Create a Database with ADO.NET in Xamarin Android

First we need WriteExternalStorage Permission

Add a reference to System.Data and to Mono.Data.SQLite

// with Android.Graphics & Android.Environment
var docsFolder = System.Environment.GetFolderPath(System.Environment.SpecialFolder.MyDocuments);
var pathToDatabase = System.IO.Path.Combine(docsFolder, "db_adonet.db");
SqliteConnection.CreateFile(pathToDatabase);

// without Android.Graphics & Android.Environment
using System.IO;

var docsFolder = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
var pathToDatabase = Path.Combine(docsFolder, "db_adonet.db");
SqliteConnection.CreateFile(pathToDatabase);

// with try / catch
try
{
    var docsFolder = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
    var pathToDatabase = Path.Combine(docsFolder, "db_adonet.db");
    SqliteConnection.CreateFile(pathToDatabase);
}
catch (IOException ex)
{
    var reason = string.Format("The database failed to create - reason {0}", ex.Message);
    Toast.MakeText(myContext, reason, ToastLength.Long).Show();
}

// using File.Exists
if (!File.Exists(pathToDatabase))
{
    var reason = string.Format("The database failed to create - reason {0}", ex.Message);
    Toast.MakeText(myContext, reason, ToastLength.Long).Show();
}

// create a connection string for the database
var connectionString = string.Format("Data Source={0};Version=3;", pathToDatabase);
            try
{
    using (var conn = new SqliteConnection((connectionString)))
    {
        await conn.OpenAsync();
        using (var command = conn.CreateCommand())
        {
            command.CommandText = "CREATE TABLE People (PersonID INTEGER PRIMARY KEY AUTOINCREMENT, FirstName ntext, LastName ntext)";
            command.CommandType = CommandType.Text;
            await command.ExecuteNonQueryAsync();
        }
    }
}
catch (Exception ex)
{
    var reason = string.Format("Failed to insert into the database - reason = {0}", ex.Message);
    Toast.MakeText(myContext, reason, ToastLength.Long).Show();
}

References :
https://developer.xamarin.com/recipes/android/data/databases/adonet/