Oracle query duplicate field

Query a field duplicate data:

　　select org_id from oa_food_yy group by org_id having count(*)>1

Some fields inquiries duplicate data:

　　select org_id,food_id from oa_food_yy group by org_id,food_id having count(*)>1

　　select * from oa_food_yy where (org_id,food_id) in (select org_id,food_id from oa_food_yy group by org_id,food_id having count(*)>1)