// I set the ItemSource in DbConnect.cs as follows:
//=====================================================================

public class PlotList
{
    public string Id { get; set; }
    public string PlotId { get; set; }
    public string Jobs { get; set; }
    public string Bids { get; set; }
}

public List<PlotList> SelectPlotLists()
{
    string query = "SELECT plot_id, postcode, jobs, bid from plot WHERE postcode ='" + Plot + "'";

    // Create a list to store the result
    var plotList = new List<PlotList>();

    // Create command
    var cmd = new MySqlCommand(query, _connection);
    MySqlDataReader dataReader = cmd.ExecuteReader();

    // Read the data and store it in a list
    while (dataReader.Read())
    {
        var item = new PlotList();
        item.PlotId = dataReader["plot_id"] + "";
        item.Jobs = dataReader["jobs"] + "";
        item.Bids = dataReader["bid"] + "";
        plotList.Add(item);
    }

    // Close
    dataReader.Close();

    // Return list
    return plotList;
}

//  I then set up the following method in MainWindow.xaml.cs and call it in MainWindow():
//=====================================================================

public void ResetPlot()
        {
            // Establish MySQL connection
            var dbObject = new DbConnect();
            dbObject.OpenConnection();

            // Fill plot list view
            List<DbConnect.PlotList> plotList = dbObject.SelectPlotLists();
            Dispatcher.BeginInvoke(
                new ThreadStart(() => PlotListView.ItemsSource = plotList));
        }