MySQL查询比较2个日期范围

Question

here's my data structure:

seasons
id  from         to           name      
----------------------------------------
1   2015-11-01   2015-12-15   season1   
2   2015-12-16   2015-12-30   season2   
3   2015-12-31   2016-01-20   season3   

rooms_free
id  from         to           room_id
----------------------------------------
1   2015-11-26   2015-11-30   1   
2   2015-12-19   2015-12-28   2
3   2015-12-22   2015-12-29   3

i need an sql query which will join both tables by date range returning the following result:

id_room  room_from    room_to      season_id    season_name
-------------------------------------------------------------
1        2015-11-26   2015-11-30   1            season1   
2        2015-12-19   2015-12-28   2            season2
3        2015-12-22   2015-12-29   2            season2

could this be done using normal statements or would i need a mysql function? any ideas?

ps: the really tricky part is when there's several seasons per room ..

Answer 1

This is the best explanation about overlaping data ranges

Determine Whether Two Date Ranges Overlap

SQL Fiddle Demo

SELECT rf.room_id as id_room ,
       rf.from as room_from,
       rf.to as room_to,
       s.id as season_id,
       s.name as season_name
FROM rooms_free rf
JOIN seasons s
  ON (rf.From <= s.to)  and  (rf.to >= s.from)

OUTPUT

| room_id |                       from |                         to | id |    name |
|---------|----------------------------|----------------------------|----|---------|
|       1 | November, 26 2015 00:00:00 | November, 30 2015 00:00:00 |  1 | season1 |
|       2 | December, 19 2015 00:00:00 | December, 28 2015 00:00:00 |  2 | season2 |
|       3 | December, 22 2015 00:00:00 | December, 29 2015 00:00:00 |  2 | season2 |

Answer 2

SELECT rooms_free.id as id_room, rooms_free.from as room_from , rooms_free.to as room_to, seasons.id as season_id, seasons.name as season_name FROM rooms_free join seasons on rooms_free. from >=seasons.from and rooms_free. to <=seasons.to

Answer 3

select rooms_free.id as id_room, rooms_free.from as room_from, rooms_free.to as room_to, seasons.id as season_id,  seasons.name as season_name
from rooms_free
join seasons
on ((rooms.from <= seasons.from) and (seasons.from <= rooms.to)) or ((seasons.from <= rooms.from) and (rooms.from <= seasons.to))

The statement above checks for strict overlapping. If there are several seasons per room, then you can use group by , having and group_concat .

Answer 4

Select rooms_free.id, rooms_free.from, rooms_free.to, seasons.id,       seasons.name 
from rooms_free , seasons 
where (rooms_free.from >= season.from and rooms_free.to <= seasons.to)