Support for triggers differs as follows:
SQL Anywhere supports both row-level and statement-level triggers.
Adaptive Server Enterprise supports only statement-level triggers.
Sybase IQ does not support triggers.
A trigger is effectively a stored procedure that is
run automatically either immediately before or immediately after
an INSERT, UPDATE, or DELETE as
part of the same transaction, that can be used to cause a dependent
change (for example, to automatically update the name of an employee’s
manager when the employee is moved to a different department). It
can also be used to write an audit trail to identify which modifications
made which changes to the database, and at what time.
