I have checked the whole site and googled on the net but was unable to find a simple solution to this problem.
I have a datatable which has about 20 columns and 10K
Use a query instead of functions:
DELETE FROM table1 AS tb1 INNER JOIN (SELECT id, COUNT(id) AS cntr FROM table1 GROUP BY id) AS tb2 ON tb1.id = tb2.id WHERE tb2.cntr > 1