Deploying MVC3 web application

Question

Good day all, I am trying to deploy my ASP.NET MVC3 app to my webserver. This is what I've done:

1. Uploaded all the project to the web server
2. Created a new empty DB, ran SQL scripts to create the tables and PKs
3. Modified the web.config file's connectionString attribute to point to the online DB
4. added customErrors mode="On" to web.config

Here is what error I get:

Sorry, an error occurred while processing your request.

System.InvalidOperationException: The cast to value type 'Int32' failed because the materialized value is null. Either the result type's generic parameter or the query must use a nullable type.

Here is my code for the page I am requesting:

public ActionResult Index()
{
    ViewBag.Message = "Last game is #" + this.getLastGameId();
    return View();
}

public int getLastGameId()
{
    using (HockeyStatsEntities context = new HockeyStatsEntities())
    {
        return context.Dim_Game.Select(g => g.Game_id).Max();
    }
}

I am guessing this is because the tables are empty so that when my query to the db is returning null, that generates the error.

Answer 1

Max() throws this exception if there aren't any rows.

You can fix that by casting game_id to an int?, which will cause Max() to return null.
You could also call .DefaultIfEmpty().