Thomas Hallgren wrote:
>
> Speaking in generic OO terms, using inheritance, you cannot remove
> attributes that are present in the generalisation. If B inherits A, an
> instance of B is per definition also an instance of A. Thus, you must alwasy
> be able to cast a B into an A. In short, If you don't want the OID, you
> cannot inherit a something that has an OID.
This is not completely true:
struct B
{ void foo();
};
class D : public B
{ private: void foo();
public: void bar();
};
as you can see a D "is a" B but the publich foo() doesn't
appartaint to D, at least an user of D could not use foo()
> Having said that, I think a warning is motivated. The warning should state
> that attributes (columns) present in the generalisation (the parent table)
> cannot be hidden.
Right.
Regards
Gaetano Mendola
