xamarin.forms: retrieving existing data from .db file - database

Question

In Xamarin Forms 4.3, I'm following this "Local Databases" doc: https://learn.microsoft.com/en-us/xamarin/xamarin-forms/data-cloud/data/databases
This doc explains how to create and use a new sqlite db, but how do I go about in loading and displaying data in an existing .db file with the end purpose of transferring it into a new local sqlite database?
using SQLite;
namespace TruckExample.Models
{
public class Truck
{
[PrimaryKey, AutoIncrement]
public int TruckNo { get; set; }
public string TruckName { get; set; }
}
}
//////////////////////////////////////////////
using System.Collections.Generic;
using System.Threading.Tasks;
using SQLite;
using TruckExample.Models;
namespace TruckExample.Data
{
public class TruckDatabase
{
readonly SQLiteAsyncConnection _database;
public TruckDatabase(string dbPath)
{
_database = new SQLiteAsyncConnection(dbPath);
_database.CreateTableAsync<Truck>().Wait();
}
public Task<List<Truck>> GetTrucksAsync()
{
return _database.Table<Truck>().ToListAsync();
}
}
}
////////////////////////////////////////////////
using System;
using Xamarin.Forms;
using Xamarin.Forms.Xaml;
using TruckExample.Data;
using System.IO;
[assembly: XamlCompilation(XamlCompilationOptions.Compile)]
namespace TruckExample
{
public partial class App : Application
{
static TruckDatabase database;
public static TruckDatabase Database
{
get
{
if(database == null)
{
database = new TruckDatabase(Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData), "Truck.db"));
}
return database;
}
}
public App()
{
InitializeComponent();
MainPage = new NavigationPage(new MainPage());
}
}
}
/////////////////////////////////////////
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Xamarin.Forms;
using Xamarin.Forms.Xaml;
namespace TruckExample
{
[XamlCompilation(XamlCompilationOptions.Compile)]
public partial class MainPage : ContentPage
{
public MainPage ()
{
InitializeComponent ();
}
protected override async void OnAppearing()
{
base.OnAppearing();
listView.ItemsSource = await App.Database.GetTrucksAsync();
Debug.Write(App.Database.GetTrucksAsync());
}
}
}

Answer 1

For others, helpful resources:
Implementation by Hameed Kunkanoor: "Creating a sqlite databse and storing your data in your android and ios application in Xamarin Forms" https://medium.com/#hameedkunkanoor/creating-a-sqlite-databse-and-storing-your-data-in-your-android-and-ios-application-in-xamarin-2ebaa79cdff0
(Refer to his git if needed)
Explanation/response by Matthewrdev: Use a local database in Xamarin
To improve the implementation -- Brandon Minnick: "Xamarin: Efficiently Using a SQLite Database" https://codetraveler.io/2019/11/26/efficiently-initializing-sqlite-database/