题解 | 每篇文章同一时刻最大在看人数

with t1 as(
    select artical_id,
    in_time as mytime,
    1 as uv
    from tb_user_log
    union all
    select artical_id,
    out_time as mytime,
    -1 as uv
    from tb_user_log
),
t2 as(
    select artical_id,
    sum(uv) over(partition by artical_id order by mytime asc,uv desc) as tmp_uv
    from t1
    where artical_id!=0
)
select artical_id,
max(tmp_uv) as max_uv
from t2
group by artical_id
order by max_uv desc