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
university,round(count(question_id)/count(distinct q.device_id),4)avg_answer_cnt
from
question_practice_detail q
inner join
user_profile u
on
q.device_id = u.device_id
group by
university
order by
university
