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12.31 CREATE CONSTRAINT TRIGGER

Name

CREATE CONSTRAINT TRIGGER -- define a new constraint trigger

Synopsis

CREATE CONSTRAINT TRIGGER name
    AFTER event [ OR ... ]
    ON table_name
    [ FROM referenced_table_name ]
    { NOT DEFERRABLE | [ DEFERRABLE ] { INITIALLY IMMEDIATE |
 INITIALLY DEFERRED } }
    FOR EACH ROW
    EXECUTE PROCEDURE funcname ( arguments )

Description

CREATE CONSTRAINT TRIGGER is used within CREATE TABLE/ALTER TABLE and by pg_dump to create the special triggers for referential integrity. It is not intended for general use.

Parameters

name

The name of the constraint trigger. The actual name of the created trigger will be of the form RI_ConstraintTrigger_0000 (where 0000 is some number assigned by the server). Use this assigned name when dropping the trigger.

event

One of INSERT, UPDATE, or DELETE; this specifies the event that will fire the trigger. Multiple events can be specified using OR.

table_name

The (possibly schema-qualified) name of the table in which the triggering events occur.

referenced_table_name

The (possibly schema-qualified) name of the table referenced by the constraint. Used by foreign key constraints triggers.

DEFERRABLE

NOT DEFERRABLE

INITIALLY IMMEDIATE

INITIALLY DEFERRED

See the CREATE TABLE documentation for details of these constraint options.

funcname(args)

The function to call as part of the trigger processing. See CREATE TRIGGER for details.

Compatibility

CREATE CONTRAINT TRIGGER is a PostgreSQL extension of the SQL standard.