Question

I just started trying my hands on EF4 code first this morning and I created my POCO, data context and Initializer classes in a separate class library, I believe it’s the regular boiler plate type code. I reference the class in an MVC3 application and set the initializer in the Global.asax. On running the app, I notice the following problems
1. No database is created anywhere (Then I add an entry in the web.config for a connection string named after the Context class, still no result)
2. When I try to access the initalized values, I get a null error, obviously because there is no data.

Can anyone please help me with pointers on how to get thi thing to work (would be a shame if I spent my entire christmas day learning this and I still can’t get it to work 🙁 )
Thanks
p.s. I tried inserting break points and I hit the app initialization method, but it never hits the Seed method in the initializer even though I add a break point there as well!!
Thanks.
Initializer class

    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Data.Entity;
    using F2AController.Models;

    namespace F2AController.DataObjects
    {
        public class F2AInitializer : DropCreateDatabaseAlways<F2AContext>
        {
            protected override void Seed(F2AContext context)
            {
                var countries = new List<Country> 
                {
                    new Country(){ CountryName="Germany", Active = true},
                    new Country(){ CountryName="Britain", Active = true}
                };
                countries.ForEach(s => context.Countries.Add(s));
                context.SaveChanges();
                var providers = new List<Providers>() 
                {
                    new Providers(){ ProviderName="InfoBip", ContactDetails="Rturo Manovic", Active=true, MessageRates= new List<ProviderRates>(){new ProviderRates(){ CountryId=1, DateCreated=DateTime.Now, DateModified=DateTime.Now, Rate=0.05M, Active=true}}}
                };
                providers.ForEach(p => context.Providers.Add(p));
                context.SaveChanges();
                var usermobiles = new List<MobileTerminal>()
                {
                    new MobileTerminal(){ Active= true, Credits=200, DateCreated=DateTime.Now, MSISDN="4477565444865"}
                };
                usermobiles.ForEach(u => context.MobileTerminals.Add(u));

                context.SaveChanges();
            }


        }
    }

Context Class

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

namespace F2AController.Models
{
    public class F2AContext : DbContext
    {
        public DbSet<Country> Countries;
        public DbSet<MobileTerminal> MobileTerminals;
        public DbSet<Providers> Providers;
        public DbSet<ProviderRates> ProviderRates;
        public DbSet<Property> Properties;
        public DbSet<ShortMessage> ShortMessages;
        public DbSet<UserProperties> UserProperties;

        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            base.OnModelCreating(modelBuilder);
        }
    }
}

Global.asax App initialization method

    protected void Application_Start()
    {
        AreaRegistration.RegisterAllAreas();
        Database.DefaultConnectionFactory = new SqlConnectionFactory(ConfigurationManager.ConnectionStrings["F2AContext"].ConnectionString);
        Database.SetInitializer<F2AContext>(new F2AInitializer());

        RegisterGlobalFilters(GlobalFilters.Filters);
        RegisterRoutes(RouteTable.Routes);
    }

Answer 1

Eureka..finally!
While searching for a solution, I came across this post Entity Framework Database.SetInitializer simply not working
Applying the solution suggested there to force my database to create worked at start up like I expected, but then while running the seed code, it threw a null pointer exception. While investigating, I realized that any attempt to reference the DBSet collections from the Context class yielded the same exception. Inspecting further I realised that instead of using

 public DbSet<MobileTerminal> MobileTerminals { get; set; }

I had used

   public DbSet<MobileTerminal> MobileTerminals;

Which meant that I did not get any implicit object initialization, hence the null pointer exception. I removed the forced initialization code and ran the app again, this time the seed code didn’t run until I accessed a page which actually queried the data context and it ran perfectly.
Apparently, due to Lazy loading, the initialization code is not run until it is actually needed, i.e. the first time the data context is queried in the application.

I hope this helps anyone who has the same problem in the future.