im trying to work through some questions and im not sure how to do the following
Q:Find the hard drive sizes that are equal among two or more PCs.
its q15 on this site
http://www.sql-ex.ru/learn_exercises.php#answer_ref
The database scheme consists of four tables:
Product(maker, model, type)
PC(code, model, speed, ram, hd, cd, price)
Laptop(code, model, speed, ram, hd, screen, price)
Printer(code, model, color, type, price)
any pointers would be appreciated.