题解 | #每篇文章同一时刻最大在看人数#

with t1 as(select uid,artical_id,in_time as time,1 as person from tb_user_log
where artical_id<>0
union all
select uid,artical_id,out_time as time,-1 as person from tb_user_log
where artical_id<>0
order by time,person desc),
t2 as (select *,sum(person) over(partition by artical_id order by time,person desc) as uv from t1)
select artical_id,max(uv) as max_uv from t2 group by artical_id order by max_uv desc