來自同一表EF Core的一對一多個外鍵

Question

堅持為下面的表關系編寫代碼：

public class PersonModel
{
    public int ID { get; set; }
    public string Name{ get; set; }
    public string Address{ get; set; }
    public DateTime? DateofBirth{ get; set; }
    public GenderEnum Gender{ get; set; }

    public PersonDetailModel PersonDetail { get; set; }
    public PersonDetailModel PersonDetailforMate { get; set; }
}

public class PersonDetailModel
{
    public int ID { get; set; }
    public int PersonID { get; set; }
    public int? MateID { get; set; }
    public string PhoneNumber{ get; set; }
    public string OfficeAddress{ get; set; }
    public MarriageStatusEnum MarriageStatus{ get; set; }

    public PersonModel Person { get; set; }
    public PersonModel PersonforMate { get; set; }
}

我使用 Fluent API：

modelBuilder.Entity<PersonModel>()
            .HasOne(d => d.PersonDetailModel)
            .WithOne(p => p.PersonModel)
            .HasForeignKey<PersonDetailModel>(d => d.PersonID);

modelBuilder.Entity<PersonDetailModel>()
            .HasOne(d => d.PersonModel)
            .WithOne(p => p.PersonDetailModel)
            .HasForeignKey<PersonDetailModel>(d => d.MateID);

當我構建時，它收到錯誤

Cannot create a relationship between 'PersonModel.PersonDetailforMate' and 'PersonDetailModel.Person', because there already is a relationship between 'PersonModel.PersonDetail' and 'PersonDetailModel.Person'. Navigation properties can only participate in a single relationship.

類似問題有幾個參考：

• 多個外鍵首先指向實體框架 4.1 代碼中的同一個表
• 2 外鍵作為主鍵使用 EF Core 2.0 Code First
• 同一主鍵上的EF多個外鍵關系

但那些是一對多的關系。

*對不起，我的英語不好

Answer 1

我在我的項目中遇到了類似的情況，這就是我最終要做的：

public class PersonModel
{
    public int ID { get; set; }
    public string Name{ get; set; }
    public string Address{ get; set; }
    public DateTime? DateofBirth{ get; set; }
    public GenderEnum Gender{ get; set; }

    public int PersonID { get; set; }
    [ForeignKey("PersonID ")]
    public PersonDetailModel PersonDetail { get; set; }

    public int? MateID { get; set; }
    [ForeignKey("MateID")]
    public PersonDetailModel PersonDetailforMate { get; set; }
}

public class PersonDetailModel
{
    public int ID { get; set; }
    public string PhoneNumber{ get; set; }
    public string OfficeAddress{ get; set; }
    public MarriageStatusEnum MarriageStatus{ get; set; }
}

所以PersonModel會有兩個PersonDetailModel外鍵。 我使用ForeignKey屬性來明確告訴 EF 哪個外鍵屬於哪個關系 - 如果您使用Foreignkey屬性，則不需要 Fluent API 配置...

上面的代碼將在數據庫中為您構建一個PersonModel表，其中PersonId和MateId列作為外鍵。