public void EditTrading_CorrectData_TrueReturned()
        {
            //Arrange
            int    book_id   = 3;
            string ticket    = "А-1234-21";
            string delivery  = "2004.11.11";
            string reception = "2004.12.11";
            string login     = "******";
            string newTicket = "А-2134-21";
            //Act
            List <trading> updatingTrading = new List <trading>();

            if (tradingController.AddNewTrading(book_id, ticket, Convert.ToDateTime(delivery), Convert.ToDateTime(reception), login))
            {
                int tradingId = dbHelper.context.trading.OrderByDescending(t => t.trading_id).FirstOrDefault().trading_id;
                updatingTrading = tradingController.GetTradingString(tradingId);

                if (tradingController.UpdateTradingInfo(Convert.ToInt32(book_id), newTicket, Convert.ToDateTime(delivery), Convert.ToDateTime(reception), updatingTrading))
                {
                    dbHelper = new DbHelper();
                    string expectedTicket = dbHelper.context.trading.Where(t => t.ticket == newTicket).First().ticket;

                    var selectString = dbHelper.context.trading.OrderByDescending(t => t.trading_id).First().trading_id;
                    tradingController.RemoveTrading(selectString);

                    //Assert
                    Assert.AreEqual(newTicket, expectedTicket);
                }
            }
        }
        /// <summary>
        /// Событие при клике на кнопку "Продолжить"
        /// </summary>
        private void SaveBtn_Click(object sender, RoutedEventArgs e)
        {
            var book = NewBookComboBox.SelectedItem as books;

            if (tradingController.UpdateTradingInfo(Convert.ToInt32(book.book_id.ToString()), NewTicketInput.Text, Convert.ToDateTime(NewDeliveryInput.SelectedDate), Convert.ToDateTime(NewReceptionInput.SelectedDate), updatingTrading))
            {
                SaveBtn.IsEnabled = false;
                MessageBox.Show("Данные успешно обновлены");
                this.NavigationService.Navigate(new MenuLibrarianPage());
            }
            else
            {
                MessageBox.Show("Данные не были обновлены");
            }
        }