如何在一个表中创建两个指向某个表中同一列的外键？

Question

我有一个我要实现的数据库设计，这很困难，并出现错误“有多个ForeignKeyAttributes指向相同的属性集”

我们有一个机场和一个航班，一个航班有一个外键指向要飞行的机场，另一个有外键指向该航班要去的机场。

但两个机场都在同一张表中。 Flight表中有两个外键指向Airport表中的同一列

机场舱

{
public class Airport
{
    [Key]
    public int Id { get; set; }

    [ForeignKey(nameof(Flight.ToAirportId))]
    public ICollection<Flight> ComingFlightsId { get; set; }

    [ForeignKey(nameof(Flight.FromAirportId))]
    public ICollection<Flight> GoingFlightsId { get; set; }
}}

飞行舱

{
public class Flight
{
    [Key]
    public int Id { get; set; }

    [ForeignKey(nameof(FromAirportId))]
    public Airport FromAirport { get; set; }
    public int FromAirportId { get; set; }

    [ForeignKey(nameof(ToAirportId))]
    public Airport ToAirport { get; set; }
    public int ToAirportId { get; set; }
}}

Answer 1

只需使用这个：

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

  [InverseProperty("FromAirport")]
  public ICollection<Flight> ComingFlights { get; set; }

  [InverseProperty("ToAirport")]
  public ICollection<Flight> GoingFlights { get; set; }
}


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

   public int FromAirportId { get; set; }

   public int ToAirportId { get; set; }

   [ForeignKey(nameof(FromAirportId))]
   [InverseProperty("ComingFlights")]
   public Airport FromAirport { get; set; }


   [ForeignKey(nameof(ToAirportId))]
   [InverseProperty("GoingFlights")]
   public Airport ToAirport { get; set; }    
 }

Answer 2

我找到了问题的答案。 逆属性

将此注释添加到ICollection

这就是我的机场班级的样子

{
public class Airport
{
    [Key]
    public int Id { get; set; }
    public string Locatoin { get; set; }


    [InverseProperty(nameof(Flight.ToAirportId))]
    public ICollection<Flight> ComingFlightsId { get; set; }

    [InverseProperty(nameof(Flight.FromAirportId))]
    public ICollection<Flight> GoingFlightsId { get; set; }
}}

Answer 3

尝试在public ICollection<Flight> ComingFlightsId { get; set; }上使用virtual修饰符public ICollection<Flight> ComingFlightsId { get; set; } public ICollection<Flight> ComingFlightsId { get; set; } public ICollection<Flight> ComingFlightsId { get; set; }和public ICollection<Flight> GoingFlightsId { get; set; } public ICollection<Flight> GoingFlightsId { get; set; } public ICollection<Flight> GoingFlightsId { get; set; }然后从其中删除ForeignKey属性