Java Programming with Oracle SQLJ

8.2. Execution Contexts

A SQLJ executable statement contains an embedded SQL statement, which is said to run within an execution context. Each SQLJ executable statement uses an execution context that is either implicitly or explicitly associated with it. An execution context is an object of the class sqlj.runtime.ExecutionContext. The ExecutionContext class provides a number of useful methods that you can use to control how the SQL statement is run. You can also use these methods to get information on the results of the previously executed SQL statement, and to enable batch processing (see Chapter 10 for details on batch processing).

Execution contexts are also used in multithreaded SQLJ applications, as you will see later in this chapter. An execution context should not be confused with a connection context: a connection context is used to specify a connection to a database; an execution context is used to run a SQL statement. I know all this may sound confusing, but it will make more sense once you look at some examples.

8.2.1. The Default Execution Context

A default execution context is created for every connection context. When you create a default connection context via a call to the Oracle.connect( ) method, a default execution context is also created. Therefore, if you create five connection contexts, you will also get five execution contexts.

No special effort on your part is required to use a connection's default execution context when executing a SQL statement. For ...