Посмотрите на что-то вроде этого (полный пример)
DECLARE @Store_Sales TABLE(
Store INT,
Date DATETIME,
Sales FLOAT
)
INSERT INTO @Store_Sales SELECT 1,'23 Apr 2010',10000
INSERT INTO @Store_Sales SELECT 2,'23 Apr 2010',11000
INSERT INTO @Store_Sales SELECT 1,'22 Apr 2010',10000
INSERT INTO @Store_Sales SELECT 2,'22 Apr 2010',10500
INSERT INTO @Store_Sales SELECT 1,'21 Apr 2010',10000
INSERT INTO @Store_Sales SELECT 2,'21 Apr 2010',10550
SELECT ss.Store,
MIN(ss.Date) StartDate,
MAX(ssNext.Date) EndDate,
ss.Sales
FROM @Store_Sales ss INNER JOIN
@Store_Sales ssNext ON ss.Store = ssNext.Store
AND ss.Date + 1 = ssNext.Date
AND ss.Sales = ssNext.Sales
GROUP BY ss.Store,
ss.Sales