Understanding code first virtual properties

Question

Hi I am just learning to work with Entity Framework Code First and I can not seem to understand something.I have created three models based on a tutorial:

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Answer 1

It is used to manage lazy loading and change tracking.

EF will generate proxy types on runtime, which are dynamically generated types that inherit from your POCO classes and add all the EF stuff to manage lazy loading / change tracking in the overridden virtual properties.

So virtual is not a "magic keyword" here, virtual is here so your POCOs can be inherited with additional EF-related code at runtime.

Answer 2

When you create a property or method marked with the virtual keyword, you will be allowed to override it in a derived class, thus offering your method a more specialized behaviour depending on the objects you create.

In the case of Entity Framework its also a convention that points out that lazy loading behaviour is used. A question regarding this matter exists here: Entity Framework 4.1 Virtual Properties

Answer 3

Virtual properties are there to allow lazy loading