Question

I am working on a simple MVC application using Entity Framework to track the scores of a Badminton league. I have the following two classes:

public class Game
{
    public int Id { get; set; }
    public Player Player1 { get; set; }
    public Player Player2 { get; set; }
    public int Player1Score { get; set; }
    public int Player2Score { get; set; }
}

and

public class Player
{
    public int Id { get; set; }
    public string FirstName { get; set; }
    public string Surname { get; set; }
    public List<Game> Games { get; set; }
}

The problem I have is when I have an instance of a player the Games property is returning an empty list. When I request my list of players I use the following:-

var players = badmintonDB.Players.Include("Games").ToList();

From a search on SO I have attempted to override OnModelCreating. I have tried the following with and without the Map(). This creates another table in my database but it doesn’t contain any records.

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        modelBuilder.Entity<Player>().HasMany(p => p.Games).WithMany()
            .Map(m =>
            {
                m.ToTable("PlayerGames");
                m.MapLeftKey("Player_Id");
                m.MapRightKey("Game_Id");
            });

        base.OnModelCreating(modelBuilder);

    }

I cannot see where I am going wrong, whether I need to rethink the design of my POCO’s or if I have the syntax wrong when overriding OnModelCreating.

Any help would be appreciated.

Answer 1

I’m not sure if that design can work the way you want it to. What if you made a new “Score” entity to tie players to games like so:

public class Game
{
    public int Id { get; set; }
    public virtual ICollection<Score> Scores { get; set; }
}

public class Player
{
    public int Id { get; set; }
    public string FirstName { get; set; }
    public string Surname { get; set; }
    public virtual ICollection<Score> Scores { get; set; }
}

public class Score
{
    public int ScoreId { get; set; }
    public virtual  Player Player { get; set; }
    public virtual Game Game { get; set; }
    public int Score { get; set; }
}