Yurttas/PL/DBL/mssql/F/01/PC/q05.sql

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