select pro_list.product_id, pro_list.product_name, market_id, store_id from( (select product_id, product_name from test.hamstermarket union select product_id, product_name from test.hamsterstore) as pro_list) left join test.hamstermarket on test.hamstermarket.product_id = pro_list.product_id left join test.hamsterstore on test.hamsterstore.product_id = pro_list.product_id order by pro_list.product_id;