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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <HTML ><HEAD ><TITLE >triggers</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK REV="MADE" HREF="mailto:pgsql-docs@postgresql.org"><LINK REL="HOME" TITLE="PostgreSQL 9.2.24 Documentation" HREF="index.html"><LINK REL="UP" TITLE="The Information Schema" HREF="information-schema.html"><LINK REL="PREVIOUS" TITLE="triggered_update_columns" HREF="infoschema-triggered-update-columns.html"><LINK REL="NEXT" TITLE="udt_privileges" HREF="infoschema-udt-privileges.html"><LINK REL="STYLESHEET" TYPE="text/css" HREF="stylesheet.css"><META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=ISO-8859-1"><META NAME="creation" CONTENT="2017-11-06T22:43:11"></HEAD ><BODY CLASS="SECT1" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="5" ALIGN="center" VALIGN="bottom" ><A HREF="index.html" >PostgreSQL 9.2.24 Documentation</A ></TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="top" ><A TITLE="triggered_update_columns" HREF="infoschema-triggered-update-columns.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="10%" ALIGN="left" VALIGN="top" ><A HREF="information-schema.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="60%" ALIGN="center" VALIGN="bottom" >Chapter 34. The Information Schema</TD ><TD WIDTH="20%" ALIGN="right" VALIGN="top" ><A TITLE="udt_privileges" HREF="infoschema-udt-privileges.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="SECT1" ><H1 CLASS="SECT1" ><A NAME="INFOSCHEMA-TRIGGERS" >34.54. <TT CLASS="LITERAL" >triggers</TT ></A ></H1 ><P > The view <TT CLASS="LITERAL" >triggers</TT > contains all triggers defined in the current database on tables and views that the current user owns or has some privilege other than <TT CLASS="LITERAL" >SELECT</TT > on. </P ><DIV CLASS="TABLE" ><A NAME="AEN51266" ></A ><P ><B >Table 34-52. <TT CLASS="LITERAL" >triggers</TT > Columns</B ></P ><TABLE BORDER="1" CLASS="CALSTABLE" ><COL><COL><COL><THEAD ><TR ><TH >Name</TH ><TH >Data Type</TH ><TH >Description</TH ></TR ></THEAD ><TBODY ><TR ><TD ><TT CLASS="LITERAL" >trigger_catalog</TT ></TD ><TD ><TT CLASS="TYPE" >sql_identifier</TT ></TD ><TD >Name of the database that contains the trigger (always the current database)</TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >trigger_schema</TT ></TD ><TD ><TT CLASS="TYPE" >sql_identifier</TT ></TD ><TD >Name of the schema that contains the trigger</TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >trigger_name</TT ></TD ><TD ><TT CLASS="TYPE" >sql_identifier</TT ></TD ><TD >Name of the trigger</TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >event_manipulation</TT ></TD ><TD ><TT CLASS="TYPE" >character_data</TT ></TD ><TD > Event that fires the trigger (<TT CLASS="LITERAL" >INSERT</TT >, <TT CLASS="LITERAL" >UPDATE</TT >, or <TT CLASS="LITERAL" >DELETE</TT >) </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >event_object_catalog</TT ></TD ><TD ><TT CLASS="TYPE" >sql_identifier</TT ></TD ><TD > Name of the database that contains the table that the trigger is defined on (always the current database) </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >event_object_schema</TT ></TD ><TD ><TT CLASS="TYPE" >sql_identifier</TT ></TD ><TD >Name of the schema that contains the table that the trigger is defined on</TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >event_object_table</TT ></TD ><TD ><TT CLASS="TYPE" >sql_identifier</TT ></TD ><TD >Name of the table that the trigger is defined on</TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >action_order</TT ></TD ><TD ><TT CLASS="TYPE" >cardinal_number</TT ></TD ><TD >Not yet implemented</TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >action_condition</TT ></TD ><TD ><TT CLASS="TYPE" >character_data</TT ></TD ><TD > <TT CLASS="LITERAL" >WHEN</TT > condition of the trigger, null if none (also null if the table is not owned by a currently enabled role) </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >action_statement</TT ></TD ><TD ><TT CLASS="TYPE" >character_data</TT ></TD ><TD > Statement that is executed by the trigger (currently always <TT CLASS="LITERAL" >EXECUTE PROCEDURE <TT CLASS="REPLACEABLE" ><I >function</I ></TT >(...)</TT >) </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >action_orientation</TT ></TD ><TD ><TT CLASS="TYPE" >character_data</TT ></TD ><TD > Identifies whether the trigger fires once for each processed row or once for each statement (<TT CLASS="LITERAL" >ROW</TT > or <TT CLASS="LITERAL" >STATEMENT</TT >) </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >action_timing</TT ></TD ><TD ><TT CLASS="TYPE" >character_data</TT ></TD ><TD > Time at which the trigger fires (<TT CLASS="LITERAL" >BEFORE</TT >, <TT CLASS="LITERAL" >AFTER</TT >, or <TT CLASS="LITERAL" >INSTEAD OF</TT >) </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >action_reference_old_table</TT ></TD ><TD ><TT CLASS="TYPE" >sql_identifier</TT ></TD ><TD >Applies to a feature not available in <SPAN CLASS="PRODUCTNAME" >PostgreSQL</SPAN ></TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >action_reference_new_table</TT ></TD ><TD ><TT CLASS="TYPE" >sql_identifier</TT ></TD ><TD >Applies to a feature not available in <SPAN CLASS="PRODUCTNAME" >PostgreSQL</SPAN ></TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >action_reference_old_row</TT ></TD ><TD ><TT CLASS="TYPE" >sql_identifier</TT ></TD ><TD >Applies to a feature not available in <SPAN CLASS="PRODUCTNAME" >PostgreSQL</SPAN ></TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >action_reference_new_row</TT ></TD ><TD ><TT CLASS="TYPE" >sql_identifier</TT ></TD ><TD >Applies to a feature not available in <SPAN CLASS="PRODUCTNAME" >PostgreSQL</SPAN ></TD ></TR ><TR ><TD ><TT CLASS="LITERAL" >created</TT ></TD ><TD ><TT CLASS="TYPE" >time_stamp</TT ></TD ><TD >Applies to a feature not available in <SPAN CLASS="PRODUCTNAME" >PostgreSQL</SPAN ></TD ></TR ></TBODY ></TABLE ></DIV ><P > Triggers in <SPAN CLASS="PRODUCTNAME" >PostgreSQL</SPAN > have two incompatibilities with the SQL standard that affect the representation in the information schema. First, trigger names are local to each table in <SPAN CLASS="PRODUCTNAME" >PostgreSQL</SPAN >, rather than being independent schema objects. Therefore there can be duplicate trigger names defined in one schema, so long as they belong to different tables. (<TT CLASS="LITERAL" >trigger_catalog</TT > and <TT CLASS="LITERAL" >trigger_schema</TT > are really the values pertaining to the table that the trigger is defined on.) Second, triggers can be defined to fire on multiple events in <SPAN CLASS="PRODUCTNAME" >PostgreSQL</SPAN > (e.g., <TT CLASS="LITERAL" >ON INSERT OR UPDATE</TT >), whereas the SQL standard only allows one. If a trigger is defined to fire on multiple events, it is represented as multiple rows in the information schema, one for each type of event. As a consequence of these two issues, the primary key of the view <TT CLASS="LITERAL" >triggers</TT > is really <TT CLASS="LITERAL" >(trigger_catalog, trigger_schema, event_object_table, trigger_name, event_manipulation)</TT > instead of <TT CLASS="LITERAL" >(trigger_catalog, trigger_schema, trigger_name)</TT >, which is what the SQL standard specifies. Nonetheless, if you define your triggers in a manner that conforms with the SQL standard (trigger names unique in the schema and only one event type per trigger), this will not affect you. </P ><DIV CLASS="NOTE" ><BLOCKQUOTE CLASS="NOTE" ><P ><B >Note: </B > Prior to <SPAN CLASS="PRODUCTNAME" >PostgreSQL</SPAN > 9.1, this view's columns <TT CLASS="STRUCTFIELD" >action_timing</TT >, <TT CLASS="STRUCTFIELD" >action_reference_old_table</TT >, <TT CLASS="STRUCTFIELD" >action_reference_new_table</TT >, <TT CLASS="STRUCTFIELD" >action_reference_old_row</TT >, and <TT CLASS="STRUCTFIELD" >action_reference_new_row</TT > were named <TT CLASS="STRUCTFIELD" >condition_timing</TT >, <TT CLASS="STRUCTFIELD" >condition_reference_old_table</TT >, <TT CLASS="STRUCTFIELD" >condition_reference_new_table</TT >, <TT CLASS="STRUCTFIELD" >condition_reference_old_row</TT >, and <TT CLASS="STRUCTFIELD" >condition_reference_new_row</TT > respectively. That was how they were named in the SQL:1999 standard. The new naming conforms to SQL:2003 and later. </P ></BLOCKQUOTE ></DIV ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="infoschema-triggered-update-columns.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="infoschema-udt-privileges.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><TT CLASS="LITERAL" >triggered_update_columns</TT ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="information-schema.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><TT CLASS="LITERAL" >udt_privileges</TT ></TD ></TR ></TABLE ></DIV ></BODY ></HTML >