move.sgml

来自「postgresql8.3.4源码,开源数据库」· SGML 代码 · 共 105 行

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$PostgreSQL: pgsql/doc/src/sgml/ref/move.sgml,v 1.30 2006/09/16 00:30:19 momjian Exp $
PostgreSQL documentation
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<refentry id="SQL-MOVE">
 <refmeta>
  <refentrytitle id="SQL-MOVE-TITLE">MOVE</refentrytitle>
  <refmiscinfo>SQL - Language Statements</refmiscinfo>
 </refmeta>

 <refnamediv>
  <refname>MOVE</refname>
  <refpurpose>position a cursor</refpurpose>
 </refnamediv>

 <indexterm zone="sql-move">
  <primary>MOVE</primary>
 </indexterm>

 <indexterm zone="sql-move">
  <primary>cursor</primary>
  <secondary>MOVE</secondary>
 </indexterm>

 <refsynopsisdiv>
<synopsis>
MOVE [ <replaceable class="PARAMETER">direction</replaceable> { FROM | IN } ] <replaceable class="PARAMETER">cursorname</replaceable>
</synopsis>
 </refsynopsisdiv>

 <refsect1>
  <title>Description</title>

  <para>
   <command>MOVE</command> repositions a cursor without retrieving any data.
   <command>MOVE</command> works exactly like the <command>FETCH</command>
   command, except it only positions the cursor and does not return rows.
  </para>

  <para>
   Refer to 
   <xref linkend="sql-fetch" endterm="sql-fetch-title">
   for details on syntax and usage.
  </para>
 </refsect1>

 <refsect1>
  <title>Outputs</title>

  <para>
   On successful completion, a <command>MOVE</> command returns a command
   tag of the form
<screen>
MOVE <replaceable class="parameter">count</replaceable>
</screen>
   The <replaceable class="parameter">count</replaceable> is the number
   of rows that a <command>FETCH</command> command with the same parameters
   would have returned (possibly zero).
  </para>
 </refsect1>

 <refsect1>
  <title>Examples</title>

<programlisting>
BEGIN WORK;
DECLARE liahona CURSOR FOR SELECT * FROM films;

-- Skip the first 5 rows:
MOVE FORWARD 5 IN liahona;
MOVE 5

-- Fetch the 6th row from the cursor liahona:
FETCH 1 FROM liahona;
 code  | title  | did | date_prod  |  kind  |  len
-------+--------+-----+------------+--------+-------
 P_303 | 48 Hrs | 103 | 1982-10-22 | Action | 01:37
(1 row)

-- Close the cursor liahona and end the transaction:
CLOSE liahona;
COMMIT WORK;
</programlisting>
 </refsect1>

 <refsect1>
  <title>Compatibility</title>

  <para>
   There is no <command>MOVE</command> statement in the SQL standard.
  </para>
 </refsect1>

 <refsect1>
  <title>See Also</title>

  <simplelist type="inline">
   <member><xref linkend="sql-close" endterm="sql-close-title"></member>
   <member><xref linkend="sql-declare" endterm="sql-declare-title"></member>
   <member><xref linkend="sql-fetch" endterm="sql-fetch-title"></member>
  </simplelist>
 </refsect1>
</refentry>