Is customer ID Supposed to be the same across all customers?

CREATE TABLE #CustomerPurchase(

[PurchaseDate] [datetime] NOT NULL,

[CustomerID] [int] NOT NULL,

[CustomerName] [varchar](25) NULL,

[PurchaseDetails][varchar](500)NULL

) ON [PRIMARY]

GO

--Insert some sample data into the sample table

GO

INSERT INTO #CustomerPurchase ( PurchaseDate, CustomerID, CustomerName, PurchaseDetails)

SELECT '2012-06-01 00:00:00.000',1001,'Wilson Menthis','Purchased Item 6AB2'

UNION ALL

SELECT '2012-06-01 00:00:00.000',1001,'Wilson Menthis','Loyalty Customers'

UNION ALL

SELECT '2012-06-01 00:00:00.000',1001,'Wilson Menthis','20%DiscountReceived on Office Furniture'

UNION ALL

SELECT '2012-06-01 00:00:00.000',1001,'John Gray','Purchased $250 worth of Miscellaneous Products'

UNION ALL

SELECT '2012-06-01 00:00:00.000',1001,'Kevin Chang','Loyalty Customers'

UNION ALL

SELECT '2012-06-01 00:00:00.000',1001,'Kevin Chang','Returned OfficeDesk due to defect on the surface'

GO

--Select some data from the table for the particular day

SELECT *

FROM #CustomerPurchase cp

INNER JOIN (SELECT *

FROM #CustomerPurchase

WHERE PurchaseDate = '2012-06-01 00:00:00.000'

AND PurchaseDetails = 'Loyalty Customers') AS lc

ON cp.CustomerName = lc.CustomerName

-- Remove this if you don't care what date the customers purchases were for, or Add < if you only want purchases before this date

AND cp.PurchaseDate = lc.PurchaseDate