doc/src/sgml/ref/insert.sgml

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$PostgreSQL: pgsql/doc/src/sgml/ref/insert.sgml,v 1.34 2006/10/23 18:10:32 petere Exp $
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<refentry id="SQL-INSERT">
 <refmeta>
  <refentrytitle id="SQL-INSERT-TITLE">INSERT</refentrytitle>
  <refmiscinfo>SQL - Language Statements</refmiscinfo>
 </refmeta>

 <refnamediv>
  <refname>INSERT</refname>
  <refpurpose>create new rows in a table</refpurpose>
 </refnamediv>

 <indexterm zone="sql-insert">
  <primary>INSERT</primary>
 </indexterm>

 <refsynopsisdiv>
<synopsis>
INSERT INTO <replaceable class="PARAMETER">table</replaceable> [ ( <replaceable class="PARAMETER">column</replaceable> [, ...] ) ]
    { DEFAULT VALUES | VALUES ( { <replaceable class="PARAMETER">expression</replaceable> | DEFAULT } [, ...] ) [, ...] | <replaceable class="PARAMETER">query</replaceable> }
    [ RETURNING * | <replaceable class="parameter">output_expression</replaceable> [ AS <replaceable class="parameter">output_name</replaceable> ] [, ...] ]
</synopsis>
 </refsynopsisdiv>

 <refsect1>
  <title>Description</title>

  <para>
   <command>INSERT</command> inserts new rows into a table.
   One can insert one or more rows specified by value expressions,
   or zero or more rows resulting from a query.
  </para>

  <para>
   The target column names may be listed in any order.  If no list of
   column names is given at all, the default is all the columns of the
   table in their declared order; or the first <replaceable>N</> column
   names, if there are only <replaceable>N</> columns supplied by the
   <literal>VALUES</> clause or <replaceable>query</>.  The values
   supplied by the <literal>VALUES</> clause or <replaceable>query</> are
   associated with the explicit or implicit column list left-to-right.
  </para>

  <para>
   Each column not present in the explicit or implicit column list will be
   filled with a default value, either its declared default value
   or null if there is none.
  </para>

  <para>
   If the expression for any column is not of the correct data type,
   automatic type conversion will be attempted.
  </para>

  <para>
   The optional <literal>RETURNING</> clause causes <command>INSERT</>
   to compute and return value(s) based on each row actually inserted.
   This is primarily useful for obtaining values that were supplied by
   defaults, such as a serial sequence number.  However, any expression
   using the table's columns is allowed.  The syntax of the
   <literal>RETURNING</> list is identical to that of the output list
   of <command>SELECT</>.
  </para>

  <para>
   You must have <literal>INSERT</literal> privilege on a table in
   order to insert into it, and <literal>SELECT</> privilege on it to
   use <literal>RETURNING</>.  If you use the <replaceable
   class="PARAMETER">query</replaceable> clause to insert rows from a
   query, you also need to have <literal>SELECT</literal> privilege on
   any table used in the query.
  </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">column</replaceable></term>
    <listitem>
     <para>
      The name of a column in <replaceable class="PARAMETER">table</replaceable>.
      The column name can be qualified with a subfield name or array
      subscript, if needed.  (Inserting into only some fields of a
      composite column leaves the other fields null.)
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><literal>DEFAULT VALUES</literal></term>
    <listitem>
     <para>
      All columns will be filled with their default values.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><replaceable class="PARAMETER">expression</replaceable></term>
    <listitem>
     <para>
      An expression or value to assign to the corresponding <replaceable
      class="PARAMETER">column</replaceable>.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><literal>DEFAULT</literal></term>
    <listitem>
     <para>
      The corresponding <replaceable>column</replaceable> will be filled with
      its default value.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><replaceable class="PARAMETER">query</replaceable></term>
    <listitem>
     <para>
      A query (<command>SELECT</command> statement) that supplies the
      rows to be inserted.  Refer to the
      <xref linkend="sql-select" endterm="sql-select-title">
      statement for a description of the syntax.
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><replaceable class="PARAMETER">output_expression</replaceable></term>
    <listitem>
     <para>
      An expression to be computed and returned by the <command>INSERT</>
      command after each row is inserted.  The expression may use any
      column names of the <replaceable class="PARAMETER">table</replaceable>.
      Write <literal>*</> to return all columns of the inserted row(s).
     </para>
    </listitem>
   </varlistentry>

   <varlistentry>
    <term><replaceable class="PARAMETER">output_name</replaceable></term>
    <listitem>
     <para>
      A name to use for a returned column.
     </para>
    </listitem>
   </varlistentry>
  </variablelist>
 </refsect1>

 <refsect1>
  <title>Outputs</title>

  <para>
   On successful completion, an <command>INSERT</> command returns a command
   tag of the form
<screen>
INSERT <replaceable>oid</replaceable> <replaceable class="parameter">count</replaceable>
</screen>
   The <replaceable class="parameter">count</replaceable> is the number
   of rows inserted.  If <replaceable class="parameter">count</replaceable>
   is exactly one, and the target table has OIDs, then
   <replaceable class="parameter">oid</replaceable> is the
   <acronym>OID</acronym> assigned to the inserted row.  Otherwise
   <replaceable class="parameter">oid</replaceable> is zero.
  </para>

  <para>
   If the <command>INSERT</> command contains a <literal>RETURNING</>
   clause, the result will be similar to that of a <command>SELECT</>
   statement containing the columns and values defined in the
   <literal>RETURNING</> list, computed over the row(s) inserted by the
   command.
  </para>
 </refsect1>

 <refsect1>
  <title>Examples</title>

  <para>
   Insert a single row into table <literal>films</literal>:

<programlisting>
INSERT INTO films VALUES
    ('UA502', 'Bananas', 105, '1971-07-13', 'Comedy', '82 minutes');
</programlisting>
  </para>

  <para>
   In this example, the <literal>len</literal> column is
   omitted and therefore it will have the default value:

<programlisting>
INSERT INTO films (code, title, did, date_prod, kind)
    VALUES ('T_601', 'Yojimbo', 106, '1961-06-16', 'Drama');
</programlisting>
  </para>

  <para>
   This example uses the <literal>DEFAULT</literal> clause for
   the date columns rather than specifying a value:

<programlisting>
INSERT INTO films VALUES
    ('UA502', 'Bananas', 105, DEFAULT, 'Comedy', '82 minutes');
INSERT INTO films (code, title, did, date_prod, kind)
    VALUES ('T_601', 'Yojimbo', 106, DEFAULT, 'Drama');
</programlisting>
  </para>

  <para>
   To insert a row consisting entirely of default values:

<programlisting>
INSERT INTO films DEFAULT VALUES;
</programlisting>
  </para>

  <para>
   To insert multiple rows using the multirow <command>VALUES</> syntax:

<programlisting>
INSERT INTO films (code, title, did, date_prod, kind) VALUES
    ('B6717', 'Tampopo', 110, '1985-02-10', 'Comedy'),
    ('HG120', 'The Dinner Game', 140, DEFAULT, 'Comedy');
</programlisting>
  </para>

  <para>
   This example inserts some rows into table
   <literal>films</literal> from a table <literal>tmp_films</literal>
   with the same column layout as <literal>films</literal>:

<programlisting>
INSERT INTO films SELECT * FROM tmp_films WHERE date_prod &lt; '2004-05-07';
</programlisting>
  </para>

  <para>
   This example inserts into array columns:

<programlisting>
-- Create an empty 3x3 gameboard for noughts-and-crosses
INSERT INTO tictactoe (game, board[1:3][1:3])
    VALUES (1, '{{" "," "," "},{" "," "," "},{" "," "," "}}');
-- The subscripts in the above example aren't really needed
INSERT INTO tictactoe (game, board)
    VALUES (2, '{{X," "," "},{" ",O," "},{" ",X," "}}');
</programlisting>
  </para>

  <para>
   Insert a single row into table <literal>distributors</literal>, returning
   the sequence number generated by the <literal>DEFAULT</literal> clause:

<programlisting>
INSERT INTO distributors (did, dname) VALUES (DEFAULT, 'XYZ Widgets')
   RETURNING did;
</programlisting>
  </para>
 </refsect1>

 <refsect1>
  <title>Compatibility</title>

  <para>
   <command>INSERT</command> conforms to the SQL standard, except that
   the <literal>RETURNING</> clause is a
   <productname>PostgreSQL</productname> extension.  Also, the case in
   which a column name list is omitted, but not all the columns are
   filled from the <literal>VALUES</> clause or <replaceable>query</>,
   is disallowed by the standard.
  </para>

  <para>
   Possible limitations of the <replaceable
   class="PARAMETER">query</replaceable> clause are documented under
   <xref linkend="sql-select" endterm="sql-select-title">.
  </para>
 </refsect1>
</refentry>