Using Effort (EF Testing Tool) with Computed Column

I have a number of integration tests which access the DB directly - create test prerequisite objects - performs the tests and then cleans up afterwards - however I wonted to try out the same approach in-memory.

I have just used Effort in my project and it works very easily. However I've hit a problem that I have been trying - but unable to solve.

One of the tables that I need filled up with dummy data - as a test prerequisite - contains a computed column (nvarchar, not null). For the scope of the test I really don't care about that column's value - but even if I try to insert dummy data, my data is ignored and then I get hit with an error:

"Column 'x' cannot be null. Error code: GenericError"

In my tests I am using the same edmx file as is used by the actual code. This prevents me from constantly updating the edmx copy.

Is there a way in which I can force the test to update the edmx (at runtime) so that column is a nullable non-computed column? [overriding OnModelCreating] or is there way to insert a default value (anything goes for this column) to stop this error? [overriding SaveChanges]

I have currently tried the following:

• Attaching the objects using .Attach() instead of .Add()
• Setting the EntityState to Unchanged after adding
• Forcing the value through Entry.OriginalValues [this values since entity is in Added state]

Edit:

I have tried overriding the OnModelCreating method, but to no avail since this is DB-First.

modelBuilder.Entity<Entity_Name>().Property(p => p.x).IsOptional().HasDatabaseGeneratedOption(System.ComponentModel.DataAnnotations.Schema.DatabaseGeneratedOption.None);