MVC woes

So, I am diligently working with MVC 3... and ran into a very simple but convoluted problem. I was working with EF "code first" model and modified my model to add some validations...

Guess what ? It stopped running after that. Kept repeating the following message:

The model backing the 'MyDBContext' context has changed since the database was created. Either manually delete/update the database, or call Database.SetInitializer with an IDatabaseInitializer instance. For example, the DropCreateDatabaseIfModelChanges strategy will automatically delete and recreate the database, and optionally seed it with new data.

Solution:
We need to update the table in Sql Server to have the additional column you added to your entitiy class.

Database.SetInitializer(new DropCreateDatabaseIfModelChanges());

This line is used for in order to allow to edit database by making changes to Model objects.Add this line in Global.asax at Application_Start() method.

Inside the Application_Start method, define the Database initializer with one among the two options.

DropCreateDatabaseAlways: This will drop and recreate the database in every application start.

DropCreateDatabaseIfModelChanges: This will drop and create the database only if the underlined model changes.

Sample code:

protected void Application_Start()
{
Database.SetInitializer(newDropCreateDatabaseIfModelChanges());

AreaRegistration.RegisterAllAreas();

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

Now it is working perfectly.

Note: DropCreateDatabaseIfModelChanges should only be use early on in development, never on a production machine. If you pushed to a production machine and made schema changes, you'd loose all your data.