Question

My solution consists of two projects:

• a class library project (named as DataAccess) that defines a class (named as MyContext) inheriting from DbContext. As DbContext is defined in EntityFramework.dll assembly, I need to add a reference to this assembly into this class library project. I have no confusion in this mechanism.
• a console application project (named as Tester) that consumes the DataAccess class defined in the class library above. Adding a reference to the assembly of the class library above is understandable. Unfortunately, I cannot compile the solution until I add a reference to EntityFramework.dll into this console application.

Why do we need to add a reference to an assembly, from which a class library project inherits, into a consumer project?
In my mental model, it is enough to only add a reference to DataAccess project assembly into Tester project and the chained references should be done automatically.

Answer 1

Because a lot of the behaviour in MyContext is inherited from the base class in entity framework. If you call those methods (e.g. SaveChanges()) from Tester, the Tester app needs a reference to the class library where the method is defined.

If you would only access methods of MyContext that are defined in your class library, I think you could do without the reference to the base class.