合并和重组日期范围 (SQL)

Question

我有三张表：每种类型的服务一张。每个表格都列出了客户在不同日期期间对该特定服务的价格：

TABLE: SERVICE_A
 | StartDate    | EndDate      | Price  |
 ----------------------------------------
 | 01/01/2013   | 16/04/2013   | 30     |
 | 17/04/2013   | 20/09/2013   | 33     |
 | 21/09/2013   | 31/12/2013   | 34     |


TABLE: SERVICE_B
 | StartDate    | EndDate      | Price  |
 ----------------------------------------
 | 01/01/2013   | 30/06/2013   | 47     |
 | 01/07/2013   | 31/12/2013   | 49     |


TABLE: SERVICE_C
 | StartDate    | EndDate      | Price  |
 ----------------------------------------
 | 01/01/2013   | 03/03/2013   | 96     |
 | 04/03/2013   | 31/12/2013   | 101    |

我正在尝试创建一个表格来合并这些数据并对其进行重组以显示适当日期范围内所有三种服务的价格：

RESULTS
 | StartDate    | EndDate      | PriceA | PriceB | PriceC |
 ----------------------------------------------------------
 | 01/01/2013   | 03/03/2013   | 30     | 47     | 96     |
 | 04/03/2013   | 16/04/2013   | 30     | 47     | 101    |
 | 17/04/2013   | 30/06/2013   | 33     | 47     | 101    |
 | 01/07/2013   | 20/09/2013   | 33     | 49     | 101    |
 | 21/09/2013   | 31/12/2013   | 34     | 49     | 101    |

对于此查询的任何帮助将不胜感激！ （我使用的是 SQL Server 2008 R2）。

Answer 1

这是一个可怕的解决方案，但它不使用光标：D

首先，我需要将您的数据放入表变量中，以便进行测试。

DECLARE @ServiceA TABLE (
    StartDate DATE,
    EndDate DATE,
    Price INT);
INSERT INTO @ServiceA VALUES ('2013-01-01', '2013-04-16', 30);
INSERT INTO @ServiceA VALUES ('2013-04-17', '2013-09-20', 33);
INSERT INTO @ServiceA VALUES ('2013-09-21', '2013-12-31', 34);
DECLARE @ServiceB TABLE (
    StartDate DATE,
    EndDate DATE,
    Price INT);
INSERT INTO @ServiceB VALUES ('2013-01-01', '2013-06-30', 47);
INSERT INTO @ServiceB VALUES ('2013-07-01', '2013-12-31', 49);
DECLARE @ServiceC TABLE (
    StartDate DATE,
    EndDate DATE,
    Price INT);
INSERT INTO @ServiceC VALUES ('2013-01-01', '2013-03-03', 96);
INSERT INTO @ServiceC VALUES ('2013-03-04', '2013-12-31', 101);

现在我可以编写一个可怕的查询，以您想要的方式提取数据：

WITH DistinctDates AS (
    SELECT
        StartDate,
        EndDate
    FROM
        @ServiceA
    UNION
    SELECT
        StartDate,
        EndDate
    FROM
        @ServiceB
    UNION
    SELECT
        StartDate,
        EndDate
    FROM
        @ServiceC),
OrderedDates AS (
    SELECT
        ROW_NUMBER() OVER (PARTITION BY StartDate ORDER BY EndDate) AS StartNumber,
        ROW_NUMBER() OVER (PARTITION BY EndDate ORDER BY StartDate DESC) AS EndNumber,
        *
    FROM
        DistinctDates),
FixOverlaps AS (
    SELECT
        CASE WHEN o2.StartNumber IS NULL THEN o1.StartDate ELSE DATEADD(DAY, 1, o2.EndDate) END AS StartDate,
        CASE WHEN o3.EndNumber IS NULL THEN o1.EndDate ELSE DATEADD(DAY, -1, o3.StartDate) END AS EndDate
    FROM
        OrderedDates o1
        LEFT JOIN OrderedDates o2 ON o2.StartDate = o1.StartDate AND o2.StartNumber = o1.StartNumber - 1
        LEFT JOIN OrderedDates o3 ON o3.EndDate = o1.EndDate AND o3.EndNumber = o1.EndNumber - 1),
MergeDates AS (
    SELECT
        StartDate,
        EndDate,
        ROW_NUMBER() OVER (PARTITION BY StartDate ORDER BY EndDate) AS MergeNumber
    FROM
        FixOverlaps)
SELECT 
    md.StartDate,
    md.EndDate,
    a.Price,
    b.Price,
    c.Price
FROM 
    MergeDates md
    LEFT JOIN @ServiceA a ON a.StartDate <= md.EndDate AND a.EndDate >= md.StartDate
    LEFT JOIN @ServiceB b ON b.StartDate <= md.EndDate AND b.EndDate >= md.StartDate
    LEFT JOIN @ServiceC c ON c.StartDate <= md.EndDate AND c.EndDate >= md.StartDate
WHERE 
    md.MergeNumber = 1;

...结果是：

StartDate   EndDate     PriceA  PriceB  PriceC
2013-01-01  2013-03-03  30      47      96
2013-03-04  2013-04-16  30      47      101
2013-04-17  2013-06-30  33      47      101
2013-07-01  2013-09-20  33      49      101
2013-09-21  2013-12-31  34      49      101

Answer 2

应该这样做。我正在考虑在开始日期您拥有所有三个价格：

CREATE TABLE #Services (
    StartDate DATETIME
    , EndDate DATETIME
    , PriceA INT
    , PriceB INT
    , PriceC INt
)

DECLARE @startDt DateTime, @endDt DateTime, @Price Int, @Service Char(1)
DECLARE @PriceA Int, @PriceB Int, @PriceC Int, @previousStartDate DateTime, @finalEndDate DateTime
SET @previousStartDate = '20130101'

DECLARE cursorDatePrices CURSOR FOR
SELECT StartDate, EndDate, Price, 'A' as Service
FROM #SA
UNION ALL
SELECT StartDate, EndDate, Price, 'B' as Service
FROM #SB
UNION ALL
SELECT StartDate, EndDate, Price, 'C' as Service
FROM #SC
ORDER BY StartDate

OPEN cursorDatePrices

FETCH NEXT FROM cursorDatePrices
INTO @startDt, @endDt, @Price, @Service

WHILE @@FETCH_STATUS = 0
BEGIN
    --only insert after having the three prices
    IF (@PriceA IS NOT NULL AND @PriceB IS NOT NULL AND @PriceC IS NOT NULL)
    BEGIN
        INSERT INTO #Services VALUES (@previousStartDate, DATEADD(dd, -1, @startDt), @PriceA, @PriceB, @PriceC)
        SET @previousStartDate = @startDt
    END

    IF (@Service = 'A') SET @PriceA = @Price
    ELSE IF (@Service = 'B') SET @PriceB = @Price
    ELSE IF (@Service = 'C') SET @PriceC = @Price

    FETCH NEXT FROM cursorDatePrices
    INTO @startDt, @endDt, @Price, @Service
END

CLOSE cursorDatePrices
DEALLOCATE cursorDatePrices

INSERT INTO #Services VALUES (@previousStartDate, @endDt, @PriceA, @PriceB, @PriceC)
SELECT * from #Services