When Database Doesn't Match Conventions or Using OnModelCreating Feature

Using the above new code, we are directing the Entity Framework to use "Name" instead of "StudentName" and "Address" instead of "StudentAddress" whenever the model is created. So, by using this you don't need to update or make any changes in the database. Hope this is clear to you.

Study 2

As in "Study 1", what will happen when "Id" gets unmatched? Let's unmatch it first:

Now, in this case if you run the application you will see the following error:

And the errors are:

One or more validation errors were detected during model generation:

\tSystem.Data.Entity.Edm.EdmEntityType: : EntityType 'CollegeStudents' has no key defined. Define the key for this EntityType.

\tSystem.Data.Entity.Edm.EdmEntitySet: EntityType: EntitySet 'std' is based on type 'CollegeStudents' that has no keys defined.

The clear meaning of this error is, there is a key field in the database and the system is searching for it but unfortunately we modified the name "Id" to "StudentId" so it could not be found. Here is the fix:

Just two modifications, first add the [Key] attribute with "StudentId" property to let the system know "yes this is my new key property" and second added the same thing as we already did in the above Study 1; that is, in the "OnModelCreating()" method.

Note: Entity Framework Code First recognizes the key, by default, by name. Valid names are Id or <YourClassName>Id.

I hope you like this. Thanks.