One example of foreign key model, using code first approach:

  

public class MyMaster
{
	public int Id { get; set; }
	public string Username { get; set; }

	public virtual ICollection MyDetails { get; set; }
}

public class MyDetail
{
	public int Id { get; set; }

	[ForeignKey("MyMaster")]
	public int masterId { get; set; }

	public virtual MyMaster MyMaster { get; set; }
}

and another version of same thing:

public class MyMaster
{
	public int MyMasterId { get; set; }
	public string Username { get; set; }

}

public class MyDetail
{
	public int MyDetailId { get; set; }

	[ForeignKey("MyMasterId")]
	public int masterId { get; set; }

	public virtual MyMaster MyMasterId { get; set; }
}