大家好,
我需要为房屋搜索创建一个查询,该查询将匹配数据库用户输入的数据:他们想要进入和离开的日期,他们在组中的人数和每晚的价格.
让我们说用户搜索了房子:
日期:2011-01-15至2011-03-01(见图片期A1C1),3人,他愿意每晚花费90至125美元.
这是我对此搜索的手动计算:
>数据库中可用的日期
>用户想要入住的日期总数为:44天
> 2011-01-15至2011-01-25第一期的价格是10天* 100美元= 1000美元
>第二期2011-01-25至2011-02-14的价格是20天* 120美元= 2400美元
>第二期2011-02-14至2011-03-01的价格是14天* 140美元= 1960美元
>每晚总平均价格= 1000 2400 1960/44 = $121.8
>价格和人数匹配用户输入,所以我们显示这个房子
如果合并日期并计算给定期间的每晚平均价格,则搜索脚本应与上面提供的数据数组匹配.
我的问题是:如果用户数据与数据库中的记录匹配,我的查询应如何快速计算.
我正在考虑使用SQL DATEDIFF函数,然后乘以价格等等,但它看起来相当复杂.
我将不胜感激任何建议.
谢谢
UPDATE
这是我的数据库架构:
表“apt_search_periods”,用于存储所有合并日期(可用性表中的连续日期)
+-----------+------------+------------+-----------+--------------+--------+
| period_id | start_date | end_date | rental_id | nb_of_people | merged |
+-----------+------------+------------+-----------+--------------+--------+
| 21 | 2011-03-31 | 2012-03-31 | 548 | 4 | y |
+-----------+------------+------------+-----------+--------------+--------+
表“apt_search_periods_avail”将合并日期与可用性表相关联
+----+-----------+-----------------+
| id | period_id | availability_id |
+----+-----------+-----------------+
| 21 | 21 | 20953 |
| 22 | 21 | 20952 |
| 23 | 21 | 4033 |
+----+-----------+-----------------+
表“可用性”,包含扩展日期和价格
+-------+-----------+------------+------------+--------------+--------------+
| id | rental_id | start_date | end_date | nb_of_people | rent_per_day |
+-------+-----------+------------+------------+--------------+--------------+
| 20952 | 548 | 2011-03-31 | 2011-07-01 | 4 | 575 |
| 4033 | 548 | 2011-07-01 | 2011-09-01 | 4 | 680 |
| 20953 | 548 | 2011-09-01 | 2012-03-31 | 4 | 575 |
+-------+-----------+------------+------------+--------------+--------------+
最佳答案 以下应该让你开始.
请注意,唯一的区别是根据DATEDIFF,第三个时期包括15天.
SQL语句
;WITH q AS (
/* Kick of with the record where startdate < input < enddate */
SELECT date_start
, date_end
FROM @HouseSearch
WHERE date_start <= @date_start
AND date_end >= @date_start
AND nb_people >= @nb_people -- Only when number of people is adequate
UNION ALL
SELECT q.date_start
, hs.date_end
FROM q
INNER JOIN @HouseSearch hs ON hs.date_start = q.date_end
WHERE nb_people >= @nb_people -- Only when number of people is adequate
)
SELECT *
FROM (
-- Only return result if sequence exists between date range
SELECT date_start = MIN(date_start)
, date_end = MAX(date_end)
FROM q
WHERE date_end >= @date_end
) datetimerange
-- Calculate the average price
CROSS APPLY (
SELECT [AveragePrice] = SUM(price / DATEDIFF(dd, @date_start, @date_end))
FROM (
-- Price for all records where date_end <= @date_end
SELECT [price] =
CASE WHEN @date_start < date_start
THEN DATEDIFF(dd, date_start, date_end) * price
ELSE DATEDIFF(dd, @date_start, date_end) * price
END
FROM @HouseSearch
WHERE @date_end > date_end
UNION ALL
-- Price of remaining records where date_end >= @date_end
SELECT DATEDIFF(dd, date_start, @date_end) * price
FROM @HouseSearch
WHERE @date_end between date_start AND date_end
) prices
) price
WHERE date_start IS NOT NULL
测试数据
DECLARE @HouseSearch TABLE (
date_start DATE
, date_end DATE
, nb_people INTEGER
, price FLOAT
)
INSERT INTO @HouseSearch VALUES
('2011-01-01', '2011-01-25', 4, 100)
, ('2011-01-25', '2011-02-14', 3, 120)
, ('2011-02-14', '2011-03-12', 3, 140)
, ('2011-03-12', '2011-04-10', 3, 100)
DECLARE @date_start DATE = '2011-01-15'
DECLARE @date_end DATE = '2011-03-01'
DECLARE @nb_people INTEGER = 3
DECLARE @price_low FLOAT = 90
DECLARE @price_high FLOAT = 15