pg-trace.xml

<?xml version="1.0" encoding="utf-8"?>
<!-- $Revision$ -->
<!-- EN-Revision: 3f2e2d4a8c98368d8cd5dcf73d4728dfb4517f6d Maintainer: dallas Status: ready -->
<!-- CREDITS: mowangjuanzi -->
<!-- splitted from ./en/functions/pgsql.xml, last change in rev 1.7 -->
<refentry xml:id="function.pg-trace" xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink">
 <refnamediv>
  <refname>pg_trace</refname>
  <refpurpose>启用 PostgreSQL 连接的追踪</refpurpose>
 </refnamediv>

 <refsect1 role="description">
  &reftitle.description;
  <methodsynopsis>
   <type>bool</type><methodname>pg_trace</methodname>
   <methodparam><type>string</type><parameter>filename</parameter></methodparam>
   <methodparam choice="opt"><type>string</type><parameter>mode</parameter><initializer>"w"</initializer></methodparam>
   <methodparam choice="opt"><type class="union"><type>PgSql\Connection</type><type>null</type></type><parameter>connection</parameter><initializer>&null;</initializer></methodparam>
   <methodparam choice="opt"><type>int</type><parameter>trace_mode</parameter><initializer>0</initializer></methodparam>
  </methodsynopsis>
  <para>
   <function>pg_trace</function> 启用 PostgreSQL 前后端通讯的追踪并记录到文件。要完全理解结果，需要熟悉 PostgreSQL 通讯协议的内部工作原理。
  </para>
  <para>
   对不熟悉的人来说，追踪发送到服务器的查询错误依然有用，例如可以用 <command>grep '^To backend' trace.log</command> 来查看实际发送到 PostgreSQL
   服务器的查询。更多信息参考 <link xlink:href="&url.pgsql.manual;">PostgreSQL 手册</link>。
  </para>
 </refsect1>

 <refsect1 role="parameters">
  &reftitle.parameters;
  <para>
   <variablelist>
    <varlistentry>
     <term><parameter>filename</parameter></term>
     <listitem>
      <para>
       写入追踪日志的文件完整路径和文件名，与 <function>fopen</function> 一致。
      </para>
     </listitem>
    </varlistentry>
    <varlistentry>
     <term><parameter>mode</parameter></term>
     <listitem>
      <para>
       可选的文件访问模式，同 <function>fopen</function>。
      </para>
     </listitem>
    </varlistentry>
    <varlistentry>
     <term><parameter>connection</parameter></term>
     <listitem>
      &pgsql.parameter.connection-with-nullable-default;
     </listitem>
    </varlistentry>
    <varlistentry>
     <term><parameter>trace_mode</parameter></term>
     <listitem>
      <para>
       可选的 trace 模式，使用下列常量 <constant>PGSQL_TRACE_SUPPRESS_TIMESTAMPS</constant> 和
       <constant>PGSQL_TRACE_REGRESS_MODE</constant>
      </para>
     </listitem>
    </varlistentry>
   </variablelist>
  </para>
 </refsect1>

 <refsect1 role="returnvalues">
  &reftitle.returnvalues;
  <para>
   &return.success;
  </para>
 </refsect1>

 <refsect1 role="changelog">
  &reftitle.changelog;
  <informaltable>
   <tgroup cols="2">
    <thead>
     <row>
      <entry>&Version;</entry>
      <entry>&Description;</entry>
     </row>
    </thead>
    <tbody>
     <row>
      <entry>8.3.0</entry>
      <entry>
       新增 <parameter>trace_mode</parameter>。
      </entry>
     </row>
     &pgsql.changelog.connection-object;
     <row>
      <entry>8.0.0</entry>
      <entry>
       <parameter>connection</parameter> 现在可为 null。
      </entry>
     </row>
    </tbody>
   </tgroup>
  </informaltable>
 </refsect1>
 
 <refsect1 role="examples">
  &reftitle.examples;
  <para>
   <example>
    <title><function>pg_trace</function> 示例</title>
    <programlisting role="php">
<![CDATA[
<?php
$pgsql_conn = pg_connect("dbname=mark host=localhost");

if ($pgsql_conn) {
   pg_trace('/tmp/trace.log', 'w', $pgsql_conn);
   pg_query("SELECT 1");
   pg_untrace($pgsql_conn);
   // Now /tmp/trace.log will contain backend communication
} else {
   print pg_last_error($pgsql_conn);
   exit;
}
?>
]]>
    </programlisting>
   </example>
  </para>
 </refsect1>
 
 <refsect1 role="seealso">
  &reftitle.seealso;
  <para>
   <simplelist>
    <member><function>fopen</function></member>
    <member><function>pg_untrace</function></member>
   </simplelist>
  </para>
 </refsect1>
</refentry>
<!-- Keep this comment at the end of the file
Local variables:
mode: sgml
sgml-omittag:t
sgml-shorttag:t
sgml-minimize-attributes:nil
sgml-always-quote-attributes:t
sgml-indent-step:1
sgml-indent-data:t
indent-tabs-mode:nil
sgml-parent-document:nil
sgml-default-dtd-file:"~/.phpdoc/manual.ced"
sgml-exposed-tags:nil
sgml-local-catalogs:nil
sgml-local-ecat-files:nil
End:
vim600: syn=xml fen fdm=syntax fdl=2 si
vim: et tw=78 syn=sgml
vi: ts=1 sw=1
-->