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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 V1.79.1" /><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 12.4 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="5.14. Dependency Tracking">Section 5.14</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>
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