题解 | #每类试卷得分前3名#

select
    tag tid,
    uid,
    ranking
from
    (
        select
            uid,
            tag,
            row_number() over (
                partition by
                    tag
                order by
                    max(score) desc,
                    min(score) desc,
                    max(uid) desc
            ) ranking
        from
            exam_record a
            left join examination_info b on a.exam_id = b.exam_id
        group by
            uid,
            tag
    ) a
where
    ranking <= 3
order by
    tid ,
    ranking