题解 | #牛客每个人最近的登录日期(四)#

with
    t2 as (
        select
            l.*,
            if (l.date = t1.date, 1, null) as is_one
        from
            login as l
            left join (
                select
                    user_id,
                    min(date) as date
                from
                    login
                group by
                    user_id
            ) as t1 on l.user_id = t1.user_id
    )
select
    date,
    count(is_one) as new
from
    t2
group by
    date
order by
    date