I am building this database : http://imageshack.us/photo/my-images/217/diagramg.png/

I have a difficilty Regarding Renting.

Because in this system one can order either DVD Or Game.

Therefore how am i going to link the Game or/and the Dvd to the Rent table ?

Currently it does not work due to the fact that both IDs in the *Type database * have to be inserted. I cannot insert either DVD or Game ID.

Is there a solution how this can work ?