SELECT SUM((Antal * Pris) - Rabat) AS [Samlet omsætning]
FROM Salg AS s, Apparat AS a
WHERE s.Apparat_id = a.Apparat_id;

SELECT SUM(Antal) AS [Antal solgte Sony-CD-afspillere]
FROM Fabrikat AS f, Apparat AS a, Type AS t, Salg AS s
WHERE f.Fabrikat_id = a.Fabrikat_id AND
      a.Type_id = t.Type_id AND
      a.Apparat_id = s.Apparat_id AND
      f.Navn = "Sony" AND
      t.Navn = "CD-afspiller";

SELECT s.Salg_id, s.Dato, f.Navn, a.Model, s.Antal
FROM Salg AS s, Apparat AS a, Fabrikat AS f, Type AS t
WHERE f.Fabrikat_id = a.Fabrikat_id AND
      a.Type_id = t.Type_id AND
      a.Apparat_id = s.Apparat_id AND
      t.Navn = "Farvefjernsyn" AND
      s.Dato > "20000229" AND
      s.Dato < "20000401"
ORDER BY Dato ASC;