Triggers

A trigger automatically runs a stored procedure when an UPDATE, DELETE, or INSERT command is run with a table. Since a trigger runs a stored procedure before the row that triggered it is updated, inserted, or deleted, you can cancel the update, insert, or delete with the ABORT TRIGGER command in the stored procedure. Also, you can verify the action being performed in an update trigger on the row by using a SELECT command with the WHERE CURRENT OF SYS_OLD/SYS_NEW syntax to check the row before/after the update.

Procedures run with triggers must be defined with no parameters. Triggers are added or dropped in the ALTER TABLE command. The TRIGGER option can also be used in the CREATE TABLE command. See the ALTER TABLE and CREATE TABLE entries for the correct syntax.


To List Triggers

To list all the tables in the open database that have triggers and the triggers, use the following syntax:

   LIST TRIGGER

To list triggers for a specified table, use the following syntax:

   LIST TRIGGER tblname