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,count(question_id)/count(distinct qpd.device_id)
from
question_practice_detail qpd
left join
user_profile up
on
up.device_id = qpd.device_id
group by university
order by university asc;
结果没有统计 北理的 因为北理没答题 count(distinct qpd.device_id)这种写法也可以 记录
