在选择房间可用性时使用 MySQL 查询

Question

我在酒店预订中的房间可用性方面有这个数据库结构

下面是我的room表格

room_num    roomtype     
101         Single    
102         Single    
103         Single    
111         Deluxe    
112         Deluxe   
113         Deluxe    
114         Deluxe    
115         Deluxe    
116         Deluxe    
121         Superior  
122         Superior  

下面的表格是room_booked是记录预订房间号

dor 是入住日期，dco 是退房日期

room_num        dor         dco
  111        2014-06-01  2014-06-06
  112        2014-06-01  2014-06-06
  113        2014-06-01  2014-06-06
  114        2014-06-01  2014-06-06
  115        2014-06-01  2014-06-06
  116        2014-06-01  2014-06-06
  112        2014-05-18  2014-05-21
  113        2014-08-01  2014-08-04

在这种情况下，所有豪华客房都从2014-06-01 预订到2014-06-06。然后我使用下面的 MySQL 代码选择了 2014-06-01 至 2014-06-06 可用的豪华房

SELECT
    room.room_num
FROM
    room
LEFT JOIN
    room_booked ON room_booked.room_num = room.room_num
WHERE
    (
        (
            dor IS NULL AND dco IS NULL
        )
        OR (
            -- wished booking date is before DOR
            '2014-06-06' < dor
            -- OR wished booking date is after DCO
            OR '2014-06-01' >=  dco
        )
    )
    -- room type
    AND roomtype = 'Deluxe'

但它显示的是豪华房号。 112 和 113 在上述选定日期范围之前和之后预订，而不是 0 或完全预订。有没有办法修复这个代码？

Answer 1

我认为您必须检查入住和退房的两个日期：

SELECT
    room.room_num
FROM
    room
WHERE
  roomtype = 'Deluxe' AND
  room.room_num not in 
  (
    SELECT
      room_booked.room_num
    FROM
      room_booked
    WHERE
      (room_booked.dor<='2014-06-1' and room_booked.dco>='2014-06-1')
      OR
      (room_booked.dor<'2014-06-06' and room_booked.dco>='2014-06-06')
      OR
      (room_booked.dor>='2014-06-01' and room_booked.dco<'2014-06-06')
   )

重新编辑答案并创建sqlfiddle 用于测试