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 qpd.device_id),4)
as avg_answer_cnt
from user_profile as up
inner join question_practice_detail as qpd
on up.device_id = qpd.device_id
group by university
order by university;
保留4位小数---->round函数；
按照大学升序---->order by university；
另外宣传下自己的开源仿b站微服务项目，GitHub已经390star，牛客上有完整文档教程