Mysql排序和排名

Question

  

可能重复：
  Ranking joint positions in MySQL

我想通过排序获得用户的排名，我使用了以下mysql语句：

"SELECT u.uid,u.name,pn.value AS nick,(@rank:=@rank+1) as rank,CAST(pa.value AS SIGNED) AS solved,
    CAST(ps.value AS SIGNED) AS submissions FROM (SELECT @rank:=0) r,users u 
    LEFT JOIN profile_values pn ON u.uid=pn.uid AND pn.fid=1 
    LEFT JOIN profile_values pa ON u.uid=pa.uid AND pa.fid=4 
    LEFT JOIN profile_values ps ON u.uid=ps.uid AND ps.fid=5 
    WHERE status=1 ORDER BY solved desc,submissions"

它不起作用，它显示为uid。 谁能帮帮我？谢谢。