Delete Duplicate Rows

Posted on April 29, 2013October 26, 2015 By David Kittell

CREATE TABLE DuplicateRcordTable (Col1 INT, Col2 INT)
INSERT INTO DuplicateRcordTable
SELECT 1, 1
UNION ALL
SELECT 1, 1 --duplicate
UNION ALL
SELECT 1, 1 --duplicate
UNION ALL
SELECT 1, 2
UNION ALL
SELECT 1, 2 --duplicate
UNION ALL
SELECT 1, 3
UNION ALL
SELECT 1, 4
GO

SELECT *
FROM DuplicateRcordTable
GO

WITH CTE (COl1,Col2, DuplicateCount)
AS
(
SELECT COl1,Col2,
ROW_NUMBER() OVER(PARTITION BY COl1,Col2 ORDER BY Col1) AS DuplicateCount
FROM DuplicateRcordTable
)
DELETE
FROM CTE
WHERE DuplicateCount > 1
GO

SELECT *
FROM DuplicateRcordTable
GO

Reference: http://blog.sqlauthority.com/2009/06/23/sql-server-2005-2008-delete-duplicate-rows/

Originally Posted on April 29, 2013
Last Updated on October 26, 2015

All information on this site is shared with the intention to help. Before any source code or program is ran on a production (non-development) system it is suggested you test it and fully understand what it is doing not just what it appears it is doing. I accept no responsibility for any damage you may do with this code.

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