实体框架中的覆盖种子方法

Question

I have an object Class :

 public  class Post
  {
     public int Id { get; set; }
     public string Title { get; set; }
     public string Content { get; set; }
  }

and i implemented a class to override Seed method like this :

 public class MyCustomInitialize : DropCreateDatabaseIfModelChanges<Context>
{
    protected override void Seed(Context context)
    {
        context.Posts.Add(new Post() { Content = "This is a test", Id = 2, Title = "my subject" });
        context.Database.ExecuteSqlCommand("CREATE INDEX IX_title ON Blog (title)");
        base.Seed(context);
    }
}

and in Program.cs :

 Database.SetInitializer(new  MyCustomInitialize());

but when i run my program, the record which i want to add to my DataBase ( with Title "my subject"), it didn't insert to my DB and the Index didn't create too! what is the problem?

Answer 1

您需要在DbContext上调用SaveChanges。

Answer 2

The SetInitializer call should be in your global.asax in the Application_Start() event.

protected void Application_Start()
{
    System.Data.Entity.Database.SetInitializer(new MyCustomInitialize());
}

EDIT: As amarano says in their answer the database has not been updated with the new 'Post' because you haven't called SaveChanges...

Which makes me wonder how are you inspecting whether the index has been applied?

Also you should call

Context.Entry(TheTrackedEntityYouWantToUpdate).Reload();

To update the local (in memory entity) after your ExecuteSqlCommand call.