#计算日期需要+1，用timestampdiff函数

select 
user_id,room_id,room_type,timestampdiff(day,checkin_time,checkout_time)+1 as days
from guestroom_tb
join checkin_tb using(room_id)
where date(checkin_time) >= '2022-06-12'
and timestampdiff(day,checkin_time,checkout_time) > 0
order by 4,2,1 desc

#就是这个排序，呆的不谈，题目不说，完全根据答案修改的