采用虚拟表做的，可拓展空间大。请大佬多多指教，先做出来最早登录的时间和人，在求出来每天登录时间的和人（虚拟表）
在求出来两个虚拟表相连，并把条件写出来因注册日=注册日，所以，要建立相连。再求出来注册人数，用count(distinct uid)求出来当天活跃人数 一除以就行了
with  date1 as 
(
select  uid,date(min(in_time)) as  first_date from tb_user_log
group by uid
)
,date2 as 
(
select uid,date(in_time) as time1 from tb_user_log
union 
select uid,date(out_time) as  time1 from tb_user_log
group by uid,time1
)


select
t1.time1,
duid,
round(
day0/duid,2) as cnt
from 
(
select
t.time1,
sum(case when t.diff=0 then 1 else 0 end ) as day0,
count(distinct uid) as  duid
from
(SELECT
 date1.first_date,
 date2.uid,
 date2.time1,
 datediff(date2.time1,date1.first_date) as diff
from date2 left join date1 on date2.uid=date1.uid and date1.first_date=date2.time1
) as t
group by t.time1
) as t1
order by t1.time1 asc