SQL166大厂面试真题

统计新用户的方法，判断用户最早登陆日期是否等于当前日期，是记为1。sum(if(new_user_time=time,1,0))

select time, count(distinct t1.uid)dau, round(sum(if(new_user_time=time,1,0))/count(distinct t1.uid) ,2)from

(

    select uid, date(in_time) as time from tb_user_log union

    select uid, date(out_time) as time from tb_user_log

)t1 join

(

    select uid, min(date(in_time))new_user_time from tb_user_log

    group by uid

)t2 using(uid)

group by time

order by time ASC