题解 | #每个题目和每份试卷被作答的人数和次数#
每个题目和每份试卷被作答的人数和次数
https://www.nowcoder.com/practice/203d0aed8928429a8978185d9a03babc
select tid, uv, pv from ( select exam_id tid, count(distinct uid) uv, count(exam_id) pv from exam_record group by exam_id order by uv desc,pv desc ) a union all select tid, uv, pv from ( select question_id tid, count(distinct uid) uv, count(question_id) pv from practice_record group by question_id order by uv desc,pv desc ) b