Configurable product has duplicate simple product with same attribute or not check

Import configurable csv to a mysql database table then try to use bellow sql query which give you the duplicate simple product with same attribute values.

SELECT `sku`,count(*) as C FROM `table_1` Group BY `orientatie`,`material`,`papier`,`paginas`,`paper_type_cover`,`veredeling_omslag`,`levertijd`,`aantal` Having COUNT(*) > 1