=sqlj.runtime.profile.util.SQLCheckerCustomizer
This overrides the customizer specified in the SQLJ -default-customizer option.
Note:
• As with any Oracle customizer, help output and an option list will be
provided if you specify -P-verify together with -P-help on the SQLJ
command line.
• It is important to realize that because the verify option invokes a
customizer, and only one customizer can run in any single running of
SQLJ, you cannot do any other customization when you use this option.
• You also cannot use more than one of -P-print, -P-debug, and -P-
verify simultaneously, because each of these invokes a specialized
customizer.

sqlj -P-verify <conn params> profile_list

sqlj -P-verify <conn params> Foo_SJProfile*.ser
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Appendix A
profile.verify
(You must also specify profiles, and typically customizer harness connection options,
in the SQLJ command line.)
profile.verify
Default value is:

NA
A.5.2 SQLCheckerCustomizer Options

Like any customizer, SQLCheckerCustomizer has its own options, which can be set
using the -P-C prefix on the SQLJ command line or the profile.C prefix in a SQLJ
properties file.
SQLCheckerCustomizer supports the following options:
• checker: Specify the semantics-checker to use. The default is the OracleChecker

front end, as for checking during SQLJ translation.
• warn: Specify the categories of warnings and messages to display during
semantics-checking of the profile. This is equivalent to the SQLJ -warn flag for
warning categories during translation-time semantics-checking, supports the same
settings, and uses the same defaults.
A.5.2.1 SQLCheckerCustomizer Semantics-Checker Option (checker)

The checker option enables you to specify the semantics-checker to use in checking
the SQL operations in a profile.
This defaults to the Oracle semantics-checker front end,
oracle.sqlj.checker.OracleChecker, which for SQLCheckerCustomizer chooses an
appropriate online checker for your environment.
Following is a full command-line example, showing how to use the
SQLCheckerCustomizer checker option, in conjunction with the customizer harness
verify option and connection options.
% sqlj -P-verify -P-user=HR -P-url=jdbc:oracle:oci:@ -P-
Cchecker=abc.def.MyChecker *.ser
Password: password
(This is a single wraparound command line.)

-P-Cchecker=checker_class

-P-Cchecker=a.b.c.MyChecker

profile.Cchecker=checker_class
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AuditorInstaller Customizer for Debugging

profile.Cchecker=a.b.c.MyChecker
Default value is:

A.5.2.2 SQLCheckerCustomizer Warnings Option (warn)

The warn option is equivalent to the SQLJ translator -warn option, enabling you
to choose the categories of warnings and messages to be displayed as semantics-
checking is performed on a profile.
This defaults to the all,noverbose,noportable settings, resulting in all warning
categories except verbose and portable being enabled. You will receive any warnings
regarding inheritance hierarchy requirements, data precision, conversion loss for
nullable data, and strict matching for named iterators. These are the same defaults
as for warnings during SQLJ translation.
Following is a full command-line example showing how to use the
SQLCheckerCustomizer warn option, in conjunction with the customizer harness verify
option and connection options. This would result in only portability warnings being
displayed.
% sqlj -P-verify -P-user=HR -P-url=jdbc:oracle:oci:@ -P-Cwarn=none,portable *.ser
Password: password
(This is a single wraparound command line.)

-P-Cwarn=comma-delimited_list_of_flags

-P-Cwarn=none,verbose

profile.Cwarn=comma-delimited_list_of_flags

profile.Cwarn=none,verbose
Default value is:

all,noverbose,noportable
A.6 AuditorInstaller Customizer for Debugging

For ISO code generation, SQLJ provides a special customizer, AuditorInstaller.
This customizer will insert sets of debugging statements, known as auditors, into
profiles specified on the SQLJ command line. These profiles must already exist from
previous customization.
The debugging statements will execute during SQLJ run time (when someone runs
your application), displaying a trace of method calls and values returned.
A-35
Appendix A
Use the customizer harness debug option, preceded by -P- as with any general
customization option, to insert the debugging statements. (Syntax for this option is
discussed in "Invoking AuditorInstaller with the Customizer Harness debug Option".)
A.6.1 Overview of Auditors and Code Layers

When an application is customized, Oracle customizer implements profiles in layers of
code (typically less than five) for different levels of run-time functionality. The deepest
layer uses straight Oracle JDBC calls and implements any of your SQLJ statements
that can be executed through JDBC functionality. Each higher layer is a specialized
layer for some category of SQLJ functionality that is not supported by JDBC and so
must be handled specially by the SQLJ run time. For example, a layer for iterator
conversion statements (CAST) is used to convert JDBC result sets to SQLJ iterators.
Another layer is used for assignment statements (SET).
At run time, each SQLJ executable statement is first passed to the shallowest layer
and then passed, layer-by-layer, until it reaches the layer that can process it (usually
the deepest layer, which executes all JDBC calls).
You can install debugging statements at only one layer during a single execution of
AuditorInstaller. Each set of debugging statements installed at a particular layer of
code is referred to as an individual auditor. During run time, an auditor is activated
whenever a call is passed to the layer at which the auditor is installed.
Any one of the specialized code layers above the JDBC layer is usually of no particular
interest during debugging, so it is typical to install an auditor at either the deepest
layer or the shallowest layer. If you install an auditor at the shallowest layer, its run-
time debugging output will be a trace of method calls resulting from all your SQLJ
executable statements. If you install an auditor at the deepest layer, its run-time output
will be a trace of method calls from all your SQLJ executable statements that result in
JDBC calls.
Use multiple executions of AuditorInstaller to install auditors at different levels. You
might want to do that to install auditors at both the deepest layer and the shallowest
layer, for example.
See "AuditorInstaller Depth Option (depth)" for information about how to specify the
layer at which to install an auditor.
A.6.2 Invoking AuditorInstaller with the Customizer Harness debug

Option
Following are examples of how to specify the Oracle customizer harness debug option
to run AuditorInstaller in its default mode:
% sqlj -P-debug Foo_SJProfile0.ser Bar_SJProfile0.ser
% sqlj -P-debug *.ser
% sqlj -P-debug myappjar.jar
The debug option results in the customizer harness instantiating and invoking the
following class:
% sqlj.runtime.profile.util.AuditorInstaller
A-36
Appendix A
This class performs the work of inserting the debugging statements.

The -P-debug option is equivalent to the following:
-P-customizer=sqlj.runtime.profile.util.AuditorInstaller
This overrides the customizer specified in the SQLJ -default-customizer option.

• To run an application with auditors installed, the SQLJ file translator.jar must
be in your classpath. (Usually, running a already translated SQLJ application
requires only a runtime library.)
• As with any Oracle customizer, help output and an option list will be provided if you
specify -P-debug together with -P-help on the SQLJ command line.
• It is important to realize that because the debug option invokes a customizer, and
only one customizer can run in any single running of SQLJ, you cannot perform
any other customization when you use this option.
• You also cannot use more than one of -P-print, -P-debug, and -P-verify
simultaneously, because each of these invokes a specialized customizer.
sqlj -P-debug profile_list

sqlj -P-debug Foo_SJProfile*.ser

profile.debug
(You must also specify profiles in the file list.)

profile.debug
Default value is:

NA
A.6.3 AuditorInstaller Run-Time Output

During run time, debugging statements placed by AuditorInstaller result in a trace
of methods called and values returned. This happens for all profile layers that had
debugging statements installed. There is no means of selective debug output at run
time.
AuditorInstaller output relates to profiles only; there is currently no mapping to lines
in your original .sqlj source file.
Following is a sample portion of AuditorInstaller run-time output. This is what the

output might look like for a SQLJ SELECT INTO statement:
oracle.sqlj.runtime.OraProfile@1 . getProfileData ( )
oracle.sqlj.runtime.OraProfile@1 . getProfileData returned
sqlj.runtime.profile.ref.ProfileDataImpl@2
A-37
Appendix A
oracle.sqlj.runtime.OraProfile@1 . getStatement ( 0 )
oracle.sqlj.runtime.OraProfile@1 . getStatement returned
oracle.sqlj.runtime.OraRTStatement@3
oracle.sqlj.runtime.OraRTStatement@3 . setMaxRows ( 1000 )
oracle.sqlj.runtime.OraRTStatement@3 . setMaxRows returned
oracle.sqlj.runtime.OraRTStatement@3 . setMaxFieldSize ( 3000 )
oracle.sqlj.runtime.OraRTStatement@3 . setMaxFieldSize returned
oracle.sqlj.runtime.OraRTStatement@3 . setQueryTimeout ( 1000 )
oracle.sqlj.runtime.OraRTStatement@3 . setQueryTimeout returned
oracle.sqlj.runtime.OraRTStatement@3 . setBigDecimal ( 1 , 5 )
oracle.sqlj.runtime.OraRTStatement@3 . setBigDecimal returned
oracle.sqlj.runtime.OraRTStatement@3 . setBoolean ( 2 , false )
oracle.sqlj.runtime.OraRTStatement@3 . setBoolean returned
oracle.sqlj.runtime.OraRTStatement@3 . executeRTQuery ( )
oracle.sqlj.runtime.OraRTStatement@3 . executeRTQuery returned
oracle.sqlj.runtime.OraRTResultSet@6
oracle.sqlj.runtime.OraRTStatement@3 . getWarnings ( )
oracle.sqlj.runtime.OraRTStatement@3 . getWarnings returned null
oracle.sqlj.runtime.OraRTStatement@3 . executeComplete ( )
oracle.sqlj.runtime.OraRTStatement@3 . executeComplete returned
oracle.sqlj.runtime.OraRTResultSet@6 . next ( )
oracle.sqlj.runtime.OraRTResultSet@6 . next returned true
oracle.sqlj.runtime.OraRTResultSet@6 . getBigDecimal ( 1 )
oracle.sqlj.runtime.OraRTResultSet@6 . getBigDecimal returned 5
oracle.sqlj.runtime.OraRTResultSet@6 . getDate ( 7 )
oracle.sqlj.runtime.OraRTResultSet@6 . getDate returned 1998-03-28
There are two lines for each method call. The first shows the call and input
parameters; the second shows the return value.
Note:
The classes you see in the oracle.sqlj.runtime package are SQLJ run-
time classes with equivalent functionality to similarly named JDBC classes.
For example, OraRTResultSet is the SQLJ run-time implementation of the
JDBC ResultSet interface, containing equivalent attributes and methods.
A.6.4 AuditorInstaller Options

As with any customizer, AuditorInstaller has its own options that can be set using
the -P-C prefix on the SQLJ command line (or profile.C in a SQLJ properties file).
AuditorInstaller supports the following options:
• depth: Specify how deeply you want to go into the layers of run-time functionality
in your profiles.
• log: Specify the target file for run-time output of the debugging statements of the
installed auditor.
• prefix: Specify a prefix for each line of run-time output that will result from this
installation of debugging statements.
• showReturns: Enable the installed auditor to include return arguments in its run-
time call tracing.
A-38
Appendix A
• showThreads: Enable the installed auditor to include thread names in its run-time
call tracing (relevant only for multithreaded applications).
• uninstall: Remove the debugging statements placed into the profiles during the
most recent previous invocation of AuditorInstaller on those profiles.
A.6.4.1 AuditorInstaller Depth Option (depth)

As discussed in "Overview of Auditors and Code Layers", AuditorInstaller can
install a set of debugging statements, known as an auditor, at only a single layer of
code during any one execution. The AuditorInstaller depth option enables you to
specify which layer. Use multiple executions of AuditorInstaller to install auditors at
different levels.
Layers are numbered in integers. The shallowest depth is layer 0; a maximum depth of
2 or 3 is typical. The only depth settings typically used are 0 for the shallowest layer or
-1 for the deepest layer. In fact, it is difficult to install an auditor at any other particular
layer, because the layer numbers used for the various kinds of SQLJ executable
statements are not publicized.
The depth option is sometimes used in conjunction with the prefix option. By running
AuditorInstaller more than once, with different prefixes for different layers, you can
see at runtime what information is coming from which layers.
If you do not set the depth option, or the specification exceeds the number of layers in
a given profile, then an auditor will be installed at the deepest layer.
-P-Cdepth=n

-P-Cdepth=0

profile.Cdepth=n

profile.Cdepth=0
Default value is:

-1 (deepest layer)
A.6.4.2 AuditorInstaller Log File Option (log)

Use the log option to specify an output file for runtime output that will result from the
auditor that you are currently installing. Otherwise, standard output will be used, so
that debug output will go to wherever SQLJ messages go.
When auditors write messages to an output file, they append; they do not overwrite.
Therefore, you can specify the same log file for multiple auditors without conflict.
In fact, it is typical in this way to have debug information from all layers of your
application go to the same log file.
A-39
Appendix A
-P-Clog=log_file

-P-Clog=foo/bar/mylog.txt

profile.Clog=log_file

profile.Clog=foo/bar/mylog.txt
Default value is:

Empty (for standard output)
A.6.4.3 AuditorInstaller Prefix Option (prefix)

Use the prefix option to specify a prefix for each line of runtime output resulting from
the debugging statements installed during this invocation of AuditorInstaller.
This option is often used in conjunction with the depth option. By running
AuditorInstaller multiple times with different prefixes for different layers, you can
easily see at runtime what information is coming from which layers.
-P-Cprefix="string"

-P-Cprefix="layer 2: "

profile.Cprefix="string"

profile.Cprefix="layer 2: "
Default value is:

Empty
A.6.4.4 AuditorInstaller Return Arguments Option (showReturns)

Use the showReturns option to enable or disable the display of return arguments as
part of the runtime call tracing. This is enabled by default.
The following few lines show sample output with showReturns enabled (default):
oracle.sqlj.runtime.OraRTStatement@3 . executeComplete returned
oracle.sqlj.runtime.OraRTResultSet@6 . next returned true
oracle.sqlj.runtime.OraRTResultSet@6 . getBigDecimal returned 5
A-40
Appendix A
oracle.sqlj.runtime.OraRTResultSet@6 . getDate returned 1998-03-28
With showReturns disabled, the output would appear as follows:

Instead of both a call line and a return line for each method call, there is only a call
line.
-P-CshowReturns<=true|false>

-P-CshowReturns=false

profile.CshowReturns<=true|false>

profile.CshowReturns=false
Default value is:

true
A.6.4.5 AuditorInstaller Thread Names Option (showThreads)

Use the showThreads option to enable or disable the display of thread names as
part of the runtime call tracing (relevant only for multithreaded applications). This is
disabled by default.
When this option is enabled, thread names prefix the method names in the trace
output.
-P-CshowThreads<=true|false>

-P-CshowThreads

profile.CshowThreads<=true|false>

profile.CshowThreads
Default value is:

false
A-41
Appendix A
A.6.4.6 AuditorInstaller Uninstall Option (uninstall)

Use the uninstall option to remove debugging statements placed during previous
invocations of AuditorInstaller. Each time you use the uninstall option, it will
remove the auditor most recently installed.
To remove all auditors from a profile, run AuditorInstaller repeatedly until you get a
message indicating that the profile was unchanged.
-P-Cuninstall

-P-Cuninstall

profile.Cuninstall

profile.Cuninstall
Default value is:

Disabled
A.6.5 Full Command-Line Examples

Following are some full SQLJ command-line examples showing the specification of
AuditorInstaller options.
Insert a set of debugging statements, or auditor, into the deepest layer (which is the
default layer), with runtime output to standard output:
% sqlj -P-debug MyApp_SJProfile*.ser
Insert an auditor into the deepest layer, with runtime output to log.txt:
% sqlj -P-debug -P-Clog=foo/bar/log.txt MyApp_SJProfile*.ser
Insert an auditor into the deepest layer, with runtime output to standard output,
showing thread names but not return arguments:
% sqlj -P-debug -P-CshowThreads=true -P-CshowReturns=false MyApp_SJProfile*.ser
Insert an auditor into layer 0 (the shallowest layer). Send runtime output to log.txt;
prefix each line of runtime output with "Layer 0: " (the following command is a single
wraparound line):
% sqlj -P-debug -P-Clog=foo/bar/log.txt -P-Cdepth=0 -P-Cprefix="Layer 0: "
MyApp_SJProfile*.ser
Uninstall an auditor (this uninstalls the auditor most recently installed; do it repeatedly
to uninstall all auditors):
% sqlj -P-debug -P-Cuninstall MyApp_SJProfile*.ser
A-42
Index
A BigDecimal
support, 6-35
access mode settings (transactions), 8-46 binary portability of profiles, 4-37
alternative environments, support, 9-66 bind-by-identifier option (sqlj -bind-by-identifier),
applets, using SQLJ, 3-14 9-54
arrays BLOB support, 6-24
as iterator columns, 6-7 BOOLEAN type (PL/SQL), 6-8
VARRAYs, 7-4
assignment statements (SET), 5-44
assumptions, environment, 2-1
C
AuditorInstaller C prefix (sqlj -C-x), 9-51
command-line examples, A-42 cache option (sqlj -cache), 9-59
customizer for debugging, A-35 caching online checker results, 9-59
invoking, A-36 caching statements, 11-3
options, A-38 CALL syntax for stored procedures, 5-45
runtime output, A-37 calling stored functions, 5-46
auditors in profiles for debugging, A-36 calling stored procedures, 5-45
auto-commit calls to runtime, generated, 10-3
modifying in existing connection, 4-23 case-sensitive SQL UDT names, 7-9
specifying in new connection, 4-22 cause/action output for errors, 9-35
CHAR comparisons, blank padding, 9-43, A-26
B character encoding
command line example, 10-18
backup option (customizer harness), A-9 for messages, 10-18
backward compatibility for source, 10-18
Oracle SQLJ, general, 2-3 overview, 10-15
to Oracle8i, 6-9 setting at runtime, 10-24
batch updates using native2ascii, 10-24
batch limit, 11-10 check source name against. public class, 9-66
batchable and compatible statements, 11-10 check sources, expand resolution search, 9-54
batching incompatible statements, 11-10 checker option (SQLCheckerCustomizer), A-34
canceling a batch, 11-10 checkfilename option (sqlj -checkfilename), 9-66
cautions, 11-10 checksource option (sqlj -checksource), 9-54
enabling and disabling, 11-10 classpath and path, 2-4
error conditions during execution, 11-10 classpath option (sqlj -classpath), 9-18
explicit and implicit batch execution, 11-10 clauses, SQLJ executable statements, 5-9
overview, 11-10 CLOB support, 6-24
update counts, 11-10 CLOSE_CONNECTION, 8-51
using implicit execution contexts, 11-10 close() method (DefaultContext), 4-12
with respect to recursive call-ins, 11-10 close() method (ExecutionContext), 8-32
BetterDate (custom Java class), 7-12 close() method (Oracle class), 4-11, 4-12
BFILEs code generation
as stored function results, 6-24 general information, 10-3
BFILE support, 6-24 Oracle-specific vs. ISO standard, 4-34
translator -codegen option, 9-43
Index-1
Index
code layers in profiles, A-36 connect() method (Oracle class), 4-11

codegen option (SQLJ -codegen), 9-43 connection context
collections concepts, 8-1
about custom Java classes, 7-5 declaring and using, 8-4
creating collection types, 7-16 example, 8-6
data types, 7-4 implementation and functionality, 8-7
fundamentals, 7-4 logistics, 8-3
ORAData specifications, 7-5 semantics-checking, 8-9
overview of collection support, 7-1 connection contexts, 8-1
strongly typed, 7-24 close connection, 8-7
weak types, restrictions, 7-38 concepts, 8-2
weak types, support, 7-37 converting from JDBC connection, 8-48
column definitions (types/sizes) converting to JDBC connection, 8-48
general information, 11-18 declaration with IMPLEMENTS clause, 8-8
Oracle customizer optcols option, A-21 declarations, 5-3
SQLJ -optcols option, 9-43 declaring connection context class, 8-4
command line (translator) from SQLJ data sources, 8-12, 8-15
echoing without executing, 9-10 get default connection, 8-7
example, 9-10 get execution context, 8-7
overview, 9-1 get JDBC connection, 8-7
syntax and arguments, 9-10 implementation and functionality, 8-7
commit instantiating connection object, 8-4
automatic vs. manual, 4-22 methods, 8-7
effect on iterators and result sets, 4-24 multiple connections, example, 8-6
manual, 4-23 relation to execution contexts, 8-26
modifying auto-commit in existing semantics-checking, 8-9
connection, 4-23 set default connection, 8-7
specifying auto-commit in new connection, specifying connection for statement, 8-4
4-22 specifying for executable statement, 5-11
compat(ibility) option (Oracle customizer), A-20 connections
compilation closing, 4-9
compiling in two passes, 9-66 closing shared connections with JDBC, 8-48
during translation, 10-7 from SQLJ data sources, 8-12, 8-15
enabling/disabling, 9-54 JDBC transaction methods, 8-47
compile option (sqlj -compile), 9-54 modifying auto-commit, 4-23
compiler multiple, using declared connect contexts,
classpath option, 9-18 4-10
option support for javac, 9-2 Oracle class to connect, 4-11
options through SQLJ, 9-51 set up, 2-7
related options, 9-66 shared connections with JDBC, 8-48
required behavior, 9-67 single or multiple using default context, 4-6
specifying name, 9-66 specifying auto-commit, 4-22
compiler encoding support option (sqlj), 9-66 translator options, 9-26
compiler executable option (sqlj), 9-66 verify, 2-7
compiler message output pipe option (sqlj), 9-66 context expressions
compiler output file option (sqlj -compiler...), 9-66 evaluation at runtime, 5-18
components option (sqlj -components), 9-40 overview, 5-18
configuration and installation verification, 2-4 context option (customizer harness), A-9
connect string converting .ser profiles to .class, 9-54
for OCI driver, 4-2 CURSOR syntax (nested tables), 7-25
for Thin driver, 4-3 custom Java classes
server-side internal driver, 4-4 about custom Java classes, 7-5
server-side Thin driver, 4-3 compiling, 7-11
SIDs deprecated, 2-7 reading and writing data, 7-12
use of database service names, 2-7 requirements, 7-7
Index-2
Index
custom Java classes (continued) data source support (continued)

sample class, 7-12 requirements, 8-10
strongly typed, definition, 7-2 SQLJ data source classes, 8-12
support for object methods, 7-7 SQLJ data source interfaces, 8-12
using to serialize object, 7-33 SQLJ-specific data sources, 8-12
weakly typed, definition, 7-2 database connection, verify, 2-7
customization database URL
converting .ser profiles to .class, 9-54 default prefix for online checking, 9-26
creation and registration, A-5 SIDs deprecated, 2-7
customizer harness connection options, A-12 use of database service names, 2-7
customizer harness general options, A-8 DBMS_LOB package, 6-24
customizer harness options overview, A-7 debug option (customizer harness), A-16
defining column types/sizes, A-21 debugging
defining parameter sizes, A-23 AuditorInstaller command-line examples,
during translation, 10-8 A-42
enabling/disabling, 9-54 AuditorInstaller customizer, A-35
error and status messages, A-6 AuditorInstaller options, A-38
force customization, A-21 AuditorInstaller runtime output, A-37
jar file usage, A-30 debug option, customizer harness, A-16
more about customization, A-3 in JDeveloper, 11-22
options, A-7 invoking AuditorInstaller, A-36
options to invoke special customizers, A-15 line-mapping, SQLJ source to class, 9-35
Oracle customizer options, A-19 line-mapping, SQLJ source to class for jdb,
overview/syntax of customizer-specific 9-35
options, A-18 declarations
parameter default sizes, A-24 connection context declarations, 5-3
related SQLJ options, A-30 IMPLEMENTS clause, 5-4
show SQL transformations, A-26 iterator declarations, 5-3
statement cache size, A-27 overview, 5-1
steps in process, A-4 WITH clause, 5-5
summary of Oracle features used, A-29 default connection
version compatibility, A-20 setting with Oracle.connect(), 4-6
customizer, 4-36 setting with setDefaultContext(), 4-9
customizer harness default customizer option (sqlj), 9-72
connection options, A-12 default properties files (translator), 9-13
general options, A-8 default semantics-checker, 9-59
invoke special customizers, A-15 default URL prefix option (sqlj), 9-26
options overview, A-7 DefaultContext class
overview, A-4 close() method parameters, 4-12
customizer option (customizer harness), A-10 constructors, 4-12
customizers key methods, 4-12
choosing, A-7 use for single or multiple connections, 4-6
option to choose customizer, A-10 defining column types/sizes, 11-18
overview, A-4 defining parameter sizes, 11-19
passing options through SQLJ, 9-51 demo applications (SQLJ), availability, 2-4
specifying default, 9-72 depth option (AuditorInstaller), A-39
digests option, jar (customizer harness), A-10
dir option (sqlj -dir), 9-23
D directory
d option (sqlj -d), 9-23 for generated .class and .ser, 9-23
data source support for generated .java, 9-23
associating a connection, 8-10 dirty reads, 8-46
associating a default context, 8-10 DMS support
auto-commit mode, 8-10 command-line options for DMS, 9-40, 11-24
general overview, 8-10 examples, 11-29
Index-3
Index
DMS support (continued) executable statements (continued)

overview of DMS support, 11-23 SQLJ clauses, 5-9
runtime commands for DMS, 11-25 using PL/SQL blocks, 5-12
sensors and metrics, 11-26 execution contexts
SQLJ DMS properties files, 11-25 cancellation method, 8-30
driver option (customizer harness), A-15 close() method, 8-32
driver registration option (sqlj -driver), 9-26 control methods, 8-29
Dynamic Monitoring Service, SQLJ support, creating and specifying, 8-27
11-22 method usage, example, 8-32
dynamic SQL overview, 8-25
defined, 3-1 relation to connection contexts, 8-26
in JDBC code, 8-47 relation to multithreading, 8-33
in PL/SQL code, 5-12 savepoint methods, 8-31
dynamic SQL support in SQLJ specifying for executable statement, 5-11
examples, 8-56 status methods, 8-29
introduction, 8-54 synchronization, 8-28
meta bind expressions, 8-55 update-batching methods, 8-31
runtime behavior, 8-55 exemplar schema, 4-15
translation-time behavior, 8-55 exit codes, translator, 10-12
explain option (sqlj -explain), 9-35
extending iterator classes, 8-38
E extensions
echo option, without execution, 9-18 overview, 3-3
echoing command line without executing, 9-10 performance extensions, 11-1
encoding summary of features used, A-29
character encoding for messages, 10-18 type extensions, 6-22
character encoding for source, 10-18
command line example, 10-18 F
do not pass option to compiler, 9-66
overview of character encoding, 10-15 FETCH CURRENT syntax (iterators), 8-39
setting at runtime, 10-24 file name requirements and restrictions, 4-46
using native2ascii, 10-24 fixedchar option (Oracle customizer), A-26
encoding option, source files (sqlj -encoding), fixedchar option (SQLJ -fixedchar), 9-43
9-23 flags for special processing, 9-54
environment assumptions and requirements, 2-1 force option (Oracle customizer), A-21
environment variable, translator options, 9-16 function calls, stored, 5-46
environments--scenarios and limitations, 2-2
errors
character encoding for messages, 10-18
G
customization messages, A-6 getConnection() method (Oracle class), 4-11
messages, codes, and SQL states, 4-19 globalization support
outputting cause and action, 9-35 character encoding, language support, 10-15
runtime categories, 10-14 outside of SQLJ, 10-24
translator error, warning, info messages, 10-9 overview, 3-17
exceptions related data types, 6-2
exception-handling requirements, 4-18 related Java types, 10-21
processing, 4-19 related SQLJ and Java settings, 10-18
set up exception-handling, 4-26 support for Unicode characters, 10-20
using SQLException subclasses, 4-20
executable statements
examples, 5-11 H
overview, 5-8 help option (customizer harness), A-11
rules, 5-9 help options (sqlj -help-xxxx), 9-18
specifying connection/execution contexts, hints in code, parameter sizes, 11-19
5-11
Index-4
Index
host expressions iterators (continued)

basic syntax, 5-15 nested iterators for nested tables, 7-28
bind by identifier, 9-54 overview, 5-28
evaluation at runtime, 5-18 positional iterators, using next(), 5-36
examples, 5-17 result set iterators (strongly typed), 5-29
examples of evaluation at runtime, 5-20 result set iterators (weakly typed), 5-31, 8-38
iterators and result sets as host variables, scrollable, 8-39
5-39 scrollable result set iterators, 8-39
overview, 5-14 selecting objects and references, 7-20
restrictions, 5-25 set up named iterator (example), 4-26
selecting a nested table, 7-26 subclassing, 8-38
supported types for JDBC 2.0, 6-6 using named iterators, 5-33
type support for Oracle8i, 6-9 using positional iterators, 5-36
type support summary, 6-2 using weakly typed iterators, 8-52
host variables, 3-7 with serialized objects, 7-35
I J
IDE SQLJ integration, 3-17 J prefix (sqlj -J-x), 9-51
IMPLEMENTS clause jar file digests option, customization, A-10
in connection context declarations, 8-8 jar files for profiles, A-30
in iterator declarations, 8-37 Java bind expressions (dynamic SQL), 8-55
syntax, 5-4 Java properties, getProperty(), 10-24
importing required classes, 4-26 Java VM
informational messages, translator, 10-9 classpath option, 9-18
input to translator, 3-8 options through SQLJ, 9-51
installation and configuration verification, 2-4 specifying name, 9-66
instrument option (sqlj -instrument), 9-40 JavaBeans for SQLJ connections, 8-15
instrumenting class file (linemap), 9-39 javac compatibility, 9-2
interoperability with JDBC JDBC 2.0
connection contexts and connections, 8-48 support for LOB types, 6-22
iterators and result sets, 8-52 support for weakly typed Struct, Ref, Array,
isolation level settings (transactions), 8-46 7-37
iterators types supported, 6-6
accessing named iterators, 5-33 JDBC connection methods (transactions), 8-47
accessing positional iterators, 5-36 JDBC driver registration option (sqlj -driver), 9-26
array columns, 6-7 JDBC drivers
as host variables, 5-39 Oracle drivers, 4-1
as iterator columns (nested), 5-42 select for translation, 4-4
as stored function returns, 5-47 select/register for customization, A-15
commit/rollback effect, 4-24 select/register for runtime, 4-4
concepts, 5-29 verify, 2-8
converting from result sets, 8-52 JDBC interoperability
converting to result sets, 8-52 connection contexts and connections, 8-48
declarations, 5-3 iterators and result sets, 8-52
declaring named iterators, 5-33 JDBC vs. SQLJ, sample application, 3-11
declaring positional iterators, 5-36 jdblinemap option (sqlj -jdblinemap), 9-35
declaring with IMPLEMENTS clause, 8-37 JDeveloper
extending, 8-38 debugging with, 11-22
general steps in using, 5-31 SQLJ integration, 3-17
instantiating/populating named iterators, 5-33 JDK
instantiating/populating positional iterators, supported versions, 2-2
5-36 JNDI
iterator class functionality, 8-36 name of default data source, 8-10
named vs. positional, 5-32 use for data sources, connections, 8-10
Index-5
Index
K NcharAsciiStream class (globalization support),

10-20
KEEP_CONNECTION, 8-51 NcharUnicodeStream class (globalization
support), 10-20
NCLOB class (globalization support), 10-20
L nested iterators, 7-28
language support (globalization support), 10-15 nested tables
line-mapping accessing, 7-25
SQLJ source to class file, 9-35 inserting in SQLJ, 7-25
SQLJ source to class for jdb, 9-35 manipulating, 7-27
linemap option (sqlj -linemap), 9-35 selecting into host expression, 7-26
loadjava types, 7-4
compatibility options, SQLJ, 9-2 using nested iterator, 7-28
LOBs non-repeatable reads, 8-46
as iterator columns, 6-24 NString class, 10-20
as stored function results, 6-24 NString class (globalization support), 10-20
FETCH INTO LOB host variables, 6-24 null-handling
SELECT INTO LOB host variables, 6-24 examples, 4-17
support (oracle.sql and DBMS_LOB), 6-24 wrapper classes for null-handling, 4-16
locale
command line example, 10-18 O
for messages, 10-18
setting at runtime, 10-24 object references
log option (AuditorInstaller), A-39 selecting into iterators, 7-20
strongly typed in SQLJ, 7-20
updating in SQLJ, 7-23
M weak types, restrictions, 7-38
message pipe, compiler, 9-66 weak types, support, 7-37
meta bind expressions (dynamic SQL), 8-55 objects
method support for objects, 7-7 about custom Java classes, 7-5
middle-tier considerations, 4-47 creating object types, 7-16
multithreading data types, 7-4
in SQLJ, overview, 8-33 fundamentals, 7-3
relation to execution contexts, 8-33 inserting in SQLJ, 7-22
sample application, 8-33 method support, 7-7
ORAData specifications, 7-5
overview of object support, 7-1
N selecting into iterators, 7-20
n option (sqlj -n) (echo without execution), 9-18 serializing (overview), 7-30
name of compiler, 9-66 serializing RAW and BLOB columns, 7-31
name of Java VM, 9-66 serializing with custom Java class, 7-33
named iterators SQLData specifications, 7-5
accessing, 5-33 strongly typed in SQLJ, 7-20
declaring, 5-33 updating a reference in SQLJ, 7-23
instantiating and populating, 5-33 updating in SQLJ, 7-21
scrollable, 8-39 weak types, restrictions, 7-38
using, 5-33 weak types, support, 7-37
naming requirements and restrictions OCI driver (JDBC), 4-1
file names, 4-46 offline checking
local variables, classes (Java namespace), default checker, Oracle checkers, 9-59
4-44 specifying checker, 9-59
SQL namespace, 4-46 offline option (sqlj -offline), 9-59
SQLJ namespace, 4-46 offline parsing
native2ascii for encoding, 10-24 sqlj -parse option, 9-59
NCHAR class (globalization support), 10-20 steps involved, 10-2
Index-6
Index
offline parsing (continued) Oracle customizer (continued)

vs. online checking, 9-59 force customization, A-21
online checking options, A-19
caching results, 9-59 set default parameter sizes, A-24
default checker, Oracle checkers, 9-59 show SQL transformation, A-26
enabling, setting user schema, 9-26 statement cache size, A-27
registering drivers, 9-26 summary of Oracle features used, A-29
setting default URL prefix, 9-26 version compatibility, A-20
setting password, 9-26 Oracle extensions
setting URL, 9-26 overview, 3-3
specifying checker, 9-59 performance extensions, 11-1
vs. offline parsing, 9-59 summary of features used, A-29
online option (sqlj -online), 9-59 type extensions, 6-22
opaque types, 7-38 Oracle optimizer, 11-2
optcols option (Oracle customizer), A-21 Oracle system identifiers (SIDs) in connect
optcols option (SQLJ -optcols), 9-43 strings, deprecated, 2-7
optimizer, SQL, 11-2 Oracle-specific code generation
options (translator) advantages and disadvantages, 4-34
command line only, 9-18 coding considerations, limitations, 4-32
flags for special processing, 9-54 environment requirements, 4-31
for connections, 9-26 introduction, 4-31, 4-44
for customization, 9-72 translator/customizer usage changes, 4-33
for javac compatibility, 9-2 oracle.sql package, 6-23
for loadjava compatibility, 9-2 OracleChecker default checker, 9-59
for output files and directories, 9-23 ORAData
for reporting and line-mapping, 9-35 additional uses, 7-12
for semantics-checking, offline parsing, 9-59 specifications, 7-5
for VM and compiler, 9-66 output directory
help, 9-18 for generated .class and .ser, 9-23
order of precedence, 9-16 for generated .java, 9-23
overview, 9-2 output file and directory options (translator), 9-23
prefixes for passing options, 9-51 output file for compiler, 9-66
summary list, 9-2 output from translator, 3-8
support for alternative environments, 9-66 output pipe, compiler messages, 9-66
options for customizer harness Overview of SQLJ, 3-1
connection options, A-12
general options, A-8
invoke special customizers, A-15
P
overview, A-7 P prefix (sqlj -P-x), 9-51
options for Oracle customizer, A-19 parameter definitions (sizes)
optparamdefaults option (Oracle customizer), general information, 11-19
A-24 Oracle customizer optparamdefaults option,
optparamdefaults option (SQLJ - A-24
optparamdefaults), 9-43 Oracle customizer optparams option, A-23
optparams option (Oracle customizer), A-23 SQLJ -optparamdefaults option, 9-43
optparams option (SQLJ -optparams), 9-43 SQLJ -optparams option, 9-43
Oracle class parse option (sqlj -parse), 9-59
close() method parameters, 4-11 passes option (sqlj -passes), 9-66
connect() method, 4-11 passes, two-pass compiling, 9-66
for DefaultContext instances, 4-11 passing options to other executables, 9-51
getConnection() method, 4-11 password option (customizer harness), A-14
Oracle customizer password option for checking (sqlj), 9-26
blank padding for CHAR comparisons, A-26 path and classpath, 2-4
define column types/sizes, A-21 performance enhancements, 11-1
define parameter sizes, A-23 performance monitoring, DMS support, 11-22
Index-7
Index
phantom reads, 8-46 props option (sqlj -props), 9-18

pipe, compiler output messages, 9-66 public class name / source name check, 9-66
PL/SQL
blocks in executable statements, 5-12
BOOLEAN type, 6-8
R
RECORD type, 6-8 READ COMMITTED transactions, 8-46
TABLE type, 6-8 READ ONLY transactions, 8-46
plan baselines, 8-65 READ UNCOMMITTED transactions, 8-46
command-line options, 8-66 READ WRITE transactions, 8-46
generated Java file, 8-73 RECORD type (PL/SQL), 6-8
generated log file, 8-72 REF CURSOR
generated SQL file, 8-71 about REF CURSOR types, 6-33
property file options, 8-66 example, 6-33
positional iterators SQLJ support, 6-33
accessing, 5-36 register JDBC drivers
declaring, 5-36 for runtime, 4-4
instantiating and populating, 5-36 for translation, 9-26
navigation with next(), 5-36 registering column types/sizes, 11-18
scrollable, 8-39 registering parameter sizes, 11-19
using, 5-36 REPEATABLE READ transactions, 8-46
positioned delete, 6-29 reporting options (translator), 9-35
positioned update, 6-29 requirements, environment, 2-2
prefetching rows, 11-2 result expressions
prefix option (AuditorInstaller), A-40 evaluation at runtime, 5-18
prefixes overview, 5-18
to pass options to customizer, 9-51 result set iterators (strongly typed)
to pass options to Java compiler, 9-51 Overview, 5-29
to pass options to Java VM, 9-51 result set iterators (weakly typed)
print option (customizer harness), A-16 general information, 8-38
procedure calls, stored, 5-45 Overview, 5-31
profile customization (see customization), 10-8 scrollable, 8-39
profile option (sqlj -profile), 9-54 result sets
profile-keys, 4-40 as host variables, 5-39
profile-keys class, 4-38, 10-3 as iterator columns, 5-42
profiles as stored function returns, 5-47
auditors for debugging, A-36 commit/rollback effect, 4-24
binary portability, 4-37 converting from iterators, 8-52
code layers, A-36 converting to iterators, 8-52
creation during code generation, A-2 ResultSetIterator type, 8-38
debug option, A-16 returnability (cursor states, WITH clause), 5-7
functionality at runtime, A-6 rollback
generated profiles, 10-3 effect on iterators and result sets, 4-24
more about profiles, A-1 manual, 4-23
overview, 4-36 with savepoint, 4-25
print option, A-16 row prefetching, 11-2
sample profile entry, A-2 ROWID
use of jar files, A-30 as stored function results, 6-29
verify option, A-17 FETCH INTO ROWID host variable, 6-29
properties files (translator) SELECT INTO ROWID host variable, 6-29
default properties files, 9-13 support, 6-29
overview, 9-13 runtime
setting input file, 9-18 categories of errors, 10-14
syntax, 9-13 debugging output (AuditorInstaller), A-37
properties files, SQLJ DMS, 11-25 functionality, 10-12
properties, Java, getProperty(), 10-24 functionality of profiles, A-6
Index-8
Index
runtime (continued) ser2class option (sqlj -ser2class), 9-54

generated calls to runtime, 10-3 SERIALIZABLE transactions, 8-46
globalization support, 10-15 serialized objects
JDBC driver selection and registration, 4-4 as host variables, 7-35
overview, 3-3, 4-36 in iterator columns, 7-35
packages, 10-13 overview, 7-30
set up connection, 2-7 SerializableDatum class (sample), 7-36
steps in runtime processing, 3-10 through custom Java class, 7-33
test, 2-8 to RAW and BLOB columns, 7-31
server-side internal driver (JDBC), 4-1
server-side Thin driver (JDBC), 4-1
S SET (assignment) statements, 5-44
sample applications SET TRANSACTION syntax, 8-45
JDBC vs. SQLJ, 3-11 setFormOfUse method, 10-22
multiple connection contexts, 8-6 setup of SQLJ, testing, 2-6
multiple-row query (named iterator), 4-26 showReturns option (AuditorInstaller), A-40
multithreading, 8-33 showSQL option (Oracle customizer), A-26
single-row query (SELECT INTO), 4-26 showThreads option (AuditorInstaller), A-41
sample classes SIDs in connect strings, deprecated, 2-7
custom Java class (BetterDate), 7-12 source check for type resolution, 9-54
SerializableDatum class, 7-36 source file line-mapping
savepoints for jdb, 9-35
ExecutionContext savepoint methods, 8-31 general, 9-35
ISO syntax, 4-25 source files encoding option, 9-23
Oracle syntax, 4-25 source name / public class name check, 9-66
savepoint statements, 4-25 SQL optimizer, 11-2
scrollable iterators SQL replacement code (dynamic SQL), 8-55
declaring, 8-39 SQL states (for errors), 4-19
scrollable named iterators, 8-39 SQLCheckerCustomizer
scrollable positional iterators, 8-39 for semantics-checking of profiles, A-32
sensitivity, 8-39 invoking, A-33
the scrollable interface, 8-39 options, A-34
ScrollableResultSetIterator type, 8-39 SQLData
SELECT INTO statements specifications, 7-5
error conditions, 5-28 SQLException subclasses, using, 4-20
examples, 5-27 SQLJ vs. JDBC, sample application, 3-11
syntax, 5-26 SQLJ_OPTIONS environment variable, 9-16
semantics-checking SqljConnBean for simple connection, 8-15
caching online results, 9-59 SqljConnCacheBean for connection caching,
default checker, Oracle checkers, 9-59 8-15
enabling online, setting user schema, 9-26 sqljutl package, 2-5
invoking SQLCheckerCustomizer, A-33 statement caching, 11-3
of profiles, via customizer harness, A-17 static SQL, defined, 3-1
options, 9-59 status messages
registering drivers, 9-26 for customization, A-6
setting default URL prefix, 9-26 for translation, 10-11
setting password, 9-26 translator, enabling/disabling, 9-35
setting URL, 9-26 status option (sqlj -status), 9-35
specifying offline checker, 9-59 stmtcache option (Oracle customizer), A-27
specifying online checker, 9-59 stored function calls, 5-46
SQLCheckerCustomizer options, A-34 stored outlines, 8-59
steps involved, 10-2 configuration files, 8-59
ser profiles (.ser) generation parameters, 8-65
converting to .class, 9-54 options, 8-59
generated profiles, 10-3 stored procedure calls, 5-45
Index-9
Index
streams translator (continued)

as function return values, 6-21 overview, 3-2, 4-36
as output parameters, 6-21 SQL semantics-checking and offline parsing,
classes and methods, 6-17 10-2
examples, 6-19 status messages, 10-11
general use in SQLJ, 6-10 support for alternative environments, 9-66
precautions, 6-14 test, 2-8
retrieving data, 6-15 type extensions, 6-22
sending data to database, 6-11 type resolution, expand search, 9-54
supporting classes, 6-9 types supported
strongly typed collections, 7-24 for JDBC 2.0, 6-6
strongly typed custom Java classes, 7-2 for Oracle8i, 6-9
strongly typed objects and references, 7-20 summary of types, 6-2
subclassing iterator classes, 8-38
summary option (Oracle customizer), A-29
Sun JDK
U
supported versions, 2-2 uninstall option (AuditorInstaller), A-42
support for global transactions, 8-18 update batching
support for pluggable databases, 8-25 batch limit, 11-10
synchronization of execution contexts, 8-28 batchable and compatible statements, 11-10
syntax batching incompatible statements, 11-10
translator command line, 9-10 canceling a batch, 11-10
translator properties files, 9-13 cautions, 11-10
system identifiers (SIDs) in connect strings, enabling and disabling, 11-10
deprecated, 2-7 error conditions during execution, 11-10
explicit and implicit batch execution, 11-10
T overview, 11-10
update counts, 11-10
TABLE syntax (nested tables), 7-25, 7-27 using implicit execution contexts, 11-10
TABLE type (PL/SQL), 6-8 with respect to recursive call-ins, 11-10
Thin driver (JDBC), 4-1 url option (customizer harness), A-14
transactions url option for checking (sqlj -url), 9-26
access mode settings, 8-46 URL, database
advanced transaction control, 8-45 default prefix for online checking, 9-26
automatic commit vs. manual commit, 4-22 SIDs deprecated, 2-7
basic transaction control, 4-21 use of database service names, 2-7
isolation level settings, 8-46 user option (customizer harness), A-13
JDBC Connection methods, 8-47 user option for checking (sqlj -user), 9-26
manual commit and rollback, 4-23 user-defined types, 7-16
modifying auto-commit, 4-23
overview, 4-21
savepoints for rollbacks, 4-25
V
specifying auto-commit, 4-22 VALUES syntax for stored functions, 5-46
translator VARRAYs
basic translation steps, 3-6 inserting a row, 7-30
code generation, 10-3 selecting into host expression, 7-29
compilation, 10-7 VARRAY types, 7-4
customization, 10-8 verbose option (customizer harness), A-12
error, warning, info messages, 10-9 verify option (customizer harness), A-17
exit codes, 10-12 version compatibility (Oracle customizer), A-20
globalization support, 10-15 version number options (sqlj -version-xxxx), 9-18
input and output, 3-8 VM
internal operations, 10-1 classpath option, 9-18
Java and SQLJ code-parsing, syntax- options through SQLJ, 9-51
checking, 10-1 specifying name, 9-66
Index-10
Index
vm option (sqlj -vm), 9-66 weakly typed custom Java classes, 7-2
weakly typed iterators, 8-38
WHERE CURRENT OF, 6-29
W WHERE CURRENT OF clause, 6-31
warn option (SQLCheckerCustomizer), A-35 Windows, SQLJ development in, 3-17
warn option (sqlj -warn), 9-35 WITH clause syntax, 5-5
warning messages, translator, 10-9 wrapper classes for null-handling, 4-16
warnings, translator, enabling/disabling, 9-35
weak object/collection types
restrictions, 7-38
support, 7-37
Index-11

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Oracle® Database

SQLJ Developer's Guide

Copyright © 1999, 2020, Oracle and/or its affiliates.

Primary Author: Apoorva Srinivas

1 Changes in This Release for Oracle SQLJ Developer’s Guide

4 Key Programming Considerations

7 Objects, Collections, and OPAQUE Types

8 Advanced Language Features

9 Translator Command Line and Options

10 Translator and Run-Time Functionality

11 Performance and Debugging

A Customization and Specialized Customizers

Access to Oracle Support

Convention Meaning Example

Convention Meaning Example

Conventions in Code Examples

Convention Meaning Example

Convention Meaning Example

capabilities, Oracle recommends that developers use explicit steps, such as

2.1 Assumptions and Requirements

2.1.1 Assumptions About Your Environment

• You can already run JDBC applications in your environment.

2.1.2 Requirements for Using the Oracle SQLJ Implementation

• Class files for the SQLJ run time.

2.1.3 SQLJ Environment

The following is a typical environment setup for Oracle-specific code generation:

2.1.4 Environment Considerations

2.1.5 SQLJ Backward Compatibility

2.2 Checking the Installation and Configuration

2.2.1 Check for Availability of SQLJ and Demo Applications

2.2.2 Check for Installed Directories and Files

Directories for JDBC

Directories for SQLJ

• demo (demo applications, including some referenced in this chapter)

2.2.3 Set the Path and Classpath

– To translate or run SQLJ programs in JDK 6 environment, you

2.2.4 Verify Installation of the sqljutl Package

This should result in a brief description of the package.

2.3 Testing the Setup

This section covers the following topics:

2.3.1 Set Up the Run-Time Connection

Connecting with an Oracle JDBC Driver

2.3.2 Create a Table to Verify the Database

2.3.3 Verify the JDBC Driver

The program should print:

2.3.4 Verify the SQLJ Translator and Run Time

Note that this command also compiles the application.

Now run the application as follows:

The program should print:

2.3.5 Verify the SQLJ Translator Connection to the Database

You can test online semantics-checking by translating the

% sqlj -user=HR TestInstallSQLJChecker.sqlj

If everything works, then the following line is displayed:

3.1 Overview of SQLJ

• SQL constructs, against a specified database schema to ensure consistency

3.2 Overview of SQLJ Components

3.2.1 SQLJ Translator Functionality

The translator produces a .java file.

3.2.2 SQLJ Run Time