postgres/doc/src/sgml/ref/execute.sgml

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PostgreSQL documentation
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<refentry id="SQL-EXECUTE">
 <refmeta>
  <refentrytitle id="sql-execute-title">EXECUTE</refentrytitle>
  <refmiscinfo>SQL - Language Statements</refmiscinfo>
 </refmeta>
 <refnamediv>
  <refname>
   EXECUTE
  </refname>
  <refpurpose>
   execute a prepared query
  </refpurpose>
 </refnamediv>
 <refsynopsisdiv>
  <refsynopsisdivinfo>
   <date>2002-08-12</date>
  </refsynopsisdivinfo>
  <synopsis>
   EXECUTE <replaceable class="PARAMETER">plan_name</replaceable> [ (<replaceable class="PARAMETER">parameter</replaceable> [, ...] ) ] [ INTO [ TEMPORARY | TEMP ] <replaceable class="PARAMETER">table</replaceable> ]
  </synopsis>

  <refsect2 id="R2-SQL-EXECUTE-1">
   <refsect2info>
    <date>2002-08-12</date>
   </refsect2info>
   <title>
    Inputs
   </title>

   <para>
    <variablelist>
     <varlistentry>
      <term><replaceable class="PARAMETER">plan_name</replaceable></term>
      <listitem>
       <para>
		The name of the prepared query to execute.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry>
      <term><replaceable class="PARAMETER">parameter</replaceable></term>
      <listitem>
       <para>
		The actual value of a parameter to the prepared query.  This
		must be an expression yielding a value of a type compatible
		with the data-type specified for this parameter position in
		the <command>PREPARE</command> statement that created the
		prepared query.
       </para>
      </listitem>
     </varlistentry>

     <varlistentry>
      <term><replaceable class="PARAMETER">table</replaceable></term>
      <listitem>
       <para>
        The name of the table in which to store the results of
        executing the query (if it is a <command>SELECT</command>). If
        no table is specified, the results are returned to the client
        (as normal).
       </para>
      </listitem>
     </varlistentry>
    </variablelist>
   </para>
  </refsect2>
 </refsynopsisdiv>

 <refsect1 id="R1-SQL-EXECUTE-1">
  <refsect1info>
   <date>2002-08-12</date>
  </refsect1info>
  <title>
   Description
  </title>

  <para>
   <command>EXECUTE</command> is used to execute a previously prepared
   query. Since prepared queries only exist for the duration of a
   session, the prepared query must have been created by a
   <command>PREPARE</command> statement executed earlier in the
   current session.
  </para>

  <para>
   If the <command>PREPARE</command> statement that created the query
   specified some parameters, a compatible set of parameters must be
   passed to the <command>EXECUTE</command> statement, or else an
   error is raised. Note that (unlike functions) prepared queries are
   not overloaded based on the type or number of their parameters: the
   name of a prepared query must be unique within a database session.
  </para>

  <para>
   Like <command>SELECT INTO</command>, <command>EXECUTE</command> can
   store the results of executing the query into a newly-created
   table, by specifying an INTO clause. For more information on this behavior,
   see <xref linkend="sql-selectinto" endterm="sql-selectinto-title">.
  </para>

  <para>
   For more information on the creation and usage of prepared queries,
   see <xref linkend="sql-prepare" endterm="sql-prepare-title">.
  </para>
 </refsect1>

 <refsect1 id="R1-SQL-EXECUTE-2">
  <title>
   Compatibility
  </title>

  <refsect2 id="R2-SQL-EXECUTE-2">
   <refsect2info>
    <date>2002-08-12</date>
   </refsect2info>
   <title>
    SQL92
   </title>
   <para>
	SQL92 includes an <command>EXECUTE</command> statement, but it is
    only for use in embedded SQL clients. The
    <command>EXECUTE</command> statement implemented by
    <productname>PostgreSQL</productname> also uses a somewhat
    different syntax.
   </para>
  </refsect2>
 </refsect1>
</refentry>

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