实体框架5 - 无效的列名称 - 逆向工程师代码第一 [英] Entity Framework 5 - Invalid column name - Reverse Engineer Code First

问题描述

实体框架5 ， Visual Studio 2010 与实体框架电动工具（Beta 2）扩展。

这是我的数据库表结构：

我使用上述扩展名的逆向工程师代码优先功能，它生成了POCO类和一些映射文件（不知道这是否是正式的说明）和一个单独的DbContext派生类。除了下面描述的变化之外，所有这些生成的类都是由电动工具生成的。

在Category.cs文件中，我添加了以下代码帮助平铺对象图：

  private ICollection< Product> m_Products = null; 
 public ICollection< Product>产品
 {
 get 
 {
 if（m_Products == null）
 {
 m_Products = new List< Product>（）; 
 foreach（var categoryProduct in CategoryProducts）
 {
 m_Products.Add（categoryProduct.Product）; 
} 
} 
返回m_Products; 
} 
 set {m_Products = value; } 
} 
  

我得到以下例外，我知道必须与映射，但我只是不能很清楚这一点。

 未处理的异常：System.Data.EntityCommandExecutionException：发生错误而
执行命令定义。查看内部例外情况。 
 ---> System.Data.SqlClient.SqlException：
列名Category_CategoryId无效。 
  

如果我需要发布更多信息，例如映射的具体细节，只需让我知道我会做的。我想保持尽可能的短，但我意识到我已经省略了一些事情，对于那些不熟悉该工具生成的代码的人来说，可能会留下更多的细节。

解决方案

您已将导航属性添加到模型中，因此EF正在尝试将其映射到数据库。 Code First表示您的代码模型定义了您的数据库模式。

尝试将 [NotMapped] 属性添加到您的帮助人员告诉EF忽略它们。

Using Entity Framework 5, Visual Studio 2010 with the Entity Framework Power Tools (Beta 2) extension.

Here is my database table structure:

I used the Reverse Engineer Code First function of the aforementioned extension, which generated the POCO classes and some 'mapping' files (not sure if that's the formal parlance) and a single DbContext-derived class. Other than the change I describe next, all of these generated classes are as-generated by the power tool.

In the Category.cs file, I added the following code to help flatten the object graph a bit:

private ICollection<Product> m_Products = null;
public ICollection<Product> Products
{
    get
    {
        if (m_Products == null)
        {
            m_Products = new List<Product>();
            foreach (var categoryProduct in CategoryProducts)
            {
                m_Products.Add(categoryProduct.Product);
            }
        }
        return m_Products;
    }
    set { m_Products = value; }
}

I get the following exception, which I know must have something to do with the mappings, but I just can't quite figure this out.

Unhandled Exception: System.Data.EntityCommandExecutionException: An error occurred while 
executing the command definition. See the inner exception for details.
 ---> System.Data.SqlClient.SqlException: 
      Invalid column name 'Category_CategoryId'.

If I need to post more information, such as the specifics of the mappings, just let me know and I'll do it. I wanted to keep this as short as possible, but I realize I've omitted some things that, for those unfamiliar with the code generated by the tool, may leave one wanting for more details.

解决方案

You've added a navigation property to your model and so EF is trying to map that to your database. "Code First" means your code model defines your database schema.

Try adding the [NotMapped] attribute to your helper properties to tell EF to ignore them.

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