6 Queries

Queries are a key element to any Oracle Application Server TopLink application, because they enable OracleAS TopLink to manage persistent data on the database. The query framework that OracleAS TopLink provides gives you the flexibility you need to manage the complex persistence requirements of enterprise applications.

The OracleAS TopLink query framework offers the following key features:

• A rich set of query types that enable you to query for objects, object summaries, and data

• Flexible search criteria, including support for query by example, stored procedures, OracleAS TopLink expressions, Structured Query Language (SQL), and Enterprise JavaBean Query Language (EJB QL)

• Configuration options that enable you to customize query execution, and optimize query performance

To define OracleAS TopLink queries, use OracleAS TopLink Mapping Workbench, the OracleAS TopLink API, or, in the case of entity beans, EJB Finders.

This chapter introduces OracleAS TopLink queries, and includes discussions on:

• Introduction to Query Concepts

• Query Building Basics

• Executing Queries

• Query Results

• Queries and the Cache

• Query Objects and Write Operations

• Query Object Performance Options

• Oracle Extension Support

• Advanced Querying

• EJB Finders

• Exception Handling

• Introduction to Query Concepts

• Query Building Basics

• Executing Queries

• Query Results

• Queries and the Cache

• Custom Platforms

• Query Object Performance Options

• Oracle Extension Support

• Advanced Querying

• EJB Finders

• Exception Handling

• Introduction to Query Concepts

• Query Building Basics

• Executing Queries

• Query Results

• Queries and the Cache

• Custom Platforms

• Query Object Performance Options

• Oracle Extension Support

• Advanced Querying

• EJB Finders

• Exception Handling