Yurttas/PL/DBL/mssql/F/01/PC/q07.sql

 1/*
 2REM
 3REM q07.sql
 4REM
 5REM Find the manufacturer(s) of the computer(PC or laptop)
 6REM with the highest available speed.
 7REM
 8*/
 9
10CREATE VIEW ProdSpeed(model, speed)
11  AS (SELECT model, speed
12      FROM PC
13      WHERE speed IN (SELECT MAX(speed)
14                      FROM  PC))
15     UNION
16     (SELECT model, speed
17      FROM Laptop
18      WHERE speed IN (SELECT MAX(speed)
19                      FROM  Laptop));
20
21SELECT P.maker, S.speed
22FROM Product P, ProdSpeed S
23WHERE P.model=S.model
24  AND S.speed IN (SELECT MAX(speed)
25                  FROM ProdSpeed);