How do I define Foreign Key Optional Relationships in FluentAPI/Data Annotations with the Entity Framework?

Question

I have a (sample) application with the following code:

public class Posts
{

    [Key]
    [Required]
    public int ID { get; set; }

    [Required]
    pub         


        

Answer 1

The reason it wasn't allowing nulls because the following:

public int PollID { get; set; }
public virtual Poll Poll { get; set; }

public int PostID { get; set; }
public virtual Post Post { get; set; }

should have been

public int? PollID { get; set; }
public virtual Poll Poll { get; set; }

public int? PostID { get; set; }
public virtual Post Post { get; set; }