题解 | #牛客每个人最近的登录日期(五)#

select
    date,
    round(if(sum(new_user) != 0,
    sum(
        case
        when new_user=1 and lc=1 then 1
        else 0 end
	)/sum(new_user), 0), 3)
from(
    select
        *,
        if (date = min(date) over (partition by user_id), 1, 0) as new_user,
        if (datediff(Lead(date, 1)over(partition by user_id order by date), date) = 1, 1, 0) as lc
    from
        login
    ) t1
group by date