Create Trigger
Creates a new trigger.
Synopsis
CREATE TRIGGER name { BEFORE | AFTER } { event [ OR event ... ] } ON table FOR EACH { ROW | STATEMENT } EXECUTE PROCEDURE function ( arguments )
Parameters
nameThe name of the new trigger.
tableThe name of the table with which the trigger will be associated.
eventThe event with which you wish to associate the trigger, that causes the trigger to fire. Valid events are: INSERT, DELETE, and UPDATE. A trigger may be associated with more than one event.
functionThe name of the function you wish to link to the new trigger. When the trigger fires, the function is invoked. The function must return a variable of type
opaque; theopaquetype is used only by internal functions and such functions cannot be invoked directly from SQL.argumentsThe arguments to pass to the
functionwhen the trigger is called.
Results
CREATEThe message returned when a trigger is successfully created.
Description
Use the CREATE TRIGGER command to add a trigger to a database. When a
trigger is added to the database, it is associated with the table specified in the ON clause. When the specified
event “fires” the trigger, the function you
specified will be executed.
Note
A trigger may only be created on a table by the table’s owner, or by a superuser.
When you create a trigger, you must specify whether it is to be fired before or after the
event is attempted (or completed). If the trigger ...