EntityType 没有键定义错误 [英] EntityType has no key defined error

问题描述

控制器:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using MvcApplication1.Models;
using System.ComponentModel.DataAnnotations.Schema;

namespace MvcApplication1.Controllers
{
    public class studentsController : Controller
    {
        //
        // GET: /students/

        public ActionResult details()
        {
            int id = 16;
            studentContext std = new studentContext();
           student first = std.details.Single(m => m.RollNo == id);
            return View(first);
        }

    }
}

DbContext 模型:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Data.Entity;

namespace MvcApplication1.Models
{
    public class studentContext : DbContext
    {
        public DbSet<student> details { get; set; }
    }
}

型号:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.ComponentModel.DataAnnotations.Schema;

namespace MvcApplication1.Models
{
    [Table("studentdetails")]
    public class student
    {
        public int RollNo;
        public string Name;
        public string Stream;
        public string Div;
    }
}

数据库表:

CREATE TABLE [dbo].[studentdetails](
    [RollNo] [int] NULL,
    [Name] [nvarchar](50) NULL,
    [Stream] [nvarchar](50) NULL,
    [Div] [nvarchar](50) NULL
)  

在 global.asax.cs

Database.SetInitializer<MvcApplication1.Models.studentContext>(null);

上面的代码列出了我正在研究的所有类.运行我的应用程序时收到错误:

The above code lists all the classes I am working on. Upon running my application am receiving the error:

在模型生成过程中检测到一个或多个验证错误"以及实体类型未定义键".

"One or more validation errors were detected during model generation" along with "Entity type has no key defined".

推荐答案

Model 类应该改为:

The Model class should be changed to :

using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.ComponentModel.DataAnnotations.Schema;
using System.ComponentModel.DataAnnotations;

namespace MvcApplication1.Models
{
    [Table("studentdetails")]
    public class student
    {
        [Key]
        public int RollNo { get; set; }

        public string Name { get; set; }

        public string Stream { get; set; }

        public string Div { get; set; }
    }
}

这篇关于EntityType 没有键定义错误的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！