CREATE CONSTRAINT TRIGGER

Section: SQL Commands (7)
Updated: 2012-08-14
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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 containing 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 foreign-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 constraint 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.

This document was created by man2html, using the manual pages.
Time: 05:34:14 GMT, December 24, 2015