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$PostgreSQL: pgsql/doc/src/sgml/ref/create_constraint.sgml,v 1.15 2006/10/1619:30:09 momjian Exp $

PostgreSQL documentation

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<refsynopsisdiv>

<synopsis>

CREATE CONSTRAINT TRIGGER <replaceable class="parameter">name</replaceable>

AFTER <replaceable class="parameter">events</replaceable> ON

<replaceable class="parameter">tablename</replaceable> <replaceable class="parameter">constraint</replaceable> <replaceable class="parameter">attributes</replaceable>

FOR EACH ROW EXECUTE PROCEDURE <replaceable class="parameter">funcname</replaceable> ( <replaceable class="parameter">args</replaceable> )

AFTER <replaceable class="parameter">event [ OR ... ]</replaceable>

ON <replaceable class="parameter">table_name</replaceable>

[ FROM <replaceable class="parameter">referenced_table_name</replaceable> ]

{ NOT DEFERRABLE | [ DEFERABBLE ] { INITIALLY IMMEDIATE | INITIALLY DEFERRED } }

FOR EACH ROW

EXECUTE PROCEDURE <replaceable class="parameter">funcname</replaceable> ( <replaceable class="parameter">arguments</replaceable> )

</synopsis>

</refsynopsisdiv>

<para>

<command>CREATE CONSTRAINT TRIGGER</command> is used within

<command>CREATE TABLE</command>/<command>ALTER TABLE</command> and by

<application>pg_dump</application> to create the special triggers for

referential integrity.

It is not intended for general use.

</para>

</refsect1>

<application>pg_dump</application> to create the special triggers for

referential integrity.

It is not intended for general use.

</para>

</refsect1>

<refsect1>

<title>Parameters</title>

<variablelist>

<varlistentry>

<term><replaceable class="PARAMETER">name</replaceable></term>

<listitem>

<para>

The name of the constraint trigger. The actual name of the

created trigger will be of the form

<literal>RI_ConstraintTrigger_0000<literal> (where 0000 is some number

assigned by the server).

Use this assigned name is when dropping the constraint.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><replaceable class="PARAMETER">events</replaceable></term>

<listitem>

<para>

One of <literal>INSERT</literal>, <literal>UPDATE</literal>, or

<literal>DELETE</literal>; this specifies the event that will fire the

trigger. Multiple events can be specified using <literal>OR<literal>.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><replaceable class="PARAMETER">table_name</replaceable></term>

<listitem>

<para>

The (possibly schema-qualified) name of the table in which

the triggering events occur.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><replaceable class="PARAMETER">referenced_table_name</replaceable></term>

<listitem>

<para>

The (possibly schema-qualified) name of the table referenced by the

constraint. Used by foreign key constraints triggers.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><literal>DEFERRABLE</literal></term>

<term><literal>NOT DEFERRABLE</literal></term>

<term><literal>INITIALLY IMMEDIATE</literal></term>

<term><literal>INITIALLY DEFERRED</literal></term>

<listitem>

<para>

See the <xref linkend="SQL-CREATETABLE" endterm="SQL-CREATETABLE-TITLE">

documentation for details of these constraint options.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><replaceable class="PARAMETER">funcname</replaceable>(<replaceable class="PARAMETER">args</replaceable>)</term>

<listitem>

<para>

The function to call as part of the trigger processing. See <xref

linkend="SQL-CREATETRIGGER" endterm="SQL-CREATETRIGGER-TITLE"> for

details.

</para>

</listitem>

</varlistentry>

</variablelist>

</refsect1>

<refsect1>

<title>Parameters</title>

<variablelist>

<varlistentry>

<term><replaceable class="PARAMETER">name</replaceable></term>

<listitem>

<para>

The name of the constraint trigger.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><replaceable class="PARAMETER">events</replaceable></term>

<listitem>

<para>

The event categories for which this trigger should be fired.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><replaceable class="PARAMETER">tablename</replaceable></term>

<listitem>

<para>

The name (possibly schema-qualified) of the table in which

the triggering events occur.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><replaceable class="PARAMETER">constraint</replaceable></term>

<listitem>

<para>

Actual constraint specification.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><replaceable class="PARAMETER">attributes</replaceable></term>

<listitem>

<para>

The constraint attributes.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><replaceable class="PARAMETER">funcname</replaceable>(<replaceable class="PARAMETER">args</replaceable>)</term>

<listitem>

<para>

The function to call as part of the trigger processing.

</para>

</listitem>

</varlistentry>

</variablelist>

<title>Compatibility</title>

<para>

<command>CREATE CONTRAINT TRIGGER</command> is a

<productname>PostgreSQL</productname> extension of the <acronym>SQL</>

standard.

</para>

</refsect1>

</refentry>

</refentry>