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   2 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>DROP FUNCTION</title><link rel="stylesheet" type="text/css" href="stylesheet.css" /><link rev="made" href="pgsql-docs@lists.postgresql.org" /><meta name="generator" content="DocBook XSL Stylesheets Vsnapshot" /><link rel="prev" href="sql-dropforeigntable.html" title="DROP FOREIGN TABLE" /><link rel="next" href="sql-dropgroup.html" title="DROP GROUP" /></head><body id="docContent" class="container-fluid col-10"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="5" align="center">DROP FUNCTION</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="sql-dropforeigntable.html" title="DROP FOREIGN TABLE">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="sql-commands.html" title="SQL Commands">Up</a></td><th width="60%" align="center">SQL Commands</th><td width="10%" align="right"><a accesskey="h" href="index.html" title="PostgreSQL 18.0 Documentation">Home</a></td><td width="10%" align="right"> <a accesskey="n" href="sql-dropgroup.html" title="DROP GROUP">Next</a></td></tr></table><hr /></div><div class="refentry" id="SQL-DROPFUNCTION"><div class="titlepage"></div><a id="id-1.9.3.114.1" class="indexterm"></a><div class="refnamediv"><h2><span class="refentrytitle">DROP FUNCTION</span></h2><p>DROP FUNCTION — remove a function</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><pre class="synopsis">
   3 DROP FUNCTION [ IF EXISTS ] <em class="replaceable"><code>name</code></em> [ ( [ [ <em class="replaceable"><code>argmode</code></em> ] [ <em class="replaceable"><code>argname</code></em> ] <em class="replaceable"><code>argtype</code></em> [, ...] ] ) ] [, ...]
   4     [ CASCADE | RESTRICT ]
   5 </pre></div><div class="refsect1" id="id-1.9.3.114.5"><h2>Description</h2><p>
   6    <code class="command">DROP FUNCTION</code> removes the definition of an existing
   7    function. To execute this command the user must be the
   8    owner of the function. The argument types to the
   9    function must be specified, since several different functions
  10    can exist with the same name and different argument lists.
  11   </p></div><div class="refsect1" id="id-1.9.3.114.6"><h2>Parameters</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><code class="literal">IF EXISTS</code></span></dt><dd><p>
  12       Do not throw an error if the function does not exist. A notice is issued
  13       in this case.
  14      </p></dd><dt><span class="term"><em class="replaceable"><code>name</code></em></span></dt><dd><p>
  15       The name (optionally schema-qualified) of an existing function.  If no
  16       argument list is specified, the name must be unique in its schema.
  17      </p></dd><dt><span class="term"><em class="replaceable"><code>argmode</code></em></span></dt><dd><p>
  18       The mode of an argument: <code class="literal">IN</code>, <code class="literal">OUT</code>,
  19       <code class="literal">INOUT</code>, or <code class="literal">VARIADIC</code>.
  20       If omitted, the default is <code class="literal">IN</code>.
  21       Note that <code class="command">DROP FUNCTION</code> does not actually pay
  22       any attention to <code class="literal">OUT</code> arguments, since only the input
  23       arguments are needed to determine the function's identity.
  24       So it is sufficient to list the <code class="literal">IN</code>, <code class="literal">INOUT</code>,
  25       and <code class="literal">VARIADIC</code> arguments.
  26      </p></dd><dt><span class="term"><em class="replaceable"><code>argname</code></em></span></dt><dd><p>
  27       The name of an argument.
  28       Note that <code class="command">DROP FUNCTION</code> does not actually pay
  29       any attention to argument names, since only the argument data
  30       types are needed to determine the function's identity.
  31      </p></dd><dt><span class="term"><em class="replaceable"><code>argtype</code></em></span></dt><dd><p>
  32       The data type(s) of the function's arguments (optionally
  33       schema-qualified), if any.
  34      </p></dd><dt><span class="term"><code class="literal">CASCADE</code></span></dt><dd><p>
  35       Automatically drop objects that depend on the function (such as
  36       operators or triggers),
  37       and in turn all objects that depend on those objects
  38       (see <a class="xref" href="ddl-depend.html" title="5.15. Dependency Tracking">Section 5.15</a>).
  39      </p></dd><dt><span class="term"><code class="literal">RESTRICT</code></span></dt><dd><p>
  40       Refuse to drop the function if any objects depend on it.  This
  41       is the default.
  42      </p></dd></dl></div></div><div class="refsect1" id="SQL-DROPFUNCTION-EXAMPLES"><h2>Examples</h2><p>
  43    This command removes the square root function:
  44
  45 </p><pre class="programlisting">
  46 DROP FUNCTION sqrt(integer);
  47 </pre><p>
  48    Drop multiple functions in one command:
  49 </p><pre class="programlisting">
  50 DROP FUNCTION sqrt(integer), sqrt(bigint);
  51 </pre><p>
  52    If the function name is unique in its schema, it can be referred to without
  53    an argument list:
  54 </p><pre class="programlisting">
  55 DROP FUNCTION update_employee_salaries;
  56 </pre><p>
  57    Note that this is different from
  58 </p><pre class="programlisting">
  59 DROP FUNCTION update_employee_salaries();
  60 </pre><p>
  61    which refers to a function with zero arguments, whereas the first variant
  62    can refer to a function with any number of arguments, including zero, as
  63    long as the name is unique.
  64   </p></div><div class="refsect1" id="SQL-DROPFUNCTION-COMPATIBILITY"><h2>Compatibility</h2><p>
  65    This command conforms to the SQL standard, with
  66    these <span class="productname">PostgreSQL</span> extensions:
  67    </p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><p>The standard only allows one function to be dropped per command.</p></li><li class="listitem"><p>The <code class="literal">IF EXISTS</code> option</p></li><li class="listitem"><p>The ability to specify argument modes and names</p></li></ul></div></div><div class="refsect1" id="id-1.9.3.114.9"><h2>See Also</h2><span class="simplelist"><a class="xref" href="sql-createfunction.html" title="CREATE FUNCTION"><span class="refentrytitle">CREATE FUNCTION</span></a>, <a class="xref" href="sql-alterfunction.html" title="ALTER FUNCTION"><span class="refentrytitle">ALTER FUNCTION</span></a>, <a class="xref" href="sql-dropprocedure.html" title="DROP PROCEDURE"><span class="refentrytitle">DROP PROCEDURE</span></a>, <a class="xref" href="sql-droproutine.html" title="DROP ROUTINE"><span class="refentrytitle">DROP ROUTINE</span></a></span></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="sql-dropforeigntable.html" title="DROP FOREIGN TABLE">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="sql-commands.html" title="SQL Commands">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="sql-dropgroup.html" title="DROP GROUP">Next</a></td></tr><tr><td width="40%" align="left" valign="top">DROP FOREIGN TABLE </td><td width="20%" align="center"><a accesskey="h" href="index.html" title="PostgreSQL 18.0 Documentation">Home</a></td><td width="40%" align="right" valign="top"> DROP GROUP</td></tr></table></div></body></html>