Allocates, opens, and parses cursor for a query.
procedure Prepare; override;
Call the Prepare method to allocate, open, and parse cursor for a query. Calling Prepare before executing a query improves application performance.
SQL statements which have output parameters and aren't stored procedures calls or some of system functions such as sp_setapprole, should be executed without prior call to the Prepare method.
The UnPrepare method unprepares a query.
Note: When you change the text of a query at runtime, the query is automatically closed and unprepared.