when i restart my emulator i cannot retrieve database values in sqlite windows phone 8.1

I designed a login and registration page using Sqlite database in windows phone 8.1. With the following code I can successfully insert and retrieve the values from sqlite database. But it happens only once. When I restart my emualator I cannot retrieve the values from database.

 protected async override void OnNavigatedTo(NavigationEventArgs e)
    {
        var dbpath = ApplicationData.Current.LocalFolder.Path + "/ebook.db";
        var con = new SQLiteAsyncConnection(dbpath);
        await con.CreateTableAsync<Register>();
    }
    private async void Button_Click(object sender, RoutedEventArgs e)
    {
        var dbpath = ApplicationData.Current.LocalFolder.Path + "/ebook.db";
        var con = new SQLiteAsyncConnection(dbpath);
        await con.CreateTableAsync<Register>();
        Register m = new Register();

        m.Name = text_reg.Text;
        m.Password = text_password.Password;
        string rd = "";
        if (radio_male.IsChecked == true)
        {
            rd = "Male";

        }
        else
        {
            rd = "Female";

        }
        m.Gender = rd;
        m.State = ((ComboBoxItem)combo_box.SelectedItem).Content.ToString();


        await con.InsertAsync(m);

        MessageDialog md = new MessageDialog("success");
        await md.ShowAsync();
    }

    private async void Button_Click_1(object sender, RoutedEventArgs e)
    {

        var dbpath = ApplicationData.Current.LocalFolder.Path + "/ebook.db";
        var con = new SQLiteAsyncConnection(dbpath);

        Register t = new Register();
        string query = string.Format("select Name,Password from Register where Name='{0}' and Password='{1}'", text_user.Text, text_pass.Password);
        List<Register> mylist = await con.QueryAsync<Register>(query);
        if (mylist.Count == 1)
        {
            t = mylist[0];
        }

        if (t.Name == text_user.Text && t.Password == text_pass.Password)
        {

            this.Frame.Navigate(typeof(MainPage));
        }
        else
        {
            var messagedialog = new MessageDialog("Unsuccessful").ShowAsync();
        }
    }
}