查询返回比指定范围早或晚 3 天的可用酒店房间

Question

我想返回酒店预订系统中的可用房间。 查询应返回比指定日期范围早或晚 3 天的结果。

数据库结构：

房间表（RoomID、RoomType、BedsNo、ViewAvailable...） 预订表（ReservationID、RoomID、CheckinDate、CheckoutDate...）

我正在使用以下查询返回指定日期范围内的可用房间：DateFrom 和 DateTo。 但是，如何返回比日期范围 DateFrom 和 DateTo 早或晚 3 天的结果。

select * from room 
where room.roomId not in
(select reservation.roomId from reservation where 
  (reservation.check_in_date <= `FromDate` AND reservation.check_out_date >= `ToDate`) 
           OR (reservation.check_in_date < `FromDate` AND reservation.check_out_date >= `ToDate`) 
           OR (`FromDate` <= reservation.check_in_date AND `ToDate` >= reservation.check_out_date))

Answer 1

你不能通过类似的方式为FromDate和ToDate添加 3 天

[...]
where reservation.check_in_data <= date_sub(FromDate, interval 3 day) 
and reservation.check_out_date >= date_add(ToDate, interval 3 day)
[...]

Answer 2

使用间隔

select * from room 
where room.roomId not in
(select reservation.roomId from reservation where 
  (reservation.check_in_date <= `FromDate` - INTERVAL 3 DAY AND reservation.check_out_date >= `ToDate` + INTERVAL 3 DAY) 
           OR (reservation.check_in_date < `FromDate` - INTERVAL 3 DAY AND reservation.check_out_date >= `ToDate` + INTERVAL 3 DAY) 
           OR (`FromDate` - INTERVAL 3 DAY <= reservation.check_in_date AND `ToDate` + INTERVAL 3 DAY >= reservation.check_out_date))