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postgresql
7th chunk of `doc/src/sgml/dblink.sgml`
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</screen>
  </refsect1>
 </refentry>

 <refentry id="contrib-dblink-exec">
  <indexterm>
   <primary>dblink_exec</primary>
  </indexterm>

  <refmeta>
   <refentrytitle>dblink_exec</refentrytitle>
   <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
   <refname>dblink_exec</refname>
   <refpurpose>executes a command in a remote database</refpurpose>
  </refnamediv>

  <refsynopsisdiv>
<synopsis>
dblink_exec(text connname, text sql [, bool fail_on_error]) returns text
dblink_exec(text connstr, text sql [, bool fail_on_error]) returns text
dblink_exec(text sql [, bool fail_on_error]) returns text
</synopsis>
  </refsynopsisdiv>

  <refsect1>
   <title>Description</title>

   <para>
    <function>dblink_exec</function> executes a command (that is, any SQL statement
    that doesn't return rows) in a remote database.
   </para>

   <para>
    When two <type>text</type> arguments are given, the first one is first
    looked up as a persistent connection's name; if found, the command
    is executed on that connection.  If not found, the first argument
    is treated as a connection info string as for <function>dblink_connect</function>,
    and the indicated connection is made just for the duration of this command.
   </para>
  </refsect1>

  <refsect1>
   <title>Arguments</title>

   <variablelist>
    <varlistentry>
     <term><parameter>connname</parameter></term>
     <listitem>
      <para>
       Name of the connection to use; omit this parameter to use the
       unnamed connection.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry>
     <term><parameter>connstr</parameter></term>
     <listitem>
      <para>
       A connection info string, as previously described for
       <function>dblink_connect</function>.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry>
     <term><parameter>sql</parameter></term>
     <listitem>
      <para>
       The SQL command that you wish to execute in the remote database,
       for example
       <literal>insert into foo values(0, 'a', '{"a0","b0","c0"}')</literal>.
      </para>
     </listitem>
    </varlistentry>

    <varlistentry>
     <term><parameter>fail_on_error</parameter></term>
     <listitem>
      <para>
       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 <literal>ERROR</literal>.
      </para>
     </listitem>
    </varlistentry>
   </variablelist>
  </refsect1>

  <refsect1>
   <title>Return Value</title>

   <para>
    Returns status, either the command's status string or <literal>ERROR</literal>.
   </para>
  </refsect1>

  <refsect1>
   <title>Examples</title>

<screen>
SELECT dblink_connect('dbname=dblink_test_standby');
 dblink_connect
----------------
 OK
(1 row)

SELECT dblink_exec('insert into foo values(21, ''z'', ''{"a0","b0","c0"}'');');
   dblink_exec
-----------------
 INSERT 943366 1
(1 row)

SELECT dblink_connect('myconn', 'dbname=regression');
 dblink_connect
----------------
 OK
(1 row)

SELECT dblink_exec('myconn', 'insert into foo values(21, ''z'', ''{"a0","b0","c0"}'');');
   dblink_exec
------------------
 INSERT 6432584 1
(1 row)

SELECT dblink_exec('myconn', 'insert into pg_class values (''foo'')',false);
NOTICE:  sql error
DETAIL:  ERROR:  null value in column "relnamespace" violates not-null constraint

 dblink_exec
-------------
 ERROR
(1 row)
</screen>
  </refsect1>
 </refentry>

 <refentry id="contrib-dblink-open">
  <indexterm>
   <primary>dblink_open</primary>
  </indexterm>

  <refmeta>
   <refentrytitle>dblink_open</refentrytitle>
   <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
Title: dblink_exec: Executing Commands in a Remote Database
Summary
This section describes the `dblink_exec` function, which executes SQL commands that don't return rows in a remote database. It explains how the function can use a persistent connection name or a connection info string. The arguments, including `connname`, `connstr`, `sql`, and `fail_on_error`, are detailed. The function returns a status string or 'ERROR'. Examples are provided to illustrate inserting data into a remote database using both connection strings and named connections, as well as demonstrating the effect of the `fail_on_error` parameter. The section ends by transitioning to describing the `dblink_open` function.