DELETE FROM table_name WHERE col_name IN ( SELECT col_name FROM table_name GROUP BY col_name HAVING Count(col_name)>1) DELETE FROM emp WHERE ename IN (SELECT ename FROM emp GROUP BY ename HAVING Count(ename)>1)

Please refer the article Remove duplicate records/data from Sql Server database table http://www.webcodeexpert.com/2013/11/how-to-remove-duplicate-recordsdata.html