题解 | #牛客每个人最近的登录日期(三)#

select
        round((sum(case when t2.date is not null then 1 else 0 end)/count(*)),3)
from
                login   t1
    left join   login   t2  on t1.user_id = t2.user_id and  t2.date = date_add(t1.date,interval 1 day)   
where
        t1.date = (
            select
                        
                        min(date)
            from
                        login  
            where
                        user_id = t1.user_id
        )       -- 获取每个用户最新登陆时间