你可以试试这段代码:
DECLARE @temp TABLE (ID INT, FromDate DATETIME, ToDate DATETIME)
INSERT INTO @temp (ID, FromDate, ToDate)
VALUES ( 1 , '2003-1-08 06:55:56' , '2005-5-08 06:55:56'),
( 2 , '2000-10-08 06:55:56' , '2008-7-08 06:55:56'),
( 3 , '2013-6-08 06:55:56' , '2015-1-08 06:55:56'),
( 4 , '2006-4-08 06:55:56' , '2011-3-08 06:55:56' )
SELECT
ID,
CONVERT(DATE, FromDate) AS FromDate,
CONVERT(DATE, ToDate) AS ToDate,
DATEDIFF(MONTH, FromDate, ToDate) AS [Difference IN Months]
INTO #tmp
FROM @temp
SELECT T1.ID AS ID1, T2.ID AS ID2, T2.ToDate, T1.[Difference IN Months] + T2.[Difference IN Months] AS [Difference IN Months]
INTO #tmp2
FROM #tmp T1
INNER JOIN #tmp T2
ON CAST(T1.ToDate AS DATE) = CAST(T2.FromDate AS DATE)
OR (YEAR(T1.ToDate) = YEAR(T2.FromDate) AND CAST(T1.ToDate AS DATE) < CAST(T2.FromDate AS DATE))
OR YEAR(T1.ToDate) = YEAR(T2.FromDate) - 1
DELETE #tmp WHERE ID IN (SELECT ID2 FROM #tmp2)
UPDATE #tmp
SET ToDate = (SELECT ToDate FROM #tmp2 WHERE #tmp.ID = ID1),
[Difference IN Months] = (SELECT [Difference IN Months] FROM #tmp2 WHERE #tmp.ID = ID1)
WHERE ID IN (SELECT ID1 FROM #tmp2)
SELECT
*,
ROW_NUMBER() OVER(ORDER BY FromDate) AS RF
INTO #tmp3
FROM #tmp
SELECT T1.ID AS ID1, T2.ID AS ID2, T1.ToDate
INTO #tmp4
FROM #tmp3 T1
INNER JOIN #tmp3 T2 ON T1.RF = T2.RF + 1
WHERE CAST(T1.FromDate AS DATE) < CAST(T2.ToDate AS DATE)
UPDATE #tmp
SET ToDate = (SELECT ToDate FROM #tmp4 WHERE #tmp.ID = ID2)
WHERE ID IN (SELECT ID2 FROM #tmp4)
DELETE #tmp WHERE ID IN (SELECT ID1 FROM #tmp4)
UPDATE #tmp
SET[Difference IN Months] = DATEDIFF(MONTH, FromDate, ToDate)
SELECT
ROW_NUMBER() OVER(ORDER BY FromDate) AS ID,
FromDate, ToDate, [Difference IN Months]
FROM #tmp
DROP TABLE #tmp
DROP TABLE #tmp2
DROP TABLE #tmp3
DROP TABLE #tmp4
结果:
ID FromDate ToDate Difference IN Months
===================================================
1 2000-10-08 2011-03-08 125
2 2013-06-08 2015-01-08 19