我们无法以一流的方式对无向图进行建模。链接表必须有一个FromStation，ToStation，如果你总是可以双向，你需要两个条目。所以试着

public class Station
{

    [Key]
    public int StationId { get; set; }

    [Required]
    [Column(TypeName = "VARCHAR")]
    [StringLength(100)]
    public string TerminalName { get; set; }

    [Required]
    [Column(TypeName = "VARCHAR")]
    [StringLength(100)]
    public string City { get; set; }

    [Required]
    [Column(TypeName = "VARCHAR")]
    [StringLength(100)]
    public string Province { get; set; }

    public ICollection<Station> IncomingDestinations { get; set; }
    public ICollection<Station> OutgoingDestinations { get; set; }
}

首先你需要这个额外的类

public class Mapped_Stations
{
    public int OriginId { get; set; }

    public int DestinationId { get; set; }

    public Station Origin { get; set; }

    public Station Destination { get; set; }
}

接下来在你的电台类中添加两个列表

public class Station
{
    [Key]
    public int StationId { get; set; }

    [Required]
    [Column(TypeName = "VARCHAR")]
    [StringLength(100)]
    public string TerminalName { get; set; }

    [Required]
    [Column(TypeName = "VARCHAR")]
    [StringLength(100)]
    public string City { get; set; }

    [Required]
    [Column(TypeName = "VARCHAR")]
    [StringLength(100)]
    public string Province { get; set; }

    //Add This Lists
    public List<Mapped_Stations> Origins { get; set; }
    public List<Mapped_Stations> Destinations { get; set; }
}

然后创建一个Map文件夹，并在该文件夹中添加类，并使用IEntityTypeConfiguration

public class Mapped_SatationsMap : IEntityTypeConfiguration<Mapped_Stations>
{
    public void Configure(EntityTypeBuilder<Mapped_Stations> builder)
    {
        builder.HasKey(t => new { t.OriginId, t.DestinationId });
        builder
            .HasOne(t => t.Origin)
            .WithMany(p => p.Origins)
            .HasForeignKey(f => f.OriginId);
        builder
            .HasOne(t => t.Destination)
            .WithMany(p => p.Destinations)
            .HasForeignKey(f => f.DestinationId).OnDelete(DeleteBehavior.Restrict);
    }
}

最后配置Db

public class Db:DbContext
{
    public Db() : base() { }

    protected override void OnConfiguring(DbContextOptionsBuilder options)
    {
        options.UseSqlServer(@"Server=(local);Database=StackOverFlow;Trusted_Connection=True");
    }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.ApplyConfiguration(new Mapped_SatationsMap());
    }

    DbSet<Mapped_Stations> Mapped_Stations { get; set; }
    DbSet<Station> stations { get; set; }
}