mysql delet duplicate code example

Example 1: mysql remove duplicates

DELETE FROM table_name WHERE id 
       NOT IN ( SELECT id FROM table_name 
                   GROUP BY field_1, field_2)

Example 2: mysql delete duplicate rows except one

DELETE FROM NAMES
 WHERE id NOT IN (SELECT * 
                    FROM (SELECT MIN(n.id)
                            FROM NAMES n
                        GROUP BY n.name) x)