Merge pull request #331 from chegong18/master

update docguide.sgml，earthdistance.sgml，ecpg.sgml，errcodes.sgml and event-trigger.sgml

Author: ChenHuajun

postgresql/doc/src/sgml/docguide.sgml

@@ -139,7 +139,7 @@ ____________________________________________________________________________-->
      <listitem>
       <para>
        This is the definition of DocBook itself.  We currently use version
-       4.2; you cannot use later or earlier versions.  You need
+       4.5; you cannot use later or earlier versions.  You need
        the <acronym>XML</acronym> variant of the DocBook DTD, not
        the <acronym>SGML</acronym> variant.
       </para>
@@ -205,7 +205,7 @@ ____________________________________________________________________________-->
      <term><ulink url="https://www.oasis-open.org/docbook/">DocBook DTD</ulink></term>
      <listitem>
       <para>
-       这是 DocBook 本身的定义。我们目前使用版本 4.2；你不能使用更新或者更早的版本。你需要 DocBook DTD 的<acronym>XML</acronym>变体，而不是<acronym>SGML</acronym>变体。
+       这是 DocBook 本身的定义。我们目前使用版本 4.5；你不能使用更新或者更早的版本。你需要 DocBook DTD 的<acronym>XML</acronym>变体，而不是<acronym>SGML</acronym>变体。
       </para>
      </listitem>
     </varlistentry>
@@ -222,7 +222,7 @@ ____________________________________________________________________________-->
       </para>
      </listitem>
     </varlistentry>
-    
+
     <varlistentry>
      <term><command>xmllint</command>的<ulink url="http://xmlsoft.org/">Libxml2</ulink></term>
      <listitem>
@@ -383,7 +383,7 @@ ____________________________________________________________________________-->
    <para>
     If you use MacPorts, the following will get you set up:
 <programlisting>
-sudo port install docbook-xml-4.2 docbook-xsl fop
+sudo port install docbook-xml-4.5 docbook-xsl fop
 </programlisting>
     If you use Homebrew, use this:
 <programlisting>
@@ -394,7 +394,7 @@ ____________________________________________________________________________-->
    <para>
     如果使用MacPorts，下面的命令会帮你准备好一切：
 <programlisting>
-sudo port install docbook-xml-4.2 docbook-xsl fop
+sudo port install docbook-xml-4.5 docbook-xsl fop
 </programlisting>
     如果使用的是Homebrew，就用这个：
 <programlisting>
@@ -418,7 +418,7 @@ ____________________________________________________________________________-->
    like this:
 <screen>
 checking for xmllint... xmllint
-checking for DocBook XML V4.2... yes
+checking for DocBook XML V4.5... yes
 checking for dbtoepub... dbtoepub
 checking for xsltproc... xsltproc
 checking for fop... fop
@@ -431,7 +431,7 @@ ____________________________________________________________________________-->
    在你能编译文档之前，你需要运行<filename>configure</filename>脚本，就像你在编译<productname>PostgreSQL</productname>程序本身时所作的那样。检查运行末尾附近的输出，应该看起来像这样：
 <screen>
 checking for xmllint... xmllint
-checking for DocBook XML V4.2... yes
+checking for DocBook XML V4.5... yes
 checking for dbtoepub... dbtoepub
 checking for xsltproc... xsltproc
 checking for fop... fop
@@ -483,7 +483,7 @@ ____________________________________________________________________________-->
 </screen>
     这也是默认的目标。这个命令的输出将出现在子目录<filename>html</filename>中。
    </para>
-   
+
 <!--==========================orignal english content==========================
    <para>
     To produce HTML documentation with the stylesheet used on <ulink
@@ -502,7 +502,19 @@ ____________________________________________________________________________-->
 <prompt>doc/src/sgml$ </prompt><userinput>make STYLE=website html</userinput>
 </screen>
    </para>
-  </sect2>
+
+<!--==========================orignal english content==========================
+   <para>
+    If the <literal>STYLE=website</literal> option is used, the generated HTML
+    files include references to stylesheets hosted on <ulink
+    url="https://www.postgresql.org/docs/current/">postgresql.org</ulink> and
+    require network access to view.
+   </para>
+____________________________________________________________________________-->
+   <para>
+    如果使用<literal>STYLE=website</literal>选项，生成的 HTML 文件包括对托管在<ulink url="https://www.postgresql.org/docs/current/">postgresql.org</ulink> 上的样式表的引用，需要网络访问来查看。
+   </para>
+ </sect2>
 
  <sect2>
 <!--==========================orignal english content==========================