In this three-part series, our SQL author, Scott Whigham, shows you how you can delete duplicate rows in a SQL table using SQL Server 2005/SQL Server 2008. NOTE: This is an advanced series requiring knowledge of correlated subqueries, HAVING/GROUP BY/AGGs, RANK(), ROW_NUMBER(), derived tables, and recursive Common Table Expressions (CTEs). It depends on you already knowing how to find the duplicates and shows you how you can delete these duplicate rows. For reference, the following videos may help prepare you: Design Pattern for Finding Duplicate Data - A Simple Way to Spot Non-Unique Rows (Single Column Test) Design Pattern for Finding Duplicate Data - A Simple Way to Spot Non-Unique Rows Multiple Column Test)Common Table Expressions (CTEs) Part 1 and Part 2Subqueries and Derived Table Tutorial