无法生成控制器 [英] Unable To generate a Controller

问题描述

我希望在数据库中创建代码优先方法但是

我在生成控制器时继续出现此错误

我总是收到此错误消息



无法检索'Identifications.Models.Identification'的元数据。

值不能为空

参数名称： key



这是我的模特到目前为止

I wish to Create A Code First Approach in a Database But
I Keep on Getting This Error When I Generate a Controller
I Always Get This Error Message

Unable To Retrieve Metadata for 'Identifications.Models.Identification'.
Value Cannot be null
Parameter name: key

This is my Model so Far

namespace Identifications.Models
{
    public class Identification
    {

        public Int32 ID { get; set; }
        public string FullName { get; set; }
        public HttpPostedFileBase file { get; set; }

    }

    public class DbIdentification : DbContext
    {

        public DbSet<Identification> Identifications { get; set; }
    }
}

这是我的ConnectionString到目前为止

This is my ConnectionString so Far

<connectionstrings>
    <add name="DbIdentification">
         <connectionString="server=.; database=Sample; Integrated Security=SSPI"
          providerName="System.Data.SqlClient"/>    
</connectionstrings>

希望你能帮我一个大谢谢！

Hope You Can Help me Out Here A Big Thanks!

推荐答案

看到它用于学习示例代码拳头approuch。

http://weblogs.asp.net/scottgu/code-first-development-with-entity-framework-4 [< a href =http://weblogs.asp.net/scottgu/code-first-development-with-entity-framework-4target =_ blanktitle =New Window> ^ ] br />
http://codefirst.codeplex.com/ [ ^ ]

see it for learn with example code fist approuch.
http://weblogs.asp.net/scottgu/code-first-development-with-entity-framework-4[^]
http://codefirst.codeplex.com/[^]

EF需要在每张桌子上PK，所以你需要这个

EF require PK on each table so you need this

namespace Identifications.Models
{
public class Identification
{

[Key]
public Int32 ID { get; set; }
public string FullName { get; set; }
public HttpPostedFileBase file { get; set; }

}

你可以从这里使用更多选项

http://msdn.microsoft.com/en-in/data/jj591583.aspx [ ^ ]

这是代码第一个实体框架，你正在使用，所以Sql需要知道哪个是主键，它将设置。所以需要 [key] 属性。

关注这里 [ ^ ]

以上链接将为您提供代码优先约定。

谢谢

：）

This is code first entity framework, you are using so the Sql needs to know which is the primary key, it is going to set. So [key] attribute is needed.
Follow here[^]
Above link would give you code first conventions.
Thanks
:)

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