sql-server - 在开始/结束日期将记录拆分为多个记录

Question

我正在寻找一种解决方案，我必须使用另一个表中的数据从一个记录创建一组记录。表定义:

DECLARE A AS TABLE
(
 AID BIGINT NOT NULL,
 StartDate DATETIME NOT NULL,
 EndDate DATETIME
)

DECLARE B AS TABLE
(
 AID BIGINT NOT NULL,
 StartDate DATETIME NOT NULL,
 EndDate DATETIME NULL
)

这个想法是，当 A 包含:

1 | 01-01-2010 | 01-02-2010
2 | 01-10-2010 | 31-10-2010

B 包含:

1 | 01-01-2010 | 15-01-2010
2 | 15-10-2010 | 20-10-2010

我们收到 5 条记录:

1 | 01-01-2010 | 15-01-2010
1 | 16-01-2010 | 01-02-2010
2 | 01-10-2010 | 15-10-2010
2 | 16-10-2010 | 20-10-2010
2 | 21-10-2010 | 31-10-2010

目前，我们使用 A 上的游标和 B 上的内循环游标来执行此操作，我们必须在 SQLServer(TSQL 或最坏情况下的 CLR)中执行此操作

关于如何将其编写为选择以便光标的开销消失的任何想法？

Answer 1

DECLARE @A TABLE (AID BIGINT NOT NULL, StartDate DATETIME NOT NULL, EndDate DATETIME)
DECLARE @B TABLE (AID BIGINT NOT NULL, StartDate DATETIME NOT NULL, EndDate DATETIME NULL)

SET DATEFORMAT dmy
INSERT @A VALUES (1 ,'01-01-2010','01-02-2010')
INSERT @A VALUES (2 ,'01-10-2010','31-10-2010')
INSERT @B VALUES (1 ,'01-01-2010','15-01-2010')
INSERT @B VALUES (2 ,'15-10-2010','20-10-2010')

;WITH transitions as
(
    SELECT *, ROW_NUMBER() OVER (PARTITION BY AID ORDER BY startdate) Sequence
    FROM (
        SELECT A.AID, A.startdate
        FROM @a A
        UNION
        SELECT A.AID, B.startdate + 1
        FROM @A A
        INNER JOIN @b B ON B.startdate > A.startdate AND B.startdate < A.enddate
        UNION
        SELECT A.AID, B.enddate + 1
        FROM @A A
        INNER JOIN @b B ON B.enddate > A.startdate AND B.enddate < A.enddate
        UNION
        SELECT A.AID, A.enddate + 1
        FROM @a A
        WHERE A.enddate > A.startdate
    ) T
)   
SELECT T1.AID, T1.startdate startdate, T2.startdate - 1 enddate
FROM transitions T1
INNER JOIN transitions T2 ON T2.AID = T1.AID AND T2.Sequence = T1.Sequence + 1
ORDER BY T1.AID, T1.Sequence