postgresql/doc/src/sgml/ref/select_into.sgml
Tom Lane 986085a7f0 Improve the representation of FOR UPDATE/FOR SHARE so that we can
support both FOR UPDATE and FOR SHARE in one command, as well as both
NOWAIT and normal WAIT behavior.  The more general code is actually
simpler and cleaner.
2006-04-30 18:30:40 +00:00

161 lines
5.4 KiB
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$PostgreSQL: pgsql/doc/src/sgml/ref/select_into.sgml,v 1.37 2006/04/30 18:30:38 tgl Exp $
PostgreSQL documentation
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<refentry id="SQL-SELECTINTO">
<refmeta>
<refentrytitle id="SQL-SELECTINTO-TITLE">SELECT INTO</refentrytitle>
<refmiscinfo>SQL - Language Statements</refmiscinfo>
</refmeta>
<refnamediv>
<refname>SELECT INTO</refname>
<refpurpose>define a new table from the results of a query</refpurpose>
</refnamediv>
<indexterm zone="sql-selectinto">
<primary>SELECT INTO</primary>
</indexterm>
<refsynopsisdiv>
<synopsis>
SELECT [ ALL | DISTINCT [ ON ( <replaceable class="PARAMETER">expression</replaceable> [, ...] ) ] ]
* | <replaceable class="PARAMETER">expression</replaceable> [ AS <replaceable class="PARAMETER">output_name</replaceable> ] [, ...]
INTO [ TEMPORARY | TEMP ] [ 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> [, ...] ]
[ { UNION | INTERSECT | EXCEPT } [ ALL ] <replaceable class="PARAMETER">select</replaceable> ]
[ ORDER BY <replaceable class="PARAMETER">expression</replaceable> [ ASC | DESC | USING <replaceable class="PARAMETER">operator</replaceable> ] [, ...] ]
[ LIMIT { <replaceable class="PARAMETER">count</replaceable> | ALL } ]
[ OFFSET <replaceable class="PARAMETER">start</replaceable> ]
[ 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"
endterm="sql-createtable-title"> 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" endterm="sql-select-title">.
</para>
</refsect1>
<refsect1>
<title>Notes</title>
<para>
<xref linkend="sql-createtableas"
endterm="sql-createtableas-title"> 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>
Prior to <productname>PostgreSQL</> 8.1, the table created by
<command>SELECT INTO</command> included OIDs by default. In
<productname>PostgreSQL</productname> 8.1, this is not the case
&mdash; to include OIDs in the new table, the <xref
linkend="guc-default-with-oids"> configuration variable must be
enabled. Alternatively, <command>CREATE TABLE AS</command> can be
used with the <literal>WITH OIDS</literal> clause.
</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. 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" endterm="sql-createtableas-title"></member>
</simplelist>
</refsect1>
</refentry>
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