[odb-users] Object Model based on Interfaces

[Boris Kolpackov]

Hi Christian,

Lichtenberger, Christian <christian.lichtenberger at etm.at> writes:

> #pragma db object polymorphic
> class Base
> {
>   //some base functionality
> }
> 
> class IDerived
> {
>   //define pure virtual functions
> }
> 
> #pragma db object
> class Derived : public Base, public IDerived
> {
>   //implements virtual functions
> }
> 
> How can I archive that following is possible:
>
> main()
> {
>   QSharedPointer<odb::database> db;
>   IDerived derived = new Derived;
>   db->persist<IDerived>(derived);
> }

To persist via IDerived you would have to make it a persistent
object. But ODB does not support multiple inheritance. So the
only way is to simplify this somehow into a single inheritance
chain (e.g., derive Base from IDerived or the other way around).

Boris