Yurttas/PL/DBL/oracle/F/01/PC/q05.sql
1REM
2REM q05.sql
3REM
4REM Find those manufacturers that sell Laptops, but not PC's.
5REM
6
7(SELECT P.maker
8 FROM Product P, Laptop L
9 WHERE P.model=L.model)
10MINUS
11(SELECT P.maker
12 FROM Product P, PC
13 WHERE P.model=PC.model);