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
p.university,
count(d.question_id)/count(distinct d.device_id) as avg_answer_cnt
from
user_profile p
join question_practice_detail d on p.device_id = d.device_id
group by p.university
