题解 | #每类试卷得分前3名#
每类试卷得分前3名
https://www.nowcoder.com/practice/255aa1863fe14aa88694c09ebbc1dbca
select tag as tid,uid,ranking from ( select tag,exam_record.uid, row_number() over(partition by tag order by max(score) desc,min(score) desc,exam_record.uid desc) as ranking from exam_record left join examination_info using(exam_id) group by tag,exam_record.uid) a where ranking <= 3
row_number窗口函数的应用，按照标签分组，按照最高分数、最低分数、uid排序得到排名，取出前三名作为最终结果
