Partition Data to Find the Most Recent Record in SQL Server 2005/2008

A user had a requirement where he wanted to find out the most recent OrderDate in a table, grouped by Customers. The data contained information like OrderDate, Price and ProductId purchased by Customers. In order to find the most recently placed order for each Customer, you can partition the data as shown below:

Sample Data

DECLARE @TT table(CustID int, ProductID int, OrderDate datetime, Spending decimal(10,3))

INSERT @TT 

SELECT 1133, 100 , '04/28/2009', 5.03 UNION ALL

SELECT 1431, 103 , '04/28/2009', 19.02 UNION ALL

SELECT 1431, 105 , '04/28/2009', 15.00 UNION ALL

SELECT 1133, 100 , '04/29/2009', 13.40 UNION ALL

SELECT 1142, 105 , '04/29/2008', 14.60 UNION ALL

SELECT 1142, 103 , '04/29/2008', 11.70 UNION ALL

SELECT 1133, 100 , '04/29/2008', 18.60 

Query

-- Find Most Recent Order for each Customer

SELECT Custid, Spending, OrderDate FROM

(

SELECT CustID, Spending, OrderDate, ROW_NUMBER() OVER

(PARTITION by CustID ORDER BY OrderDate) AS custGrp

FROM @TT

) AS Tot

WHERE custGrp = 1

Results

Custid    Spending    OrderDate

1133    18.600    2008-04-29 00:00:00.000

1142    14.600    2008-04-29 00:00:00.000

1431    19.020    2009-04-28 00:00:00.000

About The Author

Suprotim Agarwal, MCSD, MCAD, MCDBA, MCSE, is the founder of DotNetCurry, DNC Magazine for Developers, SQLServerCurry and DevCurry. He has also authored a couple of books 51 Recipes using jQuery with ASP.NET Controls and a new one recently at The Absolutely Awesome jQuery CookBook.

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