update prepare_transaction to revoke.sgml（6 files）

Author: chegong18

postgresql/doc/src/sgml/ref/prepare_transaction.sgml

@@ -74,17 +74,15 @@ ____________________________________________________________________________-->
 <!--==========================orignal english content==========================
   <para>
    Once prepared, a transaction can later be committed or rolled back
-   with <xref linkend="sql-commit-prepared"/>
-   or <xref linkend="sql-rollback-prepared"/>,
+   with <link linkend="sql-commit-prepared"><command>COMMIT PREPARED</command></link>
+   or <link linkend="sql-rollback-prepared"><command>ROLLBACK PREPARED</command></link>,
    respectively.  Those commands can be issued from any session, not
    only the one that executed the original transaction.
   </para>
 ____________________________________________________________________________-->
   <para>
-   一旦被准备好，事务稍后就可以分别用
-   <xref linkend="sql-commit-prepared"/>
-   或者<xref linkend="sql-rollback-prepared"/>提交或者回滚。可以从任何
-   会话而不仅仅是执行原始事务的会话中发出这些命令。
+   一旦被准备好，事务稍后就可以分别用<link linkend="sql-commit-prepared"><command>COMMIT PREPARED</command></link>或者<link linkend="sql-rollback-prepared"><command>ROLLBACK PREPARED</command></link>提交或者回滚。
+   可以从任何会话而不仅仅是执行原始事务的会话中发出这些命令。
   </para>
 
 <!--==========================orignal english content==========================
@@ -174,13 +172,12 @@ ____________________________________________________________________________-->
 
 <!--==========================orignal english content==========================
   <para>
-   This command must be used inside a transaction block. Use <xref
-   linkend="sql-begin"/> to start one.
+   This command must be used inside a transaction block. Use <link
+   linkend="sql-begin"><command>BEGIN</command></link> to start one.
   </para>
 ____________________________________________________________________________-->
   <para>
-   这个命令必须在一个事务块中使用。事务块用<xref
-   linkend="sql-begin"/>开始。
+   这个命令必须在一个事务块中使用。事务块用<link linkend="sql-begin"><command>BEGIN</command></link>开始。
   </para>
 
 <!--==========================orignal english content==========================