题解 | #各用户等级的不同得分表现占比#

这个题比较简单，没什么说的。

select
    c.level,
    c.score_grade,
    format(count(1)/max(levelNum),3) as ratio
from 
(

    select
        b.level,
        (case when a.score >= 90 then '优'
        when a.score >=75 then '良'
        when a.score >= 60 then '中'
        else '差' end) as score_grade,
        count(1) over(partition by b.level) as levelNum
    from exam_record a join user_info b on a.uid = b.uid and a.submit_time is not null
) c

group by c.level,c.score_grade

order by c.level desc,ratio desc