blob: b04b86c8887b6a0b1102206729560c5b294a9a99 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
|
<!--
$Header: /cvsroot/pgsql/doc/src/sgml/ref/delete.sgml,v 1.17 2003/04/26 23:56:51 petere Exp $
PostgreSQL documentation
-->
<refentry id="SQL-DELETE">
<refmeta>
<refentrytitle id="SQL-DELETE-TITLE">DELETE</refentrytitle>
<refmiscinfo>SQL - Language Statements</refmiscinfo>
</refmeta>
<refnamediv>
<refname>DELETE</refname>
<refpurpose>delete rows of a table</refpurpose>
</refnamediv>
<refsynopsisdiv>
<synopsis>
DELETE FROM [ ONLY ] <replaceable class="PARAMETER">table</replaceable> [ WHERE <replaceable class="PARAMETER">condition</replaceable> ]
</synopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para>
<command>DELETE</command> deletes rows that satisfy the
<literal>WHERE</literal> clause from the specified table. If the
<literal>WHERE</literal> clause is absent, the effect is to delete
all rows in the table. The result is a valid, but empty table.
</para>
<tip>
<para>
<xref linkend="sql-truncate" endterm="sql-truncate-title"> is a
<productname>PostgreSQL</productname> extension which provides a
faster mechanism to remove all rows from a table.
</para>
</tip>
<para>
By default, <command>DELETE</command> will delete rows in the
specified table and all its subtables. If you wish to only delete
from the specific table mentioned, you must use the
<literal>ONLY</literal> clause.
</para>
<para>
You must have the <literal>DELETE</literal> privilege on the table
to delete from it, as well as the <literal>SELECT</literal>
privilege to any table whose values are read in the <replaceable
class="parameter">condition</replaceable>.
</para>
</refsect1>
<refsect1>
<title>Parameters</title>
<variablelist>
<varlistentry>
<term><replaceable class="parameter">table</replaceable></term>
<listitem>
<para>
The name (optionally schema-qualified) of an existing table.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><replaceable class="parameter">condition</replaceable></term>
<listitem>
<para>
A value expression that returns a value of type
<type>boolean</type> that determines the rows which are to be
deleted.
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Diagnostics</title>
<variablelist>
<varlistentry>
<term><computeroutput>DELETE <replaceable class="parameter">count</replaceable></computeroutput></term>
<listitem>
<para>
Message returned if rows are successfully deleted. The
<replaceable class="parameter">count</replaceable> is the number
of rows deleted. If <replaceable
class="parameter">count</replaceable> is 0, no rows were
deleted.
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Examples</title>
<para>
Delete all films but musicals:
<programlisting>
DELETE FROM films WHERE kind <> 'Musical';
</programlisting>
</para>
<para>
Clear the table <literal>films</literal>:
<programlisting>
DELETE FROM films;
</programlisting>
</para>
</refsect1>
<refsect1>
<title>Compatibility</title>
<para>
This command conforms to the SQL standard.
</para>
</refsect1>
</refentry>
<!-- Keep this comment at the end of the file
Local variables:
mode: sgml
sgml-omittag:nil
sgml-shorttag:t
sgml-minimize-attributes:nil
sgml-always-quote-attributes:t
sgml-indent-step:1
sgml-indent-data:t
sgml-parent-document:nil
sgml-default-dtd-file:"../reference.ced"
sgml-exposed-tags:nil
sgml-local-catalogs:"/usr/lib/sgml/catalog"
sgml-local-ecat-files:nil
End:
-->
|
