对每项物品，找出最贵价格的物品的经销商
SELECT name, dealer, price FROM shop s1 WHERE price=(SELECT MAX(s2.price) FROM shop s2 WHERE s1.name = s2.name)
对每项物品，找出最贵价格的物品的经销商
SELECT name, dealer, price FROM shop s1 WHERE price=(SELECT MAX(s2.price) FROM shop s2 WHERE s1.name = s2.name)