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
name
The name of the new trigger.
table
The name of the table with which the trigger will be associated.
event
The 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.
function
The 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
; theopaque
type is used only by internal functions and such functions cannot be invoked directly from SQL.arguments
The arguments to pass to the
function
when the trigger is called.
Results
CREATE
The 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
âfiresâ the trigger, the function you
specified will be executed.
Note
A trigger may only be created on a table by the tableâs 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 ...
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