
SELECT MAX([Spales.Longueur]) FROM iris_donnes;

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CREATE FUNCTION obtenirMax (@espece AS varchar(100))
RETURNS float
AS 
BEGIN

    DECLARE @VMax as int
SELECT @VMax = MAX([Spales.Longueur])
FROM iris_donnes
WHERE @espece = Espces

RETURN @VMax

END

----------------

SELECT Espces,[Spales.Longueur],dbo.obtenirMax(Espces) 
FROM iris_donnes