3
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
4
<title>30.37.�triggers</title>
5
<link rel="stylesheet" href="stylesheet.css" type="text/css">
6
<link rev="made" href="pgsql-docs@postgresql.org">
7
<meta name="generator" content="DocBook XSL Stylesheets V1.64.1">
8
<link rel="home" href="index.html" title="PostgreSQL 8.0.0beta5 Documentation">
9
<link rel="up" href="information-schema.html" title="Chapter�30.�The Information Schema">
10
<link rel="previous" href="infoschema-tables.html" title="30.36.�tables">
11
<link rel="next" href="infoschema-usage-privileges.html" title="30.38.�usage_privileges">
13
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="sect1" lang="en">
14
<div class="titlepage">
15
<div><div><h2 class="title" style="clear: both">
16
<a name="infoschema-triggers"></a>30.37.�<tt class="literal">triggers</tt></h2></div></div>
19
<p> The view <tt class="literal">triggers</tt> contains all triggers defined
20
in the current database that are owned by the current user. (The
21
owner of the table is the owner of the trigger.)
24
<a name="id2628070"></a><p class="title"><b>Table�30.35.�<tt class="literal">triggers</tt> Columns</b></p>
25
<table summary="triggers Columns" border="1">
38
<td><tt class="literal">trigger_catalog</tt></td>
39
<td><tt class="type">sql_identifier</tt></td>
40
<td>Name of the database that contains the trigger (always the current database)</td>
43
<td><tt class="literal">trigger_schema</tt></td>
44
<td><tt class="type">sql_identifier</tt></td>
45
<td>Name of the schema that contains the trigger</td>
48
<td><tt class="literal">trigger_name</tt></td>
49
<td><tt class="type">sql_identifier</tt></td>
50
<td>Name of the trigger</td>
53
<td><tt class="literal">event_manipulation</tt></td>
54
<td><tt class="type">character_data</tt></td>
55
<td> Event that fires the trigger (<tt class="literal">INSERT</tt>,
56
<tt class="literal">UPDATE</tt>, or <tt class="literal">DELETE</tt>)
60
<td><tt class="literal">event_object_catalog</tt></td>
61
<td><tt class="type">sql_identifier</tt></td>
62
<td> Name of the database that contains the table that the trigger
63
is defined on (always the current database)
67
<td><tt class="literal">event_object_schema</tt></td>
68
<td><tt class="type">sql_identifier</tt></td>
69
<td>Name of the schema that contains the table that the trigger is defined on</td>
72
<td><tt class="literal">event_object_name</tt></td>
73
<td><tt class="type">sql_identifier</tt></td>
74
<td>Name of the table that the trigger is defined on</td>
77
<td><tt class="literal">action_order</tt></td>
78
<td><tt class="type">cardinal_number</tt></td>
79
<td>Not yet implemented</td>
82
<td><tt class="literal">action_condition</tt></td>
83
<td><tt class="type">character_data</tt></td>
84
<td>Applies to a feature not available in <span class="productname">PostgreSQL</span>
88
<td><tt class="literal">action_statement</tt></td>
89
<td><tt class="type">character_data</tt></td>
90
<td> Statement that is executed by the trigger (currently always
91
<tt class="literal">EXECUTE PROCEDURE
92
<i class="replaceable"><tt>function</tt></i>(...)</tt>)
96
<td><tt class="literal">action_orientation</tt></td>
97
<td><tt class="type">character_data</tt></td>
98
<td> Identifies whether the trigger fires once for each processed
99
row or once for each statement (<tt class="literal">ROW</tt> or
100
<tt class="literal">STATEMENT</tt>)
104
<td><tt class="literal">condition_timing</tt></td>
105
<td><tt class="type">character_data</tt></td>
106
<td> Time at which the trigger fires (<tt class="literal">BEFORE</tt> or
107
<tt class="literal">AFTER</tt>)
111
<td><tt class="literal">condition_reference_old_table</tt></td>
112
<td><tt class="type">sql_identifier</tt></td>
113
<td>Applies to a feature not available in <span class="productname">PostgreSQL</span>
117
<td><tt class="literal">condition_reference_new_table</tt></td>
118
<td><tt class="type">sql_identifier</tt></td>
119
<td>Applies to a feature not available in <span class="productname">PostgreSQL</span>
125
<p> Triggers in <span class="productname">PostgreSQL</span> have two
126
incompatibilities with the SQL standard that affect the
127
representation in the information schema. First, trigger names are
128
local to the table in <span class="productname">PostgreSQL</span>, rather
129
than independent schema objects. Therefore there may be duplicate
130
trigger names defined in one schema, as long as they belong to
131
different tables. (<tt class="literal">trigger_catalog</tt> and
132
<tt class="literal">trigger_schema</tt> are really the values pertaining
133
to the table that the trigger is defined on.) Second, triggers can
134
be defined to fire on multiple events in
135
<span class="productname">PostgreSQL</span> (e.g., <tt class="literal">ON INSERT OR
136
UPDATE</tt>), whereas the SQL standard only allows one. If a
137
trigger is defined to fire on multiple events, it is represented as
138
multiple rows in the information schema, one for each type of
139
event. As a consequence of these two issues, the primary key of
140
the view <tt class="literal">triggers</tt> is really
141
<tt class="literal">(trigger_catalog, trigger_schema, trigger_name,
142
event_object_name, event_manipulation)</tt> instead of
143
<tt class="literal">(trigger_catalog, trigger_schema, trigger_name)</tt>,
144
which is what the SQL standard specifies. Nonetheless, if you
145
define your triggers in a manner that conforms with the SQL
146
standard (trigger names unique in the schema and only one event
147
type per trigger), this will not affect you.
added
removed
docs/en_US/pg/infoschema-triggers.html
