Group by:difficoltoso

SELECT C1.Classe, C1.ContMAD1, C2.ContRitPart1, C3.ContRitArrivo1
FROM ((
    SELECT ContMAD AS Classe, COUNT(ContMAD) AS ContMAD1
    FROM Conteggi
    GROUP BY ContMAD
) AS C1
INNER JOIN (
    SELECT ContRitPart AS Classe, COUNT(ContRitPart) AS ContRitPart1
    FROM Conteggi
    GROUP BY ContRitPart
) AS C2
ON C1.Classe = C2.Classe)
INNER JOIN (
    SELECT ContRitArrivo AS Classe, COUNT(ContRitArrivo) AS ContRitArrivo1
    FROM Conteggi
    GROUP BY ContRitArrivo
) AS C3
ON C1.Classe = C3.Classe;