Yes that is how Entity designer behaves. If you model your structure in the database and use Update model from database it will indeed be modeled as common associations beacuse EF doesn’t know yet that you want to model it as inheritance. You will get this:
You must manually modify this model to use TPT inheritance. First delete both relations. It will also remove navigation properties and you will get this:
Use Inheritance from toolbox (as described on previous screenshot) and draw a line from Film
to Item
and from Game
to Item
. Now you need to finish this model. The current model will not validate because ItemId
is mapped in both parent and child entity. Delete ItemId
from both Film
and Game
entities. You can also make Item entity Abstract and you will get this: