private async void save(object sender, EventArgs e) { bool change = false; string parameters = ""; if (brandTextbox.Text != car.brand) { change = true; car.brand = brandTextbox.Text; parameters += "brand='" + car.brand + "'"; } if (modelTextbox.Text != car.model) { if (change) { parameters += " , "; } car.model = modelTextbox.Text; parameters += "model='" + car.model + "'"; change = true; } if ((CarType)typeCombobox.SelectedItem != car.type) { if (change) { parameters += " , "; } car.type = (CarType)typeCombobox.SelectedItem; parameters += "type='" + (int)car.type + "'"; change = true; } if (odometerTextbox.Value != car.vehicleOdometer) { if (change) { parameters += " , "; } car.vehicleOdometer = (int)odometerTextbox.Value; parameters += "odometer='" + car.vehicleOdometer + "'"; change = true; } if (registrationNumberTextbox.Text != car.registrationNumber) { if (change) { parameters += " , "; } car.registrationNumber = registrationNumberTextbox.Text; parameters += "registrationNumber='" + car.registrationNumber + "'"; change = true; } if (efficiencyCheckbox.Checked != car.carEfficiency) { if (change) { parameters += " , "; } car.carEfficiency = efficiencyCheckbox.Checked; parameters += "efficiency=" + car.carEfficiency; change = true; } if (isDisabledCheckbox.Checked != car.isDisabled) { if (change) { parameters += " , "; } car.isDisabled = isDisabledCheckbox.Checked; parameters += "isDisabled=" + car.isDisabled; change = true; } if (imageUrlTextBox.Text != car.imageUrl) { if (change) { parameters += " , "; } car.imageUrl = imageUrlTextBox.Text; parameters += "imageUrl='" + car.imageUrl + "'"; change = true; } if (change) { string query = "UPDATE wypozyczalniaSamochody SET " + parameters + " WHERE id =" + car.carId; await DatabaseService.makeQuery(query).ContinueWith(task => { bool result = task.Result; if (result) { MessageBox.Show("Zapisano zmiany."); if (InvokeRequired) { Invoke(new Action(() => { Hide(); })); } else { Hide(); } } else { MessageBox.Show("Nie zapisano zmian."); } }); } }