Yurttas/PL/DBL/postgres/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
 9SELECT current_schema();
10SET search_path to "pc";
11
12(SELECT P.maker
13 FROM Product P, Laptop L
14 WHERE P.model=L.model)
15MINUS
16(SELECT P.maker
17 FROM Product P, PC
18 WHERE P.model=PC.model);