Sends a query for optimization prior to execution.
Call Prepare to allocate resources for the query and to perform additional optimizations. Calling Prepare before executing a query improves application performance.
Delphi automatically prepares a query if it is executed without first being prepared. After execution, Delphi unprepares the query. When a query will be executed a number of times, an application should always explicitly prepare the query to avoid multiple and unnecessary prepares and unprepares.
Preparing a query consumes some database resources, so it is good practice for an application to unprepare a query once it is done using it. The UnPrepare method unprepares a query.
When you change the text of a query at runtime, the query is automatically closed and unprepared.