Define Entity Framework relationships using foreign keys only by FluentAPI

Question

Is any way of defining Entity Framework relations using foreign keys only (no virtual properties of reference type) with FluentAPI (data models should not be changed)?

CardDataModel

public class CardDataModel
{
    public int CardId { get; set; }

}

CheckItemDataModel

public class CheckItemDataModel
{
    public int CheckItemId { get; set; }
    public int CardId { get; set; }
}

Answer 1

Yes, it's possible in EF Core. It wasn't in EF6 and below, but now EF Core provides parameterless overloads of HasMany / HasOne which allow configuring such relationship:

modelBuilder.Entity<CardDataModel>()
    .HasMany<CheckItemDataModel>() // <-- note this
    .WithOne()
    .HasForeignKey(e => e.CardId);