在由两列定义的范围内为每个月显示一行

Question

这是我有的表的一个例子：

Part No  | Start Date | End Date  |Cost
ABCD1    | 2014-01-01 | 2014-04-01|50.99
BDE2     | 2014-01-01 | 2014-03-01|14.59
ABCD1    | 2014-04-13 | 2014-05-01|13.99

这是我想看到的输出

Part No  | Start Date | End Date  |Cost   |Period
ABCD1    | 2014-01-01 | 2014-04-01|50.99  |2014/01
ABCD1    | 2014-01-01 | 2014-04-01|50.99  |2014/02
ABCD1    | 2014-01-01 | 2014-04-01|50.99  |2014/03
BDE2     | 2014-01-01 | 2014-03-01|14.59  |2014/01
BDE2     | 2014-01-01 | 2014-03-01|14.59  |2014/02
ABCD1    | 2014-04-13 | 2014-05-01|13.99  |2014/04

我想根据日期范围添加一定数量的行。此外，在每一行中添加基本上是月份和年份的列期间。

Answer 1

我建议创建一个日期表并将该表交叉连接到您的零件表，如下例所示。

这样做是tempdb为了不要踩到其他任何东西。

USE tempdb;

创建一个Months表，其中包含年、月和开始日期：

CREATE TABLE dbo.Months
(
    iYear int NOT NULL
    , iMonth int NOT NULL
    , dDate date NOT NULL
    , CONSTRAINT pk_Months
        PRIMARY KEY CLUSTERED
        (iYear, iMonth)
);

使用 CTE 将行填充到上表中。本示例在 1900-01-01 到 2173-10-01 的范围内创建年/月：

;WITH cte AS
(
    SELECT v.Num
    FROM (VALUES (0), (1), (2), (3), (4), (5), (6), (7), (8), (9))v(Num)
)
, cteDates AS 
(
    SELECT dDate = DATEADD(DAY, 0, ROW_NUMBER() OVER (ORDER BY c1.Num))
    FROM cte c1
        CROSS APPLY cte c2
        CROSS APPLY cte c3
        CROSS APPLY cte c4
        CROSS APPLY cte c5
)
, cteMonths AS
(
    SELECT iYear = DATEPART(YEAR, cteDates.dDate)
        , iMonth = DATEPART(MONTH, cteDates.dDate)
    FROM cteDates
)
INSERT INTO dbo.Months(iYear, iMonth, dDate)
SELECT cteMonths.iYear
    , cteMonths.iMonth
    , DATEFROMPARTS(cteMonths.iYear, cteMonths.iMonth, 1)
FROM cteMonths
GROUP BY cteMonths.iYear
    , cteMonths.iMonth
ORDER BY cteMonths.iYear
    , cteMonths.iMonth;

使用示例“零件”数据创建表：

CREATE TABLE dbo.PartCosts
(
    PartNum varchar(10) NOT NULL
    , StartDate date NOT NULL
    , EndDate date NOT NULL
    , Cost decimal(10,2) NOT NULL
);

INSERT INTO dbo.PartCosts(PartNum, StartDate, EndDate, Cost)
VALUES ('ABCD1', '2014-01-01', '2014-04-01', 50.99)
    , ('BDE2', '2014-01-01', '2014-03-01', 14.59)
    , ('ABCD1', '2014-04-01', '2014-05-01', 13.99);

运行交叉连接以获得您想要的结果：

SELECT pc.PartNum
    , pc.StartDate
    , pc.EndDate
    , pc.Cost
    , Period = CONVERT(varchar(7), m.dDate, 111)
FROM dbo.PartCosts pc
    CROSS JOIN dbo.Months m
WHERE pc.StartDate <= m.dDate
    AND pc.EndDate > m.dDate;

结果：

+---------+------------+------------+-------+----- ----+
| 零件编号 | 开始日期 | 结束日期 | 成本 | 期间 |
+---------+------------+------------+-------+----- ----+
| ABCD1 | 2014-01-01 | 2014-04-01 | 50.99 | 2014/01 |
| ABCD1 | 2014-01-01 | 2014-04-01 | 50.99 | 2014/02 |
| ABCD1 | 2014-01-01 | 2014-04-01 | 50.99 | 2014/03 |
| BDE2 | 2014-01-01 | 2014-03-01 | 14.59 | 2014/01 |
| BDE2 | 2014-01-01 | 2014-03-01 | 14.59 | 2014/02 |
| ABCD1 | 2014-04-01 | 2014-05-01 | 13.99 | 2014/04 |
+---------+------------+------------+-------+----- ----+

Answer 2

这是另一种方法。鉴于此表：

CREATE TABLE #PartCosts
(
  PartNo    varchar(32)   NOT NULL,
  StartDate date          NOT NULL,
  EndDate   date          NOT NULL,
  Cost      decimal(18,2) NOT NULL
);

INSERT #PartCosts(PartNo, StartDate, EndDate, Cost)
VALUES('ABCD1','2014-01-01','2014-04-01',50.99),
      ('BDE2 ','2014-01-01','2014-03-01',14.59),
      ('ABCD1','2014-04-01','2014-05-01',13.99);

我们只需要生成一系列等于最大月份差距的数字：

DECLARE @range int;
SELECT @range = MAX(DATEDIFF(MONTH, StartDate, EndDate)) FROM #PartCosts;

;WITH x(x) AS (SELECT 0 UNION ALL SELECT x+1 FROM x WHERE x <= (@range-1))
SELECT p.PartNo, p.StartDate, p.EndDate, p.Cost, 
  [Period] = CONVERT(char(7), DATEADD(MONTH, x.x, p.StartDate), 111)
FROM x CROSS JOIN #PartCosts AS p
WHERE p.EndDate > DATEADD(MONTH, x.x, p.StartDate)
ORDER BY p.StartDate, p.PartNo
OPTION (MAXRECURSION 0);

MAXRECURSION仅当您的范围跨越 100 个月以上时才需要该选项，但安全总比抱歉好。