Yurttas/PL/DBL/oracle/F/01/PC/q13.sql

 1REM
 2REM q13.sql
 3REM
 4REM Delete all Laptops made by a manufacturer that doesn't make
 5REM printers.
 6REM
 7
 8DELETE FROM Product
 9WHERE type='laptop'
10  AND maker NOT IN (SELECT maker
11		    FROM Product
12		    WHERE type='printer');
13
14DELETE FROM Laptop
15WHERE model NOT IN (SELECT model
16                    FROM Product);