无效列名称错误当试图用的EntityFramework到关联对象 [英] Invalid Column Name Error When Trying to Associate Objects with EntityFramework

问题描述

实体框架是给我一些麻烦。

The entity framework is giving me some trouble.

下面是我的表：

产品

相关产品

和我的数据库环境（它的一部分，反正）...

And my DB context (part of it, anyway)...

ApplicationContext.cs

public class ApplicationContext : DbContext
{
        public ApplicationContext() : base("DefaultConnection")
        {
        }

        public DbSet<Product> Products { get; set; }
        public DbSet<RelatedProduct> RelatedProducts { get; set; }
}

和模型......

Product.cs

public class Product
{
    public int ID              { get; set; }
    public string Manufacturer { get; set; }
    public string Model        { get; set; }
    public string PartNumber   { get; set; }
    public int CategoryID      { get; set; }
    public string Description  { get; set; }
    public decimal Price { get; set; }

    public virtual ICollection<RelatedProduct> RelatedProducts { get; set; }
}

RelatedProduct.cs

public class RelatedProduct
{
    public int ID        { get; set; }
    public int OwnerID   { get; set; }
    public int ProductID { get; set; }

    public virtual Product Owner { get; set; }
    public virtual Product Product { get; set; }
}

我所试图做的

通过这样的相关产品列表循环：

What I am trying to do

Loop through a list of related products like this:

<ul class="activity">
      @foreach (var related in @Model.RelatedProducts)
      {
             <li>
                  <i class="fa fa-chevron-right red"></i> <strong>@related.Product.Manufacturer:</strong> @related.Product.Model
             </li>
      }
</ul>

问题

我不断收到这个errorL

The Problem

I keep getting this errorL

{"Invalid column name 'Product_ID'.\r\nInvalid column name 'Product_ID'.\r\nInvalid column name 'Product_ID'."}

任何想法？

推荐答案

您必须告诉EF如果 Product.RelatedProducts 是逆导航属性RelatedProduct.Owner 或 RelatedProduct.Product 的。双方将有可能有效和EF不能决定它自己的。

You must tell EF if Product.RelatedProducts is the inverse navigation property of RelatedProduct.Owner or of RelatedProduct.Product. Both would be possible and valid and EF can't decide it on its own.

与数据的注解解决方案（假设所有者是逆 RelatedProducts ）

Solution with data annotations (assuming Owner is the inverse of RelatedProducts):

[InverseProperty("RelatedProducts")]
public virtual Product Owner { get; set; }

public virtual Product Product { get; set; }

或用流利的API：

modelBuilder.Entity<RelatedProduct>()
    .HasRequired(r => r.Owner)
    .WithMany(p => p.RelatedProducts)
    .HasForeignKey(r => r.OwnerID);

modelBuilder.Entity<RelatedProduct>()
    .HasRequired(r => r.Product)
    .WithMany()
    .HasForeignKey(r => r.ProductID)
    .WillCascadeOnDelete(false);

大概只有流利的API解决方案将工作，因为你还需要禁用级联删除这是不可能的数据注解关系之一。

Probably only the Fluent API solution will work because you also need to disable cascading delete for one of the relationships which isn't possible with data annotations.

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