1<!--
2doc/src/sgml/ref/execute.sgml
3PostgreSQL documentation
4-->
5
6<refentry id="sql-execute">
7 <indexterm zone="sql-execute">
8  <primary>EXECUTE</primary>
9 </indexterm>
10
11 <indexterm zone="sql-execute">
12  <primary>prepared statements</primary>
13  <secondary>executing</secondary>
14 </indexterm>
15
16 <refmeta>
17  <refentrytitle>EXECUTE</refentrytitle>
18  <manvolnum>7</manvolnum>
19  <refmiscinfo>SQL - Language Statements</refmiscinfo>
20 </refmeta>
21
22 <refnamediv>
23  <refname>EXECUTE</refname>
24  <refpurpose>execute a prepared statement</refpurpose>
25 </refnamediv>
26
27 <refsynopsisdiv>
28<synopsis>
29EXECUTE <replaceable class="parameter">name</replaceable> [ ( <replaceable class="parameter">parameter</replaceable> [, ...] ) ]
30</synopsis>
31 </refsynopsisdiv>
32
33 <refsect1>
34  <title>Description</title>
35
36  <para>
37   <command>EXECUTE</command> is used to execute a previously prepared
38   statement. Since prepared statements only exist for the duration of a
39   session, the prepared statement must have been created by a
40   <command>PREPARE</command> statement executed earlier in the
41   current session.
42  </para>
43
44  <para>
45   If the <command>PREPARE</command> statement that created the statement
46   specified some parameters, a compatible set of parameters must be
47   passed to the <command>EXECUTE</command> statement, or else an
48   error is raised. Note that (unlike functions) prepared statements are
49   not overloaded based on the type or number of their parameters; the
50   name of a prepared statement must be unique within a database session.
51  </para>
52
53  <para>
54   For more information on the creation and usage of prepared statements,
55   see <xref linkend="sql-prepare"/>.
56  </para>
57 </refsect1>
58
59 <refsect1>
60  <title>Parameters</title>
61
62  <variablelist>
63   <varlistentry>
64    <term><replaceable class="parameter">name</replaceable></term>
65    <listitem>
66     <para>
67      The name of the prepared statement to execute.
68     </para>
69    </listitem>
70   </varlistentry>
71
72   <varlistentry>
73    <term><replaceable class="parameter">parameter</replaceable></term>
74    <listitem>
75     <para>
76      The actual value of a parameter to the prepared statement.  This
77      must be an expression yielding a value that is compatible with
78      the data type of this parameter, as was determined when the
79      prepared statement was created.
80     </para>
81    </listitem>
82   </varlistentry>
83  </variablelist>
84 </refsect1>
85
86 <refsect1>
87  <title>Outputs</title>
88   <para>
89   The command tag returned by <command>EXECUTE</command>
90   is that of the prepared statement, and not <literal>EXECUTE</literal>.
91  </para>
92 </refsect1>
93
94 <refsect1>
95  <title>Examples</title>
96  <para>
97    Examples are given in <xref linkend="sql-prepare-examples"/>
98    in the <xref linkend="sql-prepare"/> documentation.
99   </para>
100 </refsect1>
101
102 <refsect1>
103  <title>Compatibility</title>
104
105  <para>
106   The SQL standard includes an <command>EXECUTE</command> statement,
107   but it is only for use in embedded SQL.  This version of the
108   <command>EXECUTE</command> statement also uses a somewhat different
109   syntax.
110  </para>
111 </refsect1>
112
113 <refsect1>
114  <title>See Also</title>
115
116  <simplelist type="inline">
117   <member><xref linkend="sql-deallocate"/></member>
118   <member><xref linkend="sql-prepare"/></member>
119  </simplelist>
120 </refsect1>
121</refentry>
122