如何计算两个日期之间的天数以及多个日期的总天数

你可以用这个。

;WITH CTE AS 
(
    SELECT *, 
    RN = ROW_NUMBER() OVER (PARTITION BY Name, Status ORDER BY [Date]) 
    FROM DataSet
)
SELECT 
    T1.Name Person,  
    SUM(DATEDIFF(DAY,T1.Date, T2.Date)) -1 [Number of Uncleared Days] 
FROM CTE T1 INNER JOIN CTE T2 ON T1.Name = T2.Name AND T2.Status ='Cleared' AND T1.RN = T2.RN 
WHERE T1.Status ='Uncleared'
GROUP BY T1.Name

SELECT Person, SUM([Date_Diff]) - 1 AS [Number of Uncleared Days]  FROM
( 
    SELECT 
        D1.Name AS Person, 
        DATEDIFF(DAY, [Date] , 
            (SELECT TOP 1 [Date] 
            FROM DataSet D2 
            WHERE D2.Status ='Cleared' 
                AND D1.Name = D2.Name 
                AND D1.Date < D2.Date) ) AS [Date_Diff] 
    FROM 
        DataSet AS D1
    WHERE 
        D1.Status ='Uncleared'
) AS SubQ
WHERE 
    [Date_Diff] IS NOT NULL
GROUP BY Person