指定的模式无效。错误：没有装载的关系，因为该类型不可用 [英] Schema specified is not valid. Errors: The relationship was not loaded because the type is not available

问题描述

我想引用 OrderAddress 模式的两次我在订单模型;一次作为 ShippingAddress 一次作为 BillingAdress 。

I wish to reference the OrderAddress model twice in my Order model; once as a ShippingAddress and once as a BillingAdress.

在另一边，我希望我的 OrderAddress 模式对名单 OrderAddresses 。

On the other side, I want my OrderAddress model to have a list of OrderAddresses.

public enum AddressType
{
    Billing,
    Shipping,
    Contact
}
public class OrderAddress : BaseModel
{
    public AddressType AddressType { get; set; }
    public bool IsPrimary { get; set; }

    public string Address { get; set; }
    public string CityStateZip { get; set; }
    public string ContactName { get; set; }
    public string PhoneNumber { get; set; }
    public string FaxNumber { get; set; }
    public string EmailAddress { get; set; }

    public virtual ICollection<Order> Orders { get; set; }

    public virtual ApplicationUser User { get; set; }
}

订货型号

---

public class Order : BaseModel
{
    public DateTime OrderDate { get; set; }

    public int BillingAddressId { get; set; }
    public virtual OrderAddress BillingAddress { get; set; }

    public int ShippingAddressId { get; set; }
    public virtual OrderAddress ShippingAddress { get; set; }

    public virtual ApplicationUser User { get; set; }

}

流利的API

---

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    base.OnModelCreating(modelBuilder);

    modelBuilder.Entity<Order>()
                .HasRequired(m => m.ShippingAddress)
                .WithMany(t => t.Orders)
                .HasForeignKey(m => m.ShippingAddressId)
                .WillCascadeOnDelete(false);

    modelBuilder.Entity<Order>()
                .HasRequired(m => m.BillingAddress)
                .WithMany(t => t.Orders)
                .HasForeignKey(m => m.BillingAddressId)
                .WillCascadeOnDelete(false);
}

---

当我尝试运行更新的数据库，我收到以下错误：

---

When I try to run Update-Database, I get the following error:

指定的模式是无效的。错误：关系MyApp.Domain.DAL.Order_ShippingAddress未加载，因为类型'MyApp.Domain.DAL.OrderAddress不可用

Schema specified is not valid. Errors: The relationship 'MyApp.Domain.DAL.Order_ShippingAddress' was not loaded because the type 'MyApp.Domain.DAL.OrderAddress' is not available.

我在做什么错了？

推荐答案

该错误是有点神秘，所以我不知道这是你得到的特定错误的原因，但我知道它会导致的部分的错误，这样你就可以解决这个启动：

The error is a little cryptic, so I'm not sure if this is the reason you're getting that particular error, but I do know it will cause some error, so you can start by fixing this:

你有什么是两个一到多的关系，在一类相同的模型。这本身并不是一个问题，但你必须把它们当作独立的。换句话说，他们不能都具有订单的对立关系，因为相关法，也没有办法知道哪些外键关系应该填充该列表。如果你简单地改变你的流利的API定义为类似于 .WithMany（T =＆GT; t.Orders_Shipping）和 .WithMany（T =＆GT;吨.Orders_Billing），我认为这将清理你的错误。

What you have is two one-to-many relationships to the same model on one class. That's not a problem per se, but you have to treat them as separate. In other words, they can't both have a opposite relationship of Orders, because relationally, there's no way to know which foreign key relationship should populate that list. If you simply change your fluent API definition to something like .WithMany(t => t.Orders_Shipping) and .WithMany(t => t.Orders_Billing), I think that will clear up your error.

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