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 b.artical_id,
max(b.cnt) as max_uv
from
(select a.artical_id,
sum(a.knub) over (partition by a.artical_id order by a.dt asc,a.knub desc) as cnt
from
(select artical_id,
in_time as dt,
1 as knub
from tb_user_log
where artical_id != 0
union all
select artical_id,
out_time as dt,
-1 as knub
from tb_user_log
where artical_id != 0 ) a) b
group by b.artical_id
order by max_uv desc
