EF Core Net 5 - Code First - 与同一实体的多种关系

Question

我正在尝试设置两个实体之间的多重关系，如下所示：

一个公司有多个地址。
一家公司有一个默认地址。
一家公司有一个默认账单地址。
一家公司有一个默认收货地址。

public abstract class BaseAddress : AbstractValidatableEntity
{
    public AddressType Type { get; set; }
    public AddressStatus Status { get; set; }
    public Country Country { get; set; }
    public string Address1 { get; set; }
    public string Address2 { get; set; }
    public string Address3 { get; set; }
    public string Address4 { get; set; }
    public string City { get; set; }
    public string State { get; set; }
    public string ZipCode { get; set; }
}

public class CompanyAddress : BaseAddress
{
    public Guid CompanyId { get; set; }
    public Company Company { get; set; }
}

public class Company : AbstractValidatableEntity
{
    public string Name { get; set; }
    public List<User> Users { get; set; }
    public Guid OwnerId { get; set; }
    public User Owner { get; set; }
    public List<CompanyAddress> Addresses { get; set; }
    public CompanyAddress DefaultAddress { get; set; }
    public CompanyAddress DefaultBillingAddress { get; set; }
    public CompanyAddress DefaultDeliveryAddress { get; set; }
}

public class CompanyConfiguration : AbstractEntityConfiguration<Company>
{
    public override void Configure(EntityTypeBuilder<Company> builder)
    {
        base.Configure(builder);
        // Table name
        builder
            .ToTable("Companies");
        // Columns
        builder
            .Property(s => s.Name)
            .IsRequired(true)
            .HasMaxLength(255);
        // Relationships
        builder
            .HasMany(s => s.Users)
            .WithOne(u => u.Company)
            .HasForeignKey(u => u.CompanyId)
            .IsRequired(false)
            .HasConstraintName("FK_COMPANY_USERS");
        builder
            .HasMany(s => s.Addresses)
            .WithOne(a => a.Company)
            .HasForeignKey(a => a.CompanyId)
            .IsRequired()
            .HasConstraintName("FK_COMPANY_ADDRESSES")
            .OnDelete(DeleteBehavior.Cascade);
        builder
            .HasOne(s => s.DefaultAddress)
            .WithOne()
            .HasForeignKey<CompanyAddress>(da => da.CompanyId)
            .IsRequired(false)
            .HasConstraintName("FK_COMPANY_DEFAULT_ADDRESS")
            .OnDelete(DeleteBehavior.Restrict);
        builder
            .HasOne(s => s.DefaultBillingAddress)
            .WithOne()
            .HasForeignKey<CompanyAddress>(da => da.CompanyId)
            .IsRequired(false)
            .HasConstraintName("FK_COMPANY_DEFAULT_BILLING_ADDRESS")
            .OnDelete(DeleteBehavior.Restrict);
        builder
            .HasOne(s => s.DefaultDeliveryAddress)
            .WithOne()
            .HasForeignKey<CompanyAddress>(da => da.CompanyId)
            .HasConstraintName("FK_COMPANY_DEFAULT_DELIVERY_ADDRESS");
        // Indexes
        builder
            .HasIndex(s => s.Name)
            .HasDatabaseName("IX_COMPANY_NAME");
    }
}

但是在创建数据库时出现以下错误：

System.InvalidOperationException: 'Unable to determine the relationship represented by navigation 'Company.Addresses' of type 'List'. Either manually configure the relationship, or ignore this property using the '[NotMapped]' attribute or by using 'EntityTypeBuilder.Ignore' in 'OnModelCreating'.'

请注意，我试图实现 1 个多对一关系和 3 个一对一关系 table，这与我在此处搜索的所有其他问题不同。

我读过多个类似的问题，但它们都有以下情况：
一个公司有多个地址。
一家公司有一个默认地址。

如果我删除代码中的第二个和第三个一对一关系，它将完美运行。我不确定在代码方面该怎么做。

我知道我可以在数据库方面做到这一点。拥有一个 CompanyAdresses table 并在 Company table 上拥有这些属性：DefaultAddressId、DefaultBillingAddressId、DefaultDeliveryAddressId。

在此先感谢大家。

Answer 1

对于具有不同语义的 Company 和 Address 之间的每个关系，您应该有一个 ForeignKey。例如：


public class Company : AbstractValidatableEntity
{
    public string Name { get; set; }
    public List<User> Users { get; set; }
    public Guid OwnerId { get; set; }
    public User Owner { get; set; }
    public List<CompanyAddress> Addresses { get; set; }
    public CompanyAddress DefaultAddress { get; set; }
    public CompanyAddress DefaultBillingAddress { get; set; }
    public CompanyAddress DefaultDeliveryAddress { get; set; }


    public Guid DefaultAddressId { get; set; }
    public Guid DefaultBillingAddressId { get; set; }
    public Guid DefaultDeliveryAddressId { get; set; }
}

然后，用自己的 FK 配置每个关系。

...
builder
            .HasOne(s => s.DefaultAddress)
            .WithOne()
            .HasForeignKey<Company>(da => da.DefaultAddressId)
            .IsRequired(false)
            .HasConstraintName("FK_COMPANY_DEFAULT_ADDRESS")
            .OnDelete(DeleteBehavior.Restrict);
        builder
            .HasOne(s => s.DefaultBillingAddress)
            .WithOne()
            .HasForeignKey<Company>(da => da.DefaultBillingAddressId)
            .IsRequired(false)
            .HasConstraintName("FK_COMPANY_DEFAULT_BILLING_ADDRESS")
            .OnDelete(DeleteBehavior.Restrict);
        builder
            .HasOne(s => s.DefaultDeliveryAddress)
            .WithOne()
            .HasForeignKey<Company>(da => da.DefaultDeliveryAddressId)
            .HasConstraintName("FK_COMPANY_DEFAULT_DELIVERY_ADDRESS");
...

您可以查看 and 个相关答案。

Answer 2

这是处理此问题并将关系直接配置到模型中的另一种方法。

public class Company : AbstractValidatableEntity
{
    public string Name { get; set; }
    public List<User> Users { get; set; }
    public Guid OwnerId { get; set; }
    public User Owner { get; set; }

    [InverseProperty("Companies")]    
    public List<Address> Addresses { get; set; }
    
    [InverseProperty("HostedCompanies")]
    [ForeignKey("DefaultAdressID")]
    public Address DefaultAddress { get; set; }
    public Guid DefaultAddressID { get; set; }

    [InverseProperty("BillingCompanies")]
    [ForeignKey("DefaultBillingAddressID")]
    public Address DefaultBillingAddress { get; set; } 
    public Guid DefaultBillingAddressID { get; set; }

    [InverseProperty("DeliveryCompanies")]
    [ForeignKey("DefaultDeliveryAddressID")]
    public Address DefaultDeliveryAddress { get; set; }
    public Guid DefaultDeliveryAddressID { get; set; }
}

在您的地址模型中添加这些

public class Address {
    ...
    public ICollection<Company> Companies { get; set; }
    public ICollection<Company> HostedCompanies { get; set; }
    public ICollection<Company> BillingCompanies { get; set; }
    public ICollection<Company> DeliveryCompanies{ get; set; }
    ...
}

现在您可以删除 CompanyAddress class，它不再可用了。实际上，引擎盖下的 EF 会生成 CompanyAddress table 给你。你也可以清除你的 modelBuilder:

public override void Configure(EntityTypeBuilder<Company> builder)
    {
        base.Configure(builder);
        
        // Table name
        builder
            .ToTable("Companies");
        
        // Columns
        builder
            .Property(s => s.Name)
            .IsRequired(true)
            .HasMaxLength(255);
        
        // Relationships
        builder
            .HasMany(s => s.Users)
            .WithOne(u => u.Company)
            .HasForeignKey(u => u.CompanyId)
            .IsRequired(false)
            .HasConstraintName("FK_COMPANY_USERS");
        
        // Indexes
        builder
            .HasIndex(s => s.Name)
            .HasDatabaseName("IX_COMPANY_NAME");
    }

EF Core Net 5 - Code First - 与同一实体的多种关系

EF Core Net 5 - Code First - Multiple relationships to same entity

c#

ef-core-5.0