题解 | #某乎问答11月份日人均回答量#
某乎问答11月份日人均回答量
https://www.nowcoder.com/practice/d1f5a1e50d0b49f3a39eb01c4fdb621f
select answer_date, round(count(*)/count(distinct author_id),2) as per_num from answer_tb group by answer_date order by answer_date
不理解为什么issue_id不用去重 但是answer_id需要