在MVC类上创建主键字段 [英] Creating Primary Key field on MVC class

问题描述

我是MVC和C＃的新手。我只是偶然发现，发现它很有趣。我遇到一个不允许我继续进行的问题。
这是我的代码：

  using System; 
使用System.Collections.Generic; 
使用System.Linq; 
使用System.Web; 
使用System.Web.Mvc; 
 
命名空间MyHotel.Models 
 {
 public class AccountTypes 
 {
 public int AccountTypeID {get;组; } 
 public string AccountTypeName {get;组; } 
} 
} 
  

此后创建了控制器和视图。 / p>

为此，我发现这个错误：

在模型生成期间检测到一个或多个验证错误：

  System.Data.Edm.EdmEntityType：：EntityType'AccountTypes'没有定义键。定义此EntityType的键。 
 System.Data.Edm.EdmEntitySet：EntityType：EntitySetAccountTypes基于没有键定义的类型AccountTypes。 
  

我google答案是要添加 [Key] 超过 public int AccountTypeID {get;组; } 所以可能如下所示：

 命名空间MyHotel.Models 
 {
 public class AccountTypes 
 {
 [Key] 
 public int AccountTypeID {get;组; } 
 public string AccountTypeName {get;组; } 
} 
} 
  

但直到现在还没有结果。
注意：我正在使用MVC 4

解决方案

描述

实体框架CodeFirst默认情况下，按名称识别密钥。
有效的名称是 Id 或< YourClassName> Id 。

您的财产应命名为 Id 或 AccountTypesId

另一种方法是使用 ModelBuilder 来指定密钥。

样本

  public class MyDbContext：DbContext 
 {
 public DbSet< AccountTypes> AccountTypes {get;组; 
 
 protected override void OnModelCreating（ModelBuilder modelBuilder）
 {
 modelBuilder.Entity< AccountTypes> .HasKey（x => x.AccountTypeID）; 
 base.OnModelCreating（modelBuilder）; 
} 
} 
  

模式信息

• 实体框架代码第一个教程

I am new to MVC and C#. I just stumbled on it and found it interesting. I encountered an issue which will not allow me proceed. Here is my code:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc; 

namespace MyHotel.Models
{
    public class AccountTypes
    {
        public int AccountTypeID { get; set; }
        public string AccountTypeName { get; set; }
    }
}

I created the controler and the view thereafter.

And for this, I keep got this error:

One or more validation errors were detected during model generation:

System.Data.Edm.EdmEntityType: : EntityType 'AccountTypes' has no key defined. Define the key for this EntityType.
System.Data.Edm.EdmEntitySet: EntityType: EntitySet "AccountTypes" is based on type "AccountTypes" that has no keys defined.

I google that the answers were to add [Key] over the public int AccountTypeID { get; set; } so it could look like this:

namespace MyHotel.Models
{
    public class AccountTypes
    {
        [Key]
        public int AccountTypeID { get; set; }
        public string AccountTypeName { get; set; }
    }
}

But no result until now. Note: I am using MVC 4

解决方案

Description

Entity Framework CodeFirst recognize the key, by default, by name. Valid names are Id or <YourClassName>Id.

Your property should named Id or AccountTypesId

Another way is to use the ModelBuilder to specify the key.

Sample

public class MyDbContext : DbContext
{
    public DbSet<AccountTypes> AccountTypes { get; set; }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<AccountTypes>.HasKey(x => x.AccountTypeID);
        base.OnModelCreating(modelBuilder);
    }
}

Mode Information

• Entity Framework Code First Tutorial

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