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Question

我有以下两个实体：

public class Company
{
    public Guid Id { get; set; }
    public string Name { get; set; }

    public virtual ICollection<Address> Addresses { get; set; }
}

public class Address
{
    public Guid Id { get; set; }
    public string Town { get; set; }
    public string Country { get; set; }
}

这对应于两个数据库表：

Company:
  Id uniqueidentifier
  Name varchar

Address:
  Id uniqueidentifier
  Town varchar
  Country varchar
  RelationId uniqueidentifier

RelationId 是将链接存储回 CompanyId 的外键。

我不能更改类或表。

我试图弄清楚如何在代码优先的 EFCore 中表示此构造。

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<Company>().ToTable("Companies");
        modelBuilder.Entity<Address>().ToTable("Addresses");

        modelBuilder.Entity<Company>().HasKey(c => c.Id);
        modelBuilder.Entity<Address>().HasKey(c => c.Id);

        ???????????????????????
    }

我在上面的代码中缺少什么来防止创建 CompanyId 外键并改用“RelationId”。

Answer 1

按照@TanvirArjel 的目的，在地址中创建Guid RelationId 和Company 公司属性，并使用以下流畅配置：

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    .....

    modelBuilder.Entity<Company>()
        .HasOne(c => c.Address)
        .WithOne(a => a.Company)
        .HasForeignKey(a => a.RelationId);
}

如果一个地址可以有多个公司，请将WithOne 更改为WithMany 并将公司属性类型更改为ICollection<Company>

Answer 2

这是满足您要求的解决方案：

public class Company
{
    public Guid Id { get; set; }
    public string Name { get; set; }

    //remove virtual keyword as there is no lazy loading in  entityframework core
    public ICollection<Address> Addresses { get; set; }
}

public class Address
{
    public Guid Id { get; set; }

    [ForeignKey("Company ")]
    public Guid RelationId { get; set; }
    public string Town { get; set; }
    public string Country { get; set; }

    //remove virtual keyword as there is no lazy loading in  entityframework core
    public Company Company {get; set;}
}

使用 Fluent API：

public class YourDbContext : DbContext
{
    public DbSet<Company> Companies { get; set; }
    public DbSet<Address> Addresses { get; set; }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<Address>()
            .HasOne(p => p.Company)
            .WithMany(b => b.Addresses);
    }
}