Common Table Expressions (CTE) in SQL Server 2005 and Up
Thanks to the team at TechRepublic.com and BOL, I have used CTEs to delete duplicates with ease in SQL Server 2005 and higher. Learn more about CTEs at TechRepublic. Here meat of the article a sample:
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;WITH SalesCTE(Product, SaleDate, SalePrice, Ranking) AS (SELECT Product , SaleDate , SalePrice , Ranking = DENSE_RANK() OVER(PARTITION BY Product, SaleDate, SalePrice ORDER BY NEWID() ASC) FROM SalesHistory ) DELETE FROM SalesCTE WHERE Ranking > 1 |
Very easy and handy! Check out BOL for all kinds of information regarding Dense_Rank(), NEW_ID(), and PARTITION BY. While you’re there, check out RANK(), NTILE(), and ROW_NUMBER() I’m sure there is a combination that will help your current situation. Please note, this is for SQL Server 2005 and above. RudyRudy Rodarte is a SQL Server Database professional based in Austin, TX. Over his … Continue reading Common Table Expressions (CTE) in SQL Server 2005 and Up