6.2.2 b
6.2.2 b
( SELECT Product.model, price
FROM Product, PC
WHERE maker=‘B’AND Product. model= PC.model )
UNION
( SELECT Product.model, price
FROM Product, Laptop
WHERE maker=‘B’AND Product. model= Laptop.model )
UNION
( SELECT Product.model, price
FROM Product, Printer
WHERE maker=‘B’AND Product. model= Printer.model )
