EF 4.1 Code First error - The entity type SomeType is not part of the model for the current context

Question

While working with EF code first I get error given below at different times:

The entity type SomeType is not part of the model for the current context.

Answer 1

I got this when my class that inherited from DbContext did not declare the model as a property. For example, I neglected to add a property for FooModel in the code below:

public class MyDBContext : DbContext
{
    public DbSet FooModels{ get; set; }

    // etc. ... 
}