PREPARE

Function

PREPARE creates a prepared statement.

A prepared statement is a performance optimizing object on the server. When the PREPARE statement is executed, the specified query is parsed, analyzed, and rewritten. When EXECUTE is executed, the prepared statement is planned and executed. This avoids repetitive parsing and analysis. After the PREPARE statement is created, it exists throughout the database session. Once it is created (even if in a transaction block), it will not be deleted when a transaction is rolled back. It can only be deleted by explicitly invoking DEALLOCATE or automatically deleted when the session ends.

Precautions

None

Syntax

PREPARE name [ ( data_type [, ...] ) ] AS statement;

Parameter Description

• name

  Specifies the name of a prepared statement. It must be unique in the session.

• data_type

  Specifies the type of an argument.

• statement

  Specifies a SELECT, INSERT, UPDATE, DELETE, MERGE INTO, or VALUES statement.

Examples

See Examples in EXECUTE.