Yurttas/PL/DBL/oracle/F/01/PC/q03.sql

 1REM
 2REM q03.sql
 3REM
 4REM Find the model number and price of all products
 5REM (of any type) made by manufacturer 'B'.
 6REM
 7
 8(SELECT PC.model, price
 9 FROM Product P, PC
10 WHERE maker='B'
11   AND P.model=PC.model )
12UNION
13(SELECT L.model, L.price
14 FROM Product P, Laptop L
15 WHERE maker='B'
16   AND P.model=L.model)
17UNION
18(SELECT R.model, R.price
19 FROM Product P, Printer R
20 WHERE P.maker='B'
21   AND P.model=R.model);