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<!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><div xmlns="http://www.w3.org/TR/xhtml1/transitional" 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 11.5 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></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">
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> [, ...] ] ) ] [, ...]
[ CASCADE | RESTRICT ]
</pre></div><div class="refsect1" id="id-1.9.3.114.5"><h2>Description</h2><p>
<code class="command">DROP FUNCTION</code> removes the definition of an existing
function. To execute this command the user must be the
owner of the function. The argument types to the
function must be specified, since several different functions
can exist with the same name and different argument lists.
</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>
Do not throw an error if the function does not exist. A notice is issued
in this case.
</p></dd><dt><span class="term"><em class="replaceable"><code>name</code></em></span></dt><dd><p>
The name (optionally schema-qualified) of an existing function. If no
argument list is specified, the name must be unique in its schema.
</p></dd><dt><span class="term"><em class="replaceable"><code>argmode</code></em></span></dt><dd><p>
The mode of an argument: <code class="literal">IN</code>, <code class="literal">OUT</code>,
<code class="literal">INOUT</code>, or <code class="literal">VARIADIC</code>.
If omitted, the default is <code class="literal">IN</code>.
Note that <code class="command">DROP FUNCTION</code> does not actually pay
any attention to <code class="literal">OUT</code> arguments, since only the input
arguments are needed to determine the function's identity.
So it is sufficient to list the <code class="literal">IN</code>, <code class="literal">INOUT</code>,
and <code class="literal">VARIADIC</code> arguments.
</p></dd><dt><span class="term"><em class="replaceable"><code>argname</code></em></span></dt><dd><p>
The name of an argument.
Note that <code class="command">DROP FUNCTION</code> does not actually pay
any attention to argument names, since only the argument data
types are needed to determine the function's identity.
</p></dd><dt><span class="term"><em class="replaceable"><code>argtype</code></em></span></dt><dd><p>
The data type(s) of the function's arguments (optionally
schema-qualified), if any.
</p></dd><dt><span class="term"><code class="literal">CASCADE</code></span></dt><dd><p>
Automatically drop objects that depend on the function (such as
operators or triggers),
and in turn all objects that depend on those objects
(see <a class="xref" href="ddl-depend.html" title="5.13. Dependency Tracking">Section 5.13</a>).
</p></dd><dt><span class="term"><code class="literal">RESTRICT</code></span></dt><dd><p>
Refuse to drop the function if any objects depend on it. This
is the default.
</p></dd></dl></div></div><div class="refsect1" id="SQL-DROPFUNCTION-EXAMPLES"><h2>Examples</h2><p>
This command removes the square root function:
</p><pre class="programlisting">
DROP FUNCTION sqrt(integer);
</pre><p>
Drop multiple functions in one command:
</p><pre class="programlisting">
DROP FUNCTION sqrt(integer), sqrt(bigint);
</pre><p>
If the function name is unique in its schema, it can be referred to without
an argument list:
</p><pre class="programlisting">
DROP FUNCTION update_employee_salaries;
</pre><p>
Note that this is different from
</p><pre class="programlisting">
DROP FUNCTION update_employee_salaries();
</pre><p>
which refers to a function with zero arguments, whereas the first variant
can refer to a function with any number of arguments, including zero, as
long as the name is unique.
</p></div><div class="refsect1" id="SQL-DROPFUNCTION-COMPATIBILITY"><h2>Compatibility</h2><p>
This command conforms to the SQL standard, with
these <span class="productname">PostgreSQL</span> extensions:
</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><p>
</p></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">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="sql-commands.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="sql-dropgroup.html">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">Home</a></td><td width="40%" align="right" valign="top"> DROP GROUP</td></tr></table></div></body></html>
