mysql dapatkan baris duplikat terbaru

SELECT
   t1.primary_id,
   t1.duplicate_id,
   t1.data1,
   t1.data2
FROM
   table_name t1
LEFT JOIN table_name t2
	ON (t1.duplicate_id = t2.duplicate_id AND t1.primary_id < t2.primary_id) 
WHERE
	t2.primary_id IS NULL

MatrixZA