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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>dblink_open</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="contrib-dblink-exec.html" title="dblink_exec" /><link rel="next" href="contrib-dblink-fetch.html" title="dblink_fetch" /></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">dblink_open</th></tr><tr><td width="10%" align="left"><a accesskey="p" href="contrib-dblink-exec.html" title="dblink_exec">Prev</a> </td><td width="10%" align="left"><a accesskey="u" href="dblink.html" title="F.10. dblink">Up</a></td><th width="60%" align="center">F.10. dblink</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="contrib-dblink-fetch.html" title="dblink_fetch">Next</a></td></tr></table><hr></hr></div><div class="refentry" id="CONTRIB-DBLINK-OPEN"><div class="titlepage"></div><a id="id-1.11.7.19.10.1" class="indexterm"></a><div class="refnamediv"><h2><span class="refentrytitle">dblink_open</span></h2><p>dblink_open — opens a cursor in a remote database</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><pre class="synopsis">
- dblink_open(text cursorname, text sql [, bool fail_on_error]) returns text
- dblink_open(text connname, text cursorname, text sql [, bool fail_on_error]) returns text
- </pre></div><div class="refsect1" id="id-1.11.7.19.10.5"><h2>Description</h2><p>
- <code class="function">dblink_open()</code> opens a cursor in a remote database.
- The cursor can subsequently be manipulated with
- <code class="function">dblink_fetch()</code> and <code class="function">dblink_close()</code>.
- </p></div><div class="refsect1" id="id-1.11.7.19.10.6"><h2>Arguments</h2><div class="variablelist"><dl class="variablelist"><dt><span class="term"><em class="parameter"><code>connname</code></em></span></dt><dd><p>
- Name of the connection to use; omit this parameter to use the
- unnamed connection.
- </p></dd><dt><span class="term"><em class="parameter"><code>cursorname</code></em></span></dt><dd><p>
- The name to assign to this cursor.
- </p></dd><dt><span class="term"><em class="parameter"><code>sql</code></em></span></dt><dd><p>
- The <code class="command">SELECT</code> statement that you wish to execute in the remote
- database, for example <code class="literal">select * from pg_class</code>.
- </p></dd><dt><span class="term"><em class="parameter"><code>fail_on_error</code></em></span></dt><dd><p>
- If true (the default when omitted) then an error thrown on the
- remote side of the connection causes an error to also be thrown
- locally. If false, the remote error is locally reported as a NOTICE,
- and the function's return value is set to <code class="literal">ERROR</code>.
- </p></dd></dl></div></div><div class="refsect1" id="id-1.11.7.19.10.7"><h2>Return Value</h2><p>
- Returns status, either <code class="literal">OK</code> or <code class="literal">ERROR</code>.
- </p></div><div class="refsect1" id="id-1.11.7.19.10.8"><h2>Notes</h2><p>
- Since a cursor can only persist within a transaction,
- <code class="function">dblink_open</code> starts an explicit transaction block
- (<code class="command">BEGIN</code>) on the remote side, if the remote side was
- not already within a transaction. This transaction will be
- closed again when the matching <code class="function">dblink_close</code> is
- executed. Note that if
- you use <code class="function">dblink_exec</code> to change data between
- <code class="function">dblink_open</code> and <code class="function">dblink_close</code>,
- and then an error occurs or you use <code class="function">dblink_disconnect</code> before
- <code class="function">dblink_close</code>, your change <span class="emphasis"><em>will be
- lost</em></span> because the transaction will be aborted.
- </p></div><div class="refsect1" id="id-1.11.7.19.10.9"><h2>Examples</h2><pre class="screen">
- SELECT dblink_connect('dbname=postgres options=-csearch_path=');
- dblink_connect
- ----------------
- OK
- (1 row)
-
- SELECT dblink_open('foo', 'select proname, prosrc from pg_proc');
- dblink_open
- -------------
- OK
- (1 row)
- </pre></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="contrib-dblink-exec.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="dblink.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="contrib-dblink-fetch.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">dblink_exec </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> dblink_fetch</td></tr></table></div></body></html>
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