CREATE CONSTRAINT TRIGGER(7)                              SQL Commands                              CREATE CONSTRAINT TRIGGER(7)



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 creates a constraint trigger. This is the same as a regular trigger except that the timing of
       the trigger firing can be adjusted using SET CONSTRAINTS [set_constraints(7)].  Constraint triggers  must  be  AFTER  ROW
       triggers.  They  can  be fired either at the end of the statement causing the triggering event, or at the end of the con-
       taining transaction; in the latter case they are said to be deferred. A  pending  deferred-trigger  firing  can  also  be
       forced to happen immediately by using SET CONSTRAINTS.

PARAMETERS
       name   The  name  of the constraint trigger. This is also the name to use when modifying the trigger's behavior using SET
              CONSTRAINTS.  The name cannot be schema-qualified -- the trigger inherits the schema of its table.

       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 another table referenced by the constraint. This option is used for for-
              eign-key constraints and is not recommended for general use.

       DEFERRABLE

       NOT DEFERRABLE

       INITIALLY IMMEDIATE

       INITIALLY DEFERRED
              The default timing of the trigger.  See the CREATE TABLE [create_table(7)] documentation for details of these con-
              straint options.

       funcname
              The function to call when the trigger is fired. See CREATE TRIGGER [create_trigger(7)] for details.

       arguments
              Optional argument strings to pass to the trigger function. See CREATE TRIGGER [create_trigger(7)] for details.

COMPATIBILITY
       CREATE CONSTRAINT TRIGGER is a PostgreSQL extension of the SQL standard.

SEE ALSO
       CREATE TRIGGER [create_trigger(7)], DROP TRIGGER [drop_trigger(7)], SET CONSTRAINTS [set_constraints(7)]



SQL - Language Statements                                  2011-09-22                               CREATE CONSTRAINT TRIGGER(7)