c# - EF Core 不完全引用模型之间

Question

我在项目中使用的实体类:

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

    public int FirstTeamId { get; set; }
    public Team FirstTeam { get; set; }
    public int SecondTeamId { get; set; }
    public Team SecondTeam { get; set; }

    public Stadium Stadium { get; set; }
    public DateTime Date { get; set; }

    public GameStatus Result { get; set; }

    public Game(DateTime date , GameStatus result )
    {
        Date = date;
        Result = result;
    }
}

public class Player
{
    public int Id { get; set; }
    public string Name { get; set; }
    public string Surname { get; set; }
    public DateTime Birthday { get; set; }
    public PlayerStatus Status { get; set; }
    public PlayerHealthStatus HealthStatus { get; set; }
    public int Salary { get; set; }
    public int TeamId { get; set; }
    public Team Team { get; set; }

    public Player(string name , string surname, DateTime birthday, PlayerStatus status, PlayerHealthStatus healthStatus, int salary)
    {
        Name = name;
        Surname = surname;
        Birthday = birthday;
        Status = status;
        HealthStatus = healthStatus;
        Salary = salary;
    }

}

public class Stadium
{
    public int Id { get; set; }
    public string Name { get; set; }
    public int Capacity { get; set; }
    public int PriceForPlace { get; set; }

    public Stadium(string name, int capacity, int priceForPlace)
    {
        Name = name;
        Capacity = capacity;
        PriceForPlace = priceForPlace;
    }
}

public class Team
{
    public int Id { get; set; }
    public string Name { get; set; }
    public List<Player> Players { get; set; }

    public List<Game> Games { get; set; }

    public Team(string name)
    {
        Name = name;
    }

    public Team(string name, List<Player> players) : this(name)
    {
        Players = players;

    }
}

我的 EF Core 上下文类:

public class ApplicationContext : DbContext
{
    public DbSet<Player> Players { get; set; }
    public DbSet<Game> Games { get; set; }
    public DbSet<Team> Teams { get; set; }
    public DbSet<Stadium> Stadiums { get; set; }

    public ApplicationContext()
    {
        Database.EnsureCreated();
    }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        optionsBuilder.UseSqlServer("Server=best-komp;Database=FootballApplicationDataBase;Trusted_Connection=True;");
    }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<Player>()
            .HasOne(p => p.Team)
            .WithMany(t => t.Players)
            .HasForeignKey(p => p.TeamId).OnDelete(DeleteBehavior.NoAction)
            .HasPrincipalKey(t => t.Id);
        modelBuilder.Entity<Team>()
            .HasMany(t => t.Players)
            .WithOne(p => p.Team)
            .HasForeignKey(p => p.Id).OnDelete(DeleteBehavior.NoAction)
            .HasPrincipalKey(t => t.Id);
        modelBuilder.Entity<Game>()
            .HasOne(g => g.HomeTeam)
            .WithMany(t => t.HomeGames)
            .HasForeignKey(t => t.HomeTeamId)
            .HasPrincipalKey(t => t.Id);
        modelBuilder.Entity<Game>()
            .HasOne(g => g.AwayTeam)
            .WithMany(t => t.AwayGames)
            .HasForeignKey(t => t.AwayTeamId).OnDelete(DeleteBehavior.NoAction)
            .HasPrincipalKey(t => t.Id);
    }
}

但是当我尝试调用我的上下文类时，比如

var db = new ApplicationContext();

我可以看到我的团队和玩家类不相互引用。
所有其他类都有引用团队，例如玩家有团队，游戏有团队。但是我的团队类(class)没有引用任何类(class)，他们有 NULL 而不是引用。
问题是什么？

Answer 1

您的团队配置不正确。外键应该是 TeamId 而不是 Id。由于 Players 实体上的 FK 是 TeamId。

modelBuilder.Entity<Team>()
        .HasMany(t => t.Players)
        .WithOne(p => p.Team)
        .HasForeignKey(p => p.TeamId).OnDelete(DeleteBehavior.NoAction)
        .HasPrincipalKey(t => t.Id);