mysql根据成绩排名次

1.（1，2，2，4 , 5）
select t.score,(select count(s.score)+1 from score s where s.score>t.score) rank from score t order by t.score desc;
2
（1，2，2，3 , 3）
select t.score,(select count(s.score)+1 from (select s.score,count(s.score) from score s group by score order by score desc) s where s.score>t.score) rank from score t order by t.score desc;
 
3. （1,2,3,4,5,6）自增序号

SELECT @rownum:=@rownum+1 AS xh, t.* FROM ( select * from test )t ,(SELECT @rownum:=0) r ;