体育馆:https://leetcode-cn.com/problems/human-traffic-of-stadium/
601.png
with tmp as(
select case when @pre+1=b.id then @r else @r:=@r+1 end id1,b.id,b.visit_date,b.people,@pre:=b.id
from (select @r:=0,@pre:=0) as init,(select * from Stadium where people>=100)b
)
select b.id,b.visit_date,b.people
from (
select id1 from tmp group by id1 having count(*)>=3
)a left join tmp b on a.id1=b.id1
order by b.visit_date
