如何获取酒店预订系统中未预订房间的确切mysql查询？

Question

我正在用php和mysql做酒店预订系统的项目，我在下面创建了rooms表

room_no| roo_id | room_type
 D1     |  1     | Deluxe
 R1     |  2     | AC
 R2     |  3     | Non Ac
 C1     |  4     | Cottage

该表是关于房间的总数，它表示酒店的总房间数。

这是customer_booking表，

customer_id | Cust_name | email | Address | room_type | room_no| cost|check_in | check_out
1 | satyawan |ss@gmail.com| xy | AC       |  R1    |5000 | 2012-12-26|2012-12-30
2 |satyawan  |   lahu@gmail.com|unr  |  Non A/C | R6 |            20002012-01-01|2012-12-07
3 |satyawan  |   lahu@gmail.com|unr  |  Non A/C | R8 |            2013-01-01  |2013-01-10
4 |satyawan  |   lahu@gmail.com|unr  |  Non A/C | R9 |            2013-01-10 |2013-01-16
5 |satyawan  |   lahu@gmail.com|unr  |  Non A/C | R6 |            2013-01-01 |2013-01-20

我已经在这两个表的联接上触发查询，以查询未预订房间的排序数据。 查询在下面

SELECT *
FROM rooms 
LEFT JOIN customer_booking  
ON customer_booking.room_no = rooms.room_no
WHERE customer_booking.client_id IS NULL
OR (customer_booking.check_out >= 2013-01-01
AND customer_booking.check_in >= 2013-01-10)
OR (customer_booking.check_out <= 2013-01-01
AND customer_booking.check_out <= 2013-01-10)

但我只想要未预订房间的数据。 如果房间已经预订，则必须显示该房间在该日期已经预订。

我对此一无所知。

Answer 1

也许您正在寻找NOT IN 。

SELECT * FROM rooms AS r WHERE r.room_no NOT IN (
   SELECT cb.room_no FROM customer_booking AS cb WHERE your_checkin_constraints); 

Answer 2

尝试使用此查询。 如果最后一个字段room_customer_id为0，则该房间是空闲的，否则显示保留该房间的customer_id。

SELECT rooms.*,COALESCE(customer_booking.customer_id,0) room_customer_id
FROM rooms 
LEFT JOIN customer_booking  ON 
   (customer_booking.room_no = rooms.room_no)
   and 
   (
      ('2013-01-01' between customer_booking.check_in and customer_booking.check_out)
      or 
      ('2013-01-10' between customer_booking.check_in and customer_booking.check_out)
      or 
      (customer_booking.check_in between '2013-01-01' and '2013-01-10')
    )

Answer 3

    SELECT r.room,case when r.room_no is null then 'Available'
    else 'Not Available' end
    FROM rooms r
    LEFT JOIN customer_booking cb 
    ON cb.room_no = r.room_no
    AND cb.check_out <= cur_date()-1

Answer 4

这样尝试，然后您将获得尚未预订的d个房间

SELECT * FROM room r WHERE 
 not exists (
   SELECT cb.room_no FROM customer_booking cb where cb.room_no=r.room_no);