题解 | #每篇文章同一时刻最大在看人数#
每篇文章同一时刻最大在看人数
https://www.nowcoder.com/practice/fe24c93008b84e9592b35faa15755e48
select artical_id,max(num) from( select artical_id,sum(n) over(partition by artical_id order by t,n desc) num #默认是从第一行开始 from( select artical_id,in_time t, 1 n from tb_user_log union all select artical_id,out_time t,-1 n from tb_user_log ) a where artical_id!=0 )b group by artical_id order by max(num) desc #默认排序是asc