<!-- doc/src/sgml/ref/drop_transform.sgml -->

<refentry id="SQL-DROPTRANSFORM">
 <indexterm zone="sql-droptransform">
  <primary>DROP TRANSFORM</primary>
 </indexterm>

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

 <refnamediv>
  <refname>DROP TRANSFORM</refname>
  <refpurpose>remove a transform</refpurpose>
 </refnamediv>

 <refsynopsisdiv>
<synopsis>
DROP TRANSFORM [ IF EXISTS ] FOR <replaceable>type_name</replaceable> LANGUAGE <replaceable>lang_name</replaceable> [ CASCADE | RESTRICT ]
</synopsis>
 </refsynopsisdiv>

 <refsect1 id="sql-droptransform-description">
  <title>Description</title>

  <para>
   <command>DROP TRANSFORM</command> removes a previously defined transform.
  </para>

  <para>
   To be able to drop a transform, you must own the type and the language.
   These are the same privileges that are required to create a transform.
  </para>
 </refsect1>

 <refsect1>
  <title>Parameters</title>

   <variablelist>

   <varlistentry>
    <term><literal>IF EXISTS</literal></term>
    <listitem>
     <para>
      Do not throw an error if the transform does not exist. A notice is issued
      in this case.
     </para>
    </listitem>
   </varlistentry>

    <varlistentry>
     <term><replaceable>type_name</replaceable></term>

     <listitem>
      <para>
       The name of the data type of the transform.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry>
     <term><replaceable>lang_name</replaceable></term>

     <listitem>
      <para>
       The name of the language of the transform.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry>
     <term><literal>CASCADE</literal></term>
     <listitem>
      <para>
       Automatically drop objects that depend on the transform,
       and in turn all objects that depend on those objects
       (see <xref linkend="ddl-depend">).
      </para>
     </listitem>
    </varlistentry>

    <varlistentry>
     <term><literal>RESTRICT</literal></term>
     <listitem>
      <para>
       Refuse to drop the transform if any objects depend on it.  This is the
       default.
      </para>
     </listitem>
    </varlistentry>
   </variablelist>
 </refsect1>

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

  <para>
   To drop the transform for type <type>hstore</type> and language
   <literal>plpythonu</literal>:
<programlisting>
DROP TRANSFORM FOR hstore LANGUAGE plpythonu;
</programlisting></para>
 </refsect1>

 <refsect1 id="sql-droptransform-compat">
  <title>Compatibility</title>

  <para>
   This form of <command>DROP TRANSFORM</command> is a
   <productname>PostgreSQL</productname> extension.  See <xref
   linkend="sql-createtransform"> for details.
  </para>
 </refsect1>

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

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

</refentry>