public static void RefreshPlot()
            {
                string query = "SELECT Count(*) AS count, plot_id FROM booking WHERE postcode=@postcode AND " +
                               "status='open' GROUP BY plot_id";
                var cmd = new MySqlCommand(query, DbConnect.Connection);
                cmd.Parameters.AddWithValue(("@postcode"), DbConnect.Plot);

                var da = new MySqlDataAdapter(cmd);
                var dtCounts = new DataTable();
                da.Fill(dtCounts);

                if (dtCounts.Rows.Count > 0)
                {
                    query = "UPDATE plot SET jobs = @jobCount WHERE plot_id = @plotID AND postcode=@postcode;";

                    query += "UPDATE plot " +
                             "LEFT JOIN booking " +
                             "ON plot.plot_id = booking.plot_id " +
                             "SET plot.jobs = 0 " +
                             "WHERE plot.postcode=@postcode " +
                             "AND booking.plot_id IS NULL;";

                    query += "update plot p " +
                             "inner join " +
                             "(select sum(case when status = 'Open' then 1 else 0 end) cnt, plot_id " +
                             "from booking group by plot_id) p2 on p.plot_id = p2.plot_id " +
                             "set p.jobs = p2.cnt;";

                    cmd = new MySqlCommand(query, DbConnect.Connection);
                    foreach (DataRow row in dtCounts.Rows)
                    {
                        cmd.Parameters.Clear();
                        cmd.Parameters.AddWithValue(("@postcode"), DbConnect.Plot);
                        cmd.Parameters.AddWithValue("@jobCount", int.Parse(row["count"].ToString()));
                        cmd.Parameters.AddWithValue("@plotID", int.Parse(row["plot_id"].ToString()));
                        cmd.ExecuteNonQuery();
                    }
                }
                else if ((dtCounts.Rows.Count == 0))
                {
                    query = "UPDATE plot SET jobs=0 WHERE postcode=@postcode;";
                    cmd = new MySqlCommand(query, DbConnect.Connection);
                    cmd.Parameters.AddWithValue(("@postcode"), DbConnect.Plot);
                    cmd.ExecuteNonQuery();
                }
            }