private void FindCustomerButton_OnClick(object sender, RoutedEventArgs e) { string name = SearchCustomerNameTextBox.Text; string firstName = SearchCustomerFirstNameTextBox.Text; string phoneNumber = SearchCustomerPhoneNumberTextBox.Text; if (!FieldsCompleted(name, firstName, phoneNumber)) { SearchDisplayInfoTextBlock.Text = @"Must complete mandatory fields"; } else { FindCustomerButton.IsEnabled = true; var client = _client.FindCustomer(name, firstName, phoneNumber); if (client == null) { SearchDisplayInfoTextBlock.Text = @"There is no customer with these specification."; } else { SearchDisplayInfoTextBlock.Text = @"Customer cars are displayed bellow."; string getChassis = "SELECT * FROM Sasiuri"; ExecuteQuery(getChassis, DisplayChassisDataGrid); string getClientCars = $"SELECT * FROM Automobile WHERE ClientId = {client.Id}"; ExecuteQuery(getClientCars, SearchCustomerDataGrid); } } }