我的数据库不是通过Entity Framework 6代码优先方法自动创建的吗？

Question

I am trying to create a database using code first approach for an online exam system. I have already created my data models, my context class, added my setInitializer method in the Global.asax file, added my connection string.

But still the database isn't getting created. Would really use some help.

My connection string :

<connectionStrings>
    <add name="ExamDbContext" 
         connectionString="server=LAPTOP-JJKI9JN7; Initial Catalog=OnlineExamSystem; Integrated Security=true;" 
         providerName="System.Data.SqlClient">
    </add> 
</connectionStrings>

LAPTOP-JJKI9JN7 is my SSMS server name

Student table:

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

namespace Online_Exam_System.Models
{
    public class TBL_STUDENT
    {
        public int S_ID { get; set; }

        [Display(Name = "Student")]
        [Required(ErrorMessage = "The field is required")]
        public string S_NAME { get; set; }

        [Display(Name = "Password")]
        [Required(ErrorMessage = "The field is required")]
        public string S_PASSWORD { get; set; }

        [Display(Name = "Marks")]
        [Required(ErrorMessage = "The field is required")]
        public Nullable<int> S_MARKS { get; set; }
    }
}

Question table :

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

namespace Online_Exam_System.Models
{
    public class TBL_QUESTIONS
    {
        public int QUESTION_ID { get; set; }

        [Display(Name = "Question")]
        [Required(ErrorMessage = "The field is required")]
        public string QUESTION_TEXT { get; set; }


        public string OPTION { get; set; }

        [Display(Name = "OPTION A")]
        [Required(ErrorMessage = "The field is required")]
        public string OPTIONA { get; set; }

        [Display(Name = "OPTION B")]
        [Required(ErrorMessage = "The field is required")]
        public string OPTIONB { get; set; }

        [Display(Name = "OPTION C")]
        [Required(ErrorMessage = "The field is required")]
        public string OPTIONC { get; set; }

        [Display(Name = "OPTION D")]
        [Required(ErrorMessage = "The field is required")]
        public string OPTIOND { get; set; }

        public string CORRECT { get; set; }
    }
}

Admin table:

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

namespace Online_Exam_System.Models
{
    public class TBL_ADMIN
    {
        public int AD_ID { get; set; }

        [Display(Name = "User Name")]
        [Required(ErrorMessage = "The field is required")]
        public string AD_NAME { get; set; }

        [Display(Name = "Password")]
        [Required(ErrorMessage = "The field is required")]
        [DataType(DataType.Password)]
        public string AD_PASSWORD { get; set; }
    }
}

My context class

using System.Collections.Generic;
using System.Data.Entity;
using System.Data.Entity.Infrastructure;
using Online_Exam_System.Models;
using System.Linq;
using System.Web;
using System.Data.Entity.ModelConfiguration.Conventions;

namespace Online_Exam_System.Data_Access_Layer
{
    public class ExamDbContext : DbContext
    {
        public ExamDbContext() : base("ExamDbContext")
        {
        }

        public DbSet<TBL_ADMIN> TBL_ADMIN { get; set; }
        public DbSet<TBL_QUESTIONS> TBL_QUESTIONS { get; set; }
        public DbSet<TBL_EXAM> TBL_SETEXAM { get; set; }
        public DbSet<TBL_STUDENT> TBL_STUDENT { get; set; }

        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();
        }
    }
}

My Initializer method (it's inside the Model folder)

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

namespace Online_Exam_System.Models
{
    public class ExamInitializer : CreateDatabaseIfNotExists<ExamDbContext>
    {
        protected override void Seed(ExamDbContext context)
        {
            base.Seed(context);
        }
    }
}

Global.asax file:

    using System;
    using System.Collections.Generic;
    using System.Data.Entity;
    using System.Linq;
    using System.Web;
    using System.Web.Mvc;
    using System.Web.Optimization;
    using System.Web.Routing;

    namespace Online_Exam_System
    {
            public class MvcApplication : System.Web.HttpApplication
            {
                protected void Application_Start()
                {
                    Database.SetInitializer(new 
                    NullDatabaseInitializer<ExamDbContext>());
                    AreaRegistration.RegisterAllAreas();

                    FilterConfig.RegisterGlobalFilters
                    (GlobalFilters.Filters);
                    RouteConfig.RegisterRoutes(RouteTable.Routes);
                    BundleConfig.RegisterBundles(BundleTable.Bundles);
       }
}

Answer 1

After you set your initializer, force it to run by either accessing the context somewhere or forcing it:

Database.SetInitializer(new NullDatabaseInitializer<ExamDbContext>());
// Forces initialization of database on model changes.
using (var context= new ExamDbContext ()) {
   context.Database.Initialize(false);
}    

Forcing code-first to always initialize a non-existent database?