题解 | 统计每个学校的答过题的用户的平均答题数
统计每个学校的答过题的用户的平均答题数
https://www.nowcoder.com/practice/88aa923a9a674253b861a8fa56bac8e5
select user_profile.university, round(count(question_practice_detail.question_id) / count(distinct question_practice_detail.device_id) , 4) as avg_answer_cnt from question_practice_detail left join user_profile on question_practice_detail.device_id = user_profile.device_id group by user_profile.university order by user_profile.university
