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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>UNLISTEN</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-truncate.html" title="TRUNCATE" /><link rel="next" href="sql-update.html" title="UPDATE" /></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">UNLISTEN</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="sql-truncate.html" title="TRUNCATE">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-update.html" title="UPDATE">Next</a></td></tr></table><hr></hr></div><div class="refentry" id="SQL-UNLISTEN"><div class="titlepage"></div><a id="id-1.9.3.181.1" class="indexterm"></a><div class="refnamediv"><h2><span class="refentrytitle">UNLISTEN</span></h2><p>UNLISTEN — stop listening for a notification</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><pre class="synopsis">
UNLISTEN { <em class="replaceable"><code>channel</code></em> | * }
</pre></div><div class="refsect1" id="id-1.9.3.181.5"><h2>Description</h2><p>
<code class="command">UNLISTEN</code> is used to remove an existing
registration for <code class="command">NOTIFY</code> events.
<code class="command">UNLISTEN</code> cancels any existing registration of
the current <span class="productname">PostgreSQL</span> session as a
listener on the notification channel named <em class="replaceable"><code>channel</code></em>. The special wildcard
<code class="literal">*</code> cancels all listener registrations for the
current session.
</p><p>
<a class="xref" href="sql-notify.html" title="NOTIFY"><span class="refentrytitle">NOTIFY</span></a>
contains a more extensive
discussion of the use of <code class="command">LISTEN</code> and
<code class="command">NOTIFY</code>.
</p></div><div class="refsect1" id="id-1.9.3.181.6"><h2>Parameters</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="replaceable"><code>channel</code></em></span></dt><dd><p>
Name of a notification channel (any identifier).
</p></dd><dt><span class="term"><code class="literal">*</code></span></dt><dd><p>
All current listen registrations for this session are cleared.
</p></dd></dl></div></div><div class="refsect1" id="id-1.9.3.181.7"><h2>Notes</h2><p>
You can unlisten something you were not listening for; no warning or error
will appear.
</p><p>
At the end of each session, <code class="command">UNLISTEN *</code> is
automatically executed.
</p><p>
A transaction that has executed <code class="command">UNLISTEN</code> cannot be
prepared for two-phase commit.
</p></div><div class="refsect1" id="id-1.9.3.181.8"><h2>Examples</h2><p>
To make a registration:
</p><pre class="programlisting">
LISTEN virtual;
NOTIFY virtual;
Asynchronous notification "virtual" received from server process with PID 8448.
</pre><p>
</p><p>
Once <code class="command">UNLISTEN</code> has been executed, further <code class="command">NOTIFY</code>
messages will be ignored:
</p><pre class="programlisting">
UNLISTEN virtual;
NOTIFY virtual;
-- no NOTIFY event is received
</pre></div><div class="refsect1" id="id-1.9.3.181.9"><h2>Compatibility</h2><p>
There is no <code class="command">UNLISTEN</code> command in the SQL standard.
</p></div><div class="refsect1" id="id-1.9.3.181.10"><h2>See Also</h2><span class="simplelist"><a class="xref" href="sql-listen.html" title="LISTEN"><span class="refentrytitle">LISTEN</span></a>, <a class="xref" href="sql-notify.html" title="NOTIFY"><span class="refentrytitle">NOTIFY</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-truncate.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-update.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">TRUNCATE </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> UPDATE</td></tr></table></div></body></html>
