CREATE TRIGGER VerifierStock
ON commandes
FOR  INSERT
AS
BEGIN
    declare @id_stock int,@quantite_commande int
    select @id_stock = id_stock FROM INSERTED
    select @quantite_commande = quantite_commande FROM INSERTED

    IF (SELECT quantite_stocke FROM stock WHERE id_stock = @id_stock) < @quantite_commande
        BEGIN
            RAISERROR('La quantité demandé n est pas disponible pour le stock',16,10)
            Rollback transaction
        END

END