SetUp

MainPage.xaml.cs

namespace com.example.hello
{
    public partial class MainPage : PhoneApplicationPage
    {
        // Constructor
        public MainPage()
        {
            InitializeComponent();
            
            this.CordovaView.Loaded += CordovaView_Loaded;
        }

        private async void CordovaView_Loaded(object sender, RoutedEventArgs e)
        {
            await CopyDatabase();
            this.CordovaView.Loaded -= CordovaView_Loaded;
        }

        private async Task CopyDatabase()
        {
            bool isDatabaseExisting = false;

            try
            {
                StorageFile storageFile = await ApplicationData.Current.LocalFolder.GetFileAsync("my.db");
                isDatabaseExisting = true;
            }
            catch
            {
                isDatabaseExisting = false;
            }

            if (!isDatabaseExisting)
            {
                StorageFile databaseFile = await Package.Current.InstalledLocation.GetFileAsync("my.db");
                await databaseFile.CopyAsync(ApplicationData.Current.LocalFolder);
            }
        }
    }
}

Screenshot

Here is a screenshot of the ".db"-File and of course the "Exception" which was thrown in the console
http://imgur.com/eKWjMjS

Of course I changed the Database-attributes from Build "Content" to "Resource" but it didn't worked. 

"Immer kopieren" means "Always copy"