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选择随机浏览量,并在同一询问中加以更新?
原标题:Select random rows and update them in the same query?
  • 时间:2011-10-17 16:52:32
  •  标签:
  • mysql

基本上,我想在一次提问中做以下工作。 是否可能?

$q = mysql_query( select * from table ORDER BY rand() LIMIT 5 );
$s;
while($r = mysq_fetch_array($q)){
    $s[i] = $r[ id ];
    // Do stuff
}
$u = mysql_query("update table SET lastUpdated = NOW() where id in (".implode( , ,$s).")");
最佳回答

你可以在同一询问中利用同一表格的选定/最新发言。

问题回答

你可以补充

ORDER BY RAND() LIMIT 5

结束您的更新询问

EDIT:

我首先忽略了问题的一部分。 如果您需要更新5个随机浏览量,上述工作将继续下去。 然而,它认为需要从您的桌上获得5个随机身份证,与这些身份证一起采取某些行动,并更新这些行文。 遗憾的是,人口基金的查询能够修改数据,而选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、选举、 你也许会建立某种储存的程序,更新/选择5个随机浏览器,但这比你目前提出的2个询问更加复杂。

EDIT #2:

If your reason for wanting to do this in the same query is concurrency, you could check out MySQL s Locking Read feature.





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