题解 | 统计每个用户的平均刷题数
统计每个用户的平均刷题数
https://www.nowcoder.com/practice/f4714f7529404679b7f8909c96299ac4
select dx.university,level.difficult_level ,round(count(t1.question_id)/count(distinct t1.device_id),4)avg_answer_cnt from question_practice_detail as t1 left join user_profile as dx on t1.device_id=dx.device_id left join question_detail as level on t1.question_id=level.question_id where dx.university='山东大学' group by 1,2
