doc/src/sgml/ref/drop_routine.sgml - master - githubmirror/postgres

doc/src/sgml/ref/drop_routine.sgml
123 строки4 KB
Tom Lane
Reconsider the handling of procedure OUT parameters.
11 июн 2021, 00:11
11 июн 2021, 00:11e56bce5
<!--
doc/src/sgml/ref/drop_routine.sgml
PostgreSQL documentation
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<refentry id="sql-droproutine">
 <indexterm zone="sql-droproutine">
  <primary>DROP ROUTINE</primary>
 </indexterm>

 <refmeta>
  <refentrytitle>DROP ROUTINE</refentrytitle>
  <manvolnum>7</manvolnum>
  <refmiscinfo>SQL - Language Statements</refmiscinfo>
 </refmeta>

 <refnamediv>
  <refname>DROP ROUTINE</refname>
  <refpurpose>remove a routine</refpurpose>
 </refnamediv>

 <refsynopsisdiv>
<synopsis>
DROP ROUTINE [ IF EXISTS ] <replaceable class="parameter">name</replaceable> [ ( [ [ <replaceable class="parameter">argmode</replaceable> ] [ <replaceable class="parameter">argname</replaceable> ] <replaceable class="parameter">argtype</replaceable> [, ...] ] ) ] [, ...]
    [ CASCADE | RESTRICT ]
</synopsis>
 </refsynopsisdiv>

 <refsect1>
  <title>Description</title>

  <para>
   <command>DROP ROUTINE</command> removes the definition of one or more
   existing routines.  The term <quote>routine</quote> includes
   aggregate functions, normal functions, and procedures.  See
   under <xref linkend="sql-dropaggregate"/>, <xref linkend="sql-dropfunction"/>,
   and <xref linkend="sql-dropprocedure"/> for the description of the
   parameters, more examples, and further details.
  </para>
 </refsect1>

 <refsect1 id="sql-droproutine-notes">
  <title>Notes</title>

  <para>
   The lookup rules used by <command>DROP ROUTINE</command> are
   fundamentally the same as for <command>DROP PROCEDURE</command>; in
   particular, <command>DROP ROUTINE</command> shares that command's
   behavior of considering an argument list that has
   no <replaceable class="parameter">argmode</replaceable> markers to be
   possibly using the SQL standard's definition that <literal>OUT</literal>
   arguments are included in the list.  (<command>DROP AGGREGATE</command>
   and <command>DROP FUNCTION</command> do not do that.)
  </para>

  <para>
   In some cases where the same name is shared by routines of different
   kinds, it is possible for <command>DROP ROUTINE</command> to fail with
   an ambiguity error when a more specific command (<command>DROP
   FUNCTION</command>, etc.) would work.  Specifying the argument type
   list more carefully will also resolve such problems.
  </para>

  <para>
   These lookup rules are also used by other commands that
   act on existing routines, such as <command>ALTER ROUTINE</command>
   and <command>COMMENT ON ROUTINE</command>.
  </para>
 </refsect1>

 <refsect1 id="sql-droproutine-examples">
  <title>Examples</title>

  <para>
   To drop the routine <literal>foo</literal> for type
   <type>integer</type>:
<programlisting>
DROP ROUTINE foo(integer);
</programlisting>
   This command will work independent of whether <literal>foo</literal> is an
   aggregate, function, or procedure.
  </para>
 </refsect1>

 <refsect1 id="sql-droproutine-compatibility">
  <title>Compatibility</title>

  <para>
   This command conforms to the SQL standard, with
   these <productname>PostgreSQL</productname> extensions:
   <itemizedlist>
    <listitem>
     <para>The standard only allows one routine to be dropped per command.</para>
    </listitem>
    <listitem>
     <para>The <literal>IF EXISTS</literal> option is an extension.</para>
    </listitem>
    <listitem>
     <para>The ability to specify argument modes and names is an
     extension, and the lookup rules differ when modes are given.</para>
    </listitem>
    <listitem>
     <para>User-definable aggregate functions are an extension.</para>
    </listitem>
   </itemizedlist></para>
 </refsect1>

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

  <simplelist type="inline">
   <member><xref linkend="sql-dropaggregate"/></member>
   <member><xref linkend="sql-dropfunction"/></member>
   <member><xref linkend="sql-dropprocedure"/></member>
   <member><xref linkend="sql-alterroutine"/></member>
  </simplelist>

  <para>
   Note that there is no <literal>CREATE ROUTINE</literal> command.
  </para>
 </refsect1>

</refentry>