题解 | #作答试卷得分大于过80的人的用户等级分布#
作答试卷得分大于过80的人的用户等级分布
http://www.nowcoder.com/practice/5bc77e3a3c374ad6a92798f0ead4c744
select level,count(distinct e.uid) as level_cnt
from exam_record e
join user_info u
on e.uid=u.uid
where e.exam_id IN
(
select exam_id
from examination_info
where tag="SQL"
) and e.score>80
group by level
order by level_cnt desc,level desc
