EF core code first configuring relationships

Question

I'm trying to set up a competetion.

I have following models:

public class Player
{
    [Required]
    public Guid PlayerId { get; set; }

    [Required]
    public string Firstname { get; set; }

    [Required]
    public string Lastname { get; set; }
}

public class Team
{
    [Required]
    public Guid TeamId { get; set; }

    [Required]
    public string TeamName { get; set; }

    [Required]
    [MaxLength(2)]
    [ForeignKey("TeamPlayerFK")]
    public List<Player> PlayersList { get; set; }
}

public class Match
{
    [Required]
    public Guid MatchId { get; set; }

    [ForeignKey("MatchTeamFK")]
    public Team Team { get; set; }

    [ForeignKey("MatchPlayerFK")]
    public Player Player { get; set; }

    [Required]
    public DateTime MatchDateTime { get; set; }

    public int? Points { get; set; }
}

Having this setup makes a player only able to be in one team. It should be able to join multiple teams. Could someone help me in the right direction?

The player should have property TeamId. Better you draw the relationship between tables on paper and then think — Vivek Nuna, Apr 18 '18 at 10:06

score 2 · Answer 1 · answered Apr 18 '18 at 11:23

Here's the answer I found with help of @GertArnold:

public class Player
{
    [Required]
    public Guid PlayerId { get; set; }

    [Required]
    public string Firstname { get; set; }

    [Required]
    public string Lastname { get; set; }

    public virtual ICollection<TeamPlayer> TeamPlayers { get; set; }

    public virtual ICollection<Match> Matches { get; set; }
}
public class Team
{
    [Required]
    public Guid TeamId { get; set; }

    [Required]
    public string TeamName { get; set; }

    [Required]
    public virtual ICollection<TeamPlayer> TeamPlayers { get; set; }
}
public class TeamPlayer
{
    public Guid TeamPlayerId { get; set; }

    public Guid TeamId { get; set; }
    public Team Team { get; set; }

    public Guid PlayerId { get; set; }
    public Player Player { get; set; }
}
public class Match
{
    [Required]
    public Guid MatchId { get; set; }

    public Guid TeamId { get; set; }
    public Team Team { get; set; }

    public Guid PlayerId { get; set; }
    public Player Player { get; set; }

    [Required]
    public DateTime MatchDateTime { get; set; }

    public int? Points { get; set; }
}

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<TeamPlayer>()
            .HasOne(tp => tp.Team)
            .WithMany(t => t.TeamPlayers)
            .HasForeignKey(tp => tp.TeamId);

        modelBuilder.Entity<TeamPlayer>()
            .HasOne(tp => tp.Player)
            .WithMany(p => p.TeamPlayers)
            .HasForeignKey(tp => tp.PlayerId);

        base.OnModelCreating(modelBuilder);
    }

EF core code first configuring relationships

1 Answers1