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; }    }}模型：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;    }}數(shù)據(jù)庫表：CREATE TABLE [dbo].[studentdetails](    [RollNo] [int] NULL,    [Name] [nvarchar](50) NULL,    [Stream] [nvarchar](50) NULL,    [Div] [nvarchar](50) NULL)  在global.asax.cs中Database.SetInitializer<MvcApplication1.Models.studentContext>(null);上面的代碼列出了我正在處理的所有類。在運行我的應(yīng)用程序時收到錯誤：“模型生成期間檢測到一個或多個驗證錯誤”以及“實體類型未定義鍵”。