bazar.CashBalance.UpdateBalance C# (CSharp) Method

        void UpdateBalance()
        {
            TreeIter iter;
            if (BalanceTreeStore == null)
                return;
            BalanceTreeStore.Clear ();
            decimal TotalExpense = 0m;
            decimal TotalIncome = 0m;
            try {
                // Расходы
                string sqlwhere = "";
                string sqlwhere2 = "";
                if (comboCash.GetActiveIter (out iter) && comboCash.Active != 0) {
                    sqlwhere += " AND cash_id = '" + comboCash.Model.GetValue (iter, 1) + "'";
                    sqlwhere2 += " AND credit_slips.cash_id = '" + comboCash.Model.GetValue (iter, 1) + "'";
                }
                if (comboOrg.GetActiveIter (out iter) && comboOrg.Active != 0) {
                    sqlwhere += " AND org_id = '" + comboOrg.Model.GetValue (iter, 1) + "'";
                    sqlwhere2 += " AND credit_slips.org_id = '" + comboOrg.Model.GetValue (iter, 1) + "'";
                }
                string sql = "SELECT expense_items.name as item, SUM(amount) as sum FROM ( " +
                             "SELECT expense_id, SUM(sum) as amount FROM debit_slips " +
                             "WHERE operation != 'advance' AND date BETWEEN @start AND @end " + sqlwhere + " " +
                             "GROUP BY expense_id " +
                             "UNION ALL SELECT expense_id, SUM(sum) as amount FROM advance " +
                             "WHERE date BETWEEN @start AND @end " + sqlwhere + " " +
                             "GROUP BY expense_id ) as result " +
                             "LEFT JOIN expense_items ON result.expense_id = expense_items.id GROUP BY expense_id ";

                MySqlCommand cmd = new MySqlCommand (sql, QSMain.connectionDB);
                cmd.Parameters.AddWithValue ("@start", dateCashStart.Date);
                cmd.Parameters.AddWithValue ("@end", dateCashEnd.Date.AddDays (1));
                MySqlDataReader rdr = cmd.ExecuteReader ();

                TreeIter FirstLevelIter;

                FirstLevelIter = BalanceTreeStore.AppendValues ("Статьи расходов");

                while (rdr.Read ()) {
                    TotalExpense += rdr.GetDecimal ("sum");
                    BalanceTreeStore.AppendValues (FirstLevelIter,
                                                   rdr ["item"].ToString (),
                                                   string.Format ("{0:C}", rdr.GetDecimal ("sum")));
                }
                BalanceTreeStore.AppendValues ("Итого:",
                                               string.Format ("{0:C}", TotalExpense));
                rdr.Close ();
                BalanceTreeStore.AppendNode ();

                // Доходы
                sql = "SELECT income_items.name as item, SUM(sumtable.total) as sum FROM (" +
                "SELECT income_id, SUM(sum) as total FROM credit_slips " +
                "WHERE operation = 'common' AND date BETWEEN @start AND @end " + sqlwhere + " " +
                "GROUP BY income_id " +
                "UNION ALL " +
                "SELECT payment_details.income_id as income_id, SUM(payment_details.sum) as total " +
                "FROM payment_details, payments, credit_slips " +
                "WHERE payment_details.payment_id = payments.id AND payments.credit_slip_id = credit_slips.id " +
                "AND credit_slips.operation = 'payment' AND credit_slips.date BETWEEN @start AND @end " + sqlwhere2 + " " +
                "GROUP BY payment_details.income_id ) as sumtable " +
                "LEFT JOIN income_items ON income_id = income_items.id " +
                "GROUP BY sumtable.income_id";

                cmd = new MySqlCommand (sql, QSMain.connectionDB);
                cmd.Parameters.AddWithValue ("@start", dateCashStart.Date);
                cmd.Parameters.AddWithValue ("@end", dateCashEnd.Date.AddDays (1));
                rdr = cmd.ExecuteReader ();

                FirstLevelIter = BalanceTreeStore.AppendValues ("Статьи Доходов");

                while (rdr.Read ()) {
                    TotalIncome += rdr.GetDecimal ("sum");
                    BalanceTreeStore.AppendValues (FirstLevelIter,
                                                   rdr ["item"].ToString (),
                                                   string.Format ("{0:C}", rdr.GetDecimal ("sum")));
                }
                BalanceTreeStore.AppendValues ("Итого:",
                                               string.Format ("{0:C}", TotalIncome));
                rdr.Close ();

                treeviewBalance.ExpandAll ();

            } catch (Exception ex) {
                QSMain.ErrorMessageWithLog (this, "Не удалось сформировать отчет!", logger, ex);
            }
        }