Question

这是一个酒店代理的示例程序，他从各个酒店获得合同，并允许客户搜索和预订他与之签订合同的酒店（从而获得一些利润）。这是我的表格模式。

CONTRACT (contract_id, hotel_id, valid_from, valid_to) 
ROOM (room_type, hotel_id, contract_id, price, max_adults_allowed, avail_rooms)
HOTEL (hotel_id, hotel_name, location)

用于搜索，界面如hotels.com;即，例如，顾客可以指定它为“1个房间有2个成人”和“1个房间2个成人和1个房间3个成人”。

到目前为止，这是我的SQL查询，

select h.name, h.location, r.type, r.price FROM HOTEL h, ROOM r, CONTRACT c 
WHERE c.contract_id = r.contract_id and c.hotel_id = h.hotel_id    --table joining
AND 'requested room lies within the contract valid period'  --check in and check out dates comparison
AND 'h.location is the user specified location' --requested location 
........

我无法将房间搜索详情（如上所述）整合到此查询中。有人可以帮我写sql查询以包含房间规格。我正在使用SQL Server。提前谢谢。

Answer 1

假设您已经解析了“自然语言”输入，请通过max_adults对请求进行分组，然后查询每个单独的类型;例如'2个房间1个成人和3个房间2个成人'发出两个单独的查询（max_adults = 1，avail_rooms = 2）和（max_adults = 2，avail_rooms = 3）

select h.name, h.location, r.type, r.price, r.room_id FROM HOTEL h, ROOM r, CONTRACT c 
WHERE c.contract_id = r.contract_id and c.hotel_id = h.hotel_id
AND c.valid_from >= ? AND c.valid_to <= ? AND h.location = ?
AND r.max_adults = ? AND r.avail_rooms >= ?

请注意，这只会找到max_adults的完全匹配，并且不会为您提供“预订”房间的选项。如果您想允许客户预订大房间（并相应地支付，而不填写），您可以使用以下策略：首先尝试原始查询，然后搜索更大的房间（通过添加“人工客人”）。

例如，如果原始请求是'1 triple，1 double，1 single'，请先尝试，然后'1 triple 2 double'，然后'2 triples 1 double'，然后'3 triples'。对于每个“已修改”的查询，请使用上面的SQL。第一个成功的将是客户最便宜的选择。

即使这涉及多个SQL事务，每个事务都有简单的连接，并且可能比复杂的语句更快。

如果您有更多控制权，您可能会更改架构以分别考虑每个房间：

ROOM (room_id, room_type, hotel_id, contract_id, price, max_adults_allowed)
BOOKING (room_id, checkin, checkout)

Answer 2

此脚本检索只有必需房间的酒店。如果酒店只有一个必要的房间，则不包括酒店。

更新15.01.2013

IF OBJECT_ID('tempdb.dbo.#RoomParams') IS NOT NULL DROP TABLE dbo.#RoomParams
SELECT SUM(rooms) AS rooms, adults
INTO dbo.#RoomParams
FROM (VALUES(1, 2), -- 1 room with 2 adults
            (1, 2), -- 1 room with 2 adults
            (1, 3)) -- 1 room with 3 adults
p(rooms, adults)
GROUP BY adults

;WITH cte AS
 (
  SELECT h.hotel_id, h.hotel_name, h.location, r.room_type, r.price,
         SUM(avail_rooms) OVER (PARTITION BY h.hotel_id, r.max_adults_allowed) AS cnt,
         r.max_adults_allowed        
  FROM CONTRACT c JOIN ROOM r ON c.contract_id = r.contract_id AND c.hotel_id = r.hotel_id
                  JOIN HOTEL h ON c.hotel_id = h.hotel_id
  WHERE c.valid_from >= '20130114' AND c.valid_to <= '20130115'  --check in and check out dates comparison
        AND h.location IN ('loc4') --requested location        
  )
  SELECT *
  FROM cte s
  WHERE 
    NOT EXISTS (                  
                SELECT rp.adults
                FROM dbo.#RoomParams rp
                EXCEPT
                SELECT st.max_adults_allowed
                FROM cte st JOIN dbo.#RoomParams r ON st.cnt >= r.rooms AND st.max_adults_allowed = r.adults
                WHERE st.hotel_id = s.hotel_id                  
                ) AND s.max_adults_allowed IN (SELECT adults FROM dbo.#RoomParams)

SQLFiddle上的演示

如果您想要检索所有至少有一个选项的酒店

IF OBJECT_ID('tempdb.dbo.#RoomParams') IS NOT NULL DROP TABLE dbo.#RoomParams
SELECT rooms, adults
INTO dbo.#RoomParams
FROM (VALUES(1, 2), -- 1 room with 2 adults
            (1, 2), -- 1 room with 2 adults
            (1, 3)) -- 1 room with 3 adults
p(rooms, adults)

;WITH cte AS
 (
  SELECT h.hotel_id, h.hotel_name, h.location, r.room_type, r.price,
         SUM(avail_rooms) OVER (PARTITION BY h.hotel_id, r.max_adults_allowed) AS cnt,
         r.max_adults_allowed
  FROM CONTRACT c JOIN ROOM r ON c.contract_id = r.contract_id AND c.hotel_id = r.hotel_id
                  JOIN HOTEL h ON c.hotel_id = h.hotel_id
  WHERE c.valid_from >= '20130114' AND c.valid_to <= '20130115'  --check in and check out dates comparison
        AND h.location IN ('loc4') --requested location
  )
  SELECT hotel_name, location, room_type, price, max_adults_allowed, cnt
  FROM cte c 
  WHERE EXISTS (
                SELECT 1
                FROM dbo.#RoomParams r 
                WHERE c.cnt >= r.rooms AND c.max_adults_allowed = r.adults
                )

房间搜索SQL查询

2 个答案: