题解 | #每类试卷得分前3名#

select
    tag,
    uid,
    ranking
from
    (
        select tag,uid,
        row_number() over (
            partition by tag
            order by max_score DESC,min_score DESC,uid DESC
        ) as ranking
        from(
            select uid,tag,max(score) as max_score,min(score) as min_score
            from exam_record join examination_info using(exam_id)
            group by uid,tag
        ) as t_uid_tag_score
    ) as t_uid_tag_score
where ranking<=3