MYSQL 临时表

SQL 处理group by order by 使用临时表

$sql="SELECT * FROM (SELECT r.id as rid,h.name as name,m.addtime as maddtime ,h.img as img,h.id as homesiteid FROM ".tablename('xx')." as u  ".    " LEFT JOIN ".tablename('xx')." as r on u.roomid=r.id ".    " LEFT JOIN ".tablename('xx')." as m on m.roomid=u.roomid ".    " LEFT JOIN ".tablename('xx')." as h on r.gid=h.id ".    " WHERE u.unionid='".$staffinfo['unionid']."' and u.wid=$wid  order by m.addtime DESC) as a group by a.rid ORDER by a.maddtime DESC";