loading..
   English
20:43

25 . 1

, RAM , RAM. : Maker

RAM. , . , RAM.

. . .

1.17.1

  1. SELECT c.maker
  2. FROM Product c,
  3. (SELECT b.model, MAX(b.speed) speed
  4. FROM PC b
  5. WHERE b.ram IN (SELECT MIN(a.ram)
  6. FROM PC a
  7. )
  8. GROUP BY b.model
  9. ) t
  10. WHERE c.model = t.model AND
  11. EXISTS (SELECT d.model
  12. FROM Printer d, Product e
  13. WHERE d.model = e.model AND
  14. e.maker = c.maker
  15. );

1.

  1. (SELECT b.model, MAX(b.speed) speed
  2. FROM PC b
  3. WHERE b.ram IN (SELECT MIN(a.ram)
  4. FROM PC a
  5. )
  6. GROUP BY b.model
  7. ) t

, . , , . , , ,   (DISTINCT, ).

2.

  1. AND EXISTS (SELECT d.model
  2. FROM Printer d, Product e
  3. WHERE d.model=e.model AND
  4. e.maker = c.maker
  5. )

( 1.2).

3. , , . , , .

1.17.2

  1. SELECT DISTINCT maker
  2. FROM Product
  3. WHERE type = 'printer' AND
  4. maker IN(SELECT maker
  5. FROM Product
  6. WHERE model IN(SELECT model
  7. FROM PC
  8. WHERE speed = (SELECT MAX(speed)
  9. FROM (SELECT speed
  10. FROM PC
  11. WHERE ram=(SELECT MIN(ram)
  12. FROM PC
  13. )
  14. ) AS z4
  15. )
  16. )
  17. );

:

  1. speed = (SELECT MAX(speed)
  2. FROM (SELECT speed
  3. FROM PC
  4. WHERE ram = (SELECT MIN(ram)
  5. FROM PC
  6. )
  7. ) AS z4
  8. )

Bookmark and Share
: 1 2

©SQL-EX,2008 [] [] [ ] [] [Team]
.
Rambler's Top100