T-SQL Calcola la durata in mesi tra diversi anni di intervalli

Question

Ho una tabella in SQL Server che contiene la durata di un utente che lavora per lavori diversi. Devo calcolare il numero totale di esperienze per l'utente.

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 * FROM @temp 

Desidero calcolare il numero totale di esperienze;

Id FromDate ToDate  Difference IN Months 
=================================================== 
1 2003-01-08 2005-05-08 28 
2 2000-10-08 2008-07-08 93 
3 2013-06-08 2015-01-08 19 
4 2006-04-08 2011-03-08 59 

dopo aver rimosso gli anni sovrapposti come nel 2003-2005 coperti nel 2000-2008; Ho qualcosa di simile:

Id FromDate ToDate  Difference IN Months 
===================================================  
1 2000-10-08 2011-03-08 125 
2 2013-06-08 2015-01-08 19 

Quindi la risposta sarebbe 125+19 = 144 mesi. Per favore aiutami a trovare una soluzione.

Answer 1

La sintassi qui è la ricerca di tutti i FromDate che non hanno un intervallo FromDate e ToDate sovrapposti e tutti gli ToDate che non hanno un intervallo FromDate e ToDate sovrapposti. Dando loro un RowNumber in base al valore di data e abbinandoli su quel RowNumber:

;WITH CTE as 
(
    SELECT min(Id) Id ,FromDate, row_number() over (ORDER BY FromDate) rn 
    FROM @temp x 
    WHERE 
    not exists 
     (SELECT * FROM @temp WHERE x.FromDate > FromDate and x.FromDate <= Todate) 
    GROUP BY FromDate 
), CTE2 as 
(
    SELECT Max(Id) Id ,ToDate, row_number() over (ORDER BY ToDate) rn 
    FROM @temp x 
    WHERE 
    not exists 
     (SELECT * FROM @temp WHERE x.ToDate >= FromDate and x.ToDate < Todate) 
    GROUP BY ToDate 
) 
SELECT SUM(DateDiff(month, CTE.FromDate, CTE2.ToDate)) 
FROM CTE 
JOIN CTE2 
ON CTE.rn = CTE2.rn 

Risultato:

144 

Answer 2

si può provare questo

SELECT Set1.FromDate,MIN(List1.ToDate) AS ToDate, DATEDIFF(MONTH,Set1.FromDate,MIN(List1.ToDate)) 
    FROM @temp Set1 
    INNER JOIN @temp List1 ON Set1.FromDate <= List1.ToDate 
    AND NOT EXISTS(SELECT * FROM @temp List2 

    WHERE List1.ToDate >= List2.FromDate AND List1.ToDate < List2.ToDate) 
    WHERE NOT EXISTS(SELECT * FROM @temp Set2 
    WHERE Set1.FromDate > Set2.FromDate AND Set1.FromDate <= Set2.ToDate) 

    GROUP BY Set1.FromDate 
    ORDER BY Set1.FromDate 

Answer 3

Si può provare questo codice:

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 

Risultato:

ID FromDate ToDate  Difference IN Months 
===================================================  
1 2000-10-08 2011-03-08 125 
2 2013-06-08 2015-01-08 19