doc/src/sgml/ref/select_into.sgml

<!--
doc/src/sgml/ref/select_into.sgml
PostgreSQL documentation
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<refentry id="sql-selectinto">
 <indexterm zone="sql-selectinto">
  <primary>SELECT INTO</primary>
 </indexterm>

 <refmeta>
  <refentrytitle>SELECT INTO</refentrytitle>
  <manvolnum>7</manvolnum>
  <refmiscinfo>SQL - Language Statements</refmiscinfo>
 </refmeta>

 <refnamediv>
  <refname>SELECT INTO</refname>
  <refpurpose>define a new table from the results of a query</refpurpose>
 </refnamediv>

 <refsynopsisdiv>
<synopsis>
[ WITH [ RECURSIVE ] <replaceable class="parameter">with_query</replaceable> [, ...] ]
SELECT [ ALL | DISTINCT [ ON ( <replaceable class="parameter">expression</replaceable> [, ...] ) ] ]
    * | <replaceable class="parameter">expression</replaceable> [ [ AS ] <replaceable class="parameter">output_name</replaceable> ] [, ...]
    INTO [ TEMPORARY | TEMP | UNLOGGED ] [ TABLE ] <replaceable class="parameter">new_table</replaceable>
    [ FROM <replaceable class="parameter">from_item</replaceable> [, ...] ]
    [ WHERE <replaceable class="parameter">condition</replaceable> ]
    [ GROUP BY <replaceable class="parameter">expression</replaceable> [, ...] ]
    [ HAVING <replaceable class="parameter">condition</replaceable> ]
    [ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceable class="parameter">window_definition</replaceable> ) [, ...] ]
    [ { UNION | INTERSECT | EXCEPT } [ ALL | DISTINCT ] <replaceable class="parameter">select</replaceable> ]
    [ ORDER BY <replaceable class="parameter">expression</replaceable> [ ASC | DESC | USING <replaceable class="parameter">operator</replaceable> ] [ NULLS { FIRST | LAST } ] [, ...] ]
    [ LIMIT { <replaceable class="parameter">count</replaceable> | ALL } ]
    [ OFFSET <replaceable class="parameter">start</replaceable> [ ROW | ROWS ] ]
    [ FETCH { FIRST | NEXT } [ <replaceable class="parameter">count</replaceable> ] { ROW | ROWS } ONLY ]
    [ FOR { UPDATE | SHARE } [ OF <replaceable class="parameter">table_name</replaceable> [, ...] ] [ NOWAIT ] [...] ]
</synopsis>
 </refsynopsisdiv>

 <refsect1>
  <title>Description</title>

  <para>
   <command>SELECT INTO</command> creates a new table and fills it
   with data computed by a query.  The data is not returned to the
   client, as it is with a normal <command>SELECT</command>.  The new
   table's columns have the names and data types associated with the
   output columns of the <command>SELECT</command>.
  </para>
 </refsect1>

 <refsect1>
  <title>Parameters</title>

  <variablelist>
  <varlistentry>
   <term><literal>TEMPORARY</literal> or <literal>TEMP</literal></term>
   <listitem>
    <para>
     If specified, the table is created as a temporary table.  Refer
     to <xref linkend="sql-createtable"/> for details.
    </para>
   </listitem>
  </varlistentry>

  <varlistentry>
   <term><literal>UNLOGGED</literal></term>
   <listitem>
    <para>
     If specified, the table is created as an unlogged table.  Refer
     to <xref linkend="sql-createtable"/> for details.
    </para>
   </listitem>
  </varlistentry>

   <varlistentry>
    <term><replaceable class="parameter">new_table</replaceable></term>
    <listitem>
     <para>
      The name (optionally schema-qualified) of the table to be created.
     </para>
    </listitem>
   </varlistentry>
  </variablelist>

  <para>
   All other parameters are described in detail under <xref
   linkend="sql-select"/>.
  </para>
 </refsect1>

 <refsect1>
  <title>Notes</title>

  <para>
   <link linkend="sql-createtableas"><command>CREATE TABLE AS</command></link> is functionally similar to
   <command>SELECT INTO</command>.  <command>CREATE TABLE AS</command>
   is the recommended syntax, since this form of <command>SELECT
   INTO</command> is not available in <application>ECPG</application>
   or <application>PL/pgSQL</application>, because they interpret the
   <literal>INTO</literal> clause differently. Furthermore,
   <command>CREATE TABLE AS</command> offers a superset of the
   functionality provided by <command>SELECT INTO</command>.
  </para>

  <para>
   In contrast to <command>CREATE TABLE AS</command>, <command>SELECT
   INTO</command> does not allow specifying properties like a table's access
   method with <xref linkend="sql-createtable-method" /> or the table's
   tablespace with <xref linkend="sql-createtable-tablespace" />. Use
   <command>CREATE TABLE AS</command> if necessary.  Therefore, the default table
   access method is chosen for the new table. See <xref
   linkend="guc-default-table-access-method"/> for more information.
  </para>
 </refsect1>

 <refsect1>
  <title>Examples</title>

  <para>
   Create a new table <literal>films_recent</literal> consisting of only
   recent entries from the table <literal>films</literal>:

<programlisting>
SELECT * INTO films_recent FROM films WHERE date_prod &gt;= '2002-01-01';
</programlisting></para>
 </refsect1>

 <refsect1>
  <title>Compatibility</title>

  <para>
   The SQL standard uses <command>SELECT INTO</command> to
   represent selecting values into scalar variables of a host program,
   rather than creating a new table.  This indeed is the usage found
   in <application>ECPG</application> (see <xref linkend="ecpg"/>) and
   <application>PL/pgSQL</application> (see <xref linkend="plpgsql"/>).
   The <productname>PostgreSQL</productname> usage of <command>SELECT
   INTO</command> to represent table creation is historical.  Some other SQL
   implementations also use <command>SELECT INTO</command> in this way (but
   most SQL implementations support <command>CREATE TABLE AS</command>
   instead).  Apart from such compatibility considerations, it is best to use
   <command>CREATE TABLE AS</command> for this purpose in new code.
  </para>
 </refsect1>

 <refsect1>
  <title>See Also</title>

  <simplelist type="inline">
   <member><xref linkend="sql-createtableas"/></member>
  </simplelist>
 </refsect1>
</refentry>