Deleting Data From Database Through JavaFX GUI - jdbc

Question

What I want to be able to do is load my database through a table view select an item and have it deleted into the database. I do not have users entering the id of a particular song so it makes it harder for me to accomplish this. I have the GUI set up and all the code that I have so far.
GUI CODE:
SongContent Code:
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package playmymusic;
import javafx.beans.property.IntegerProperty;
import javafx.beans.property.SimpleIntegerProperty;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;
/**
*
* #author man
*/
public class SongContent
{
private final StringProperty artist;
private final StringProperty title;
private final StringProperty genre;
private final IntegerProperty id;
public SongContent(int id, String artist, String title, String genre)
{
this.artist = new SimpleStringProperty(artist);
this.title = new SimpleStringProperty(title);
this.genre = new SimpleStringProperty(genre);
this.id = new SimpleIntegerProperty(id);
}
public Integer getId()
{
return id.get();
}
public void setID(int paramId)
{
id.set(paramId);
}
public String getArtist()
{
return artist.get();
}
public void setArtist(String paramArtist)
{
artist.set(paramArtist);
}
public String getTitle()
{
return title.get();
}
public void setTitle(String paramTitle)
{
title.set(paramTitle);
}
public String getGenre()
{
return genre.get();
}
public void setGenre(String paramGenre)
{
genre.set(paramGenre);
}
public StringProperty artistProperty(){return artist;}
public StringProperty titleProperty(){return title;}
public StringProperty genreProperty(){return genre;}
public IntegerProperty idProperty() { return id;}
}
Controller Code:
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package playmymusic;
import java.io.IOException;
import java.net.URL;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ResourceBundle;
import javafx.beans.property.IntegerProperty;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.fxml.Initializable;
import javafx.scene.Scene;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.control.TextField;
import javafx.scene.control.cell.PropertyValueFactory;
import javafx.scene.layout.Pane;
import javafx.stage.Stage;
import javax.swing.JOptionPane;
import org.apache.derby.jdbc.ClientDriver;
/**
*
* #author man
*/
public class FXMLDocumentController implements Initializable {
public LoginModel loginModel = new LoginModel();
#FXML
private TextField txtUsername;
#FXML
private TextField txtPassword;
#FXML
private TextField txtArtist;
#FXML
private TextField fxTitle;
#FXML
private TextField fxGenre;
#FXML
private TableView<SongContent> tableView;
#FXML
private TableColumn<SongContent, Integer> id;
#FXML
private TableColumn<SongContent, String> artist;
#FXML
private TableColumn<SongContent, String> title;
#FXML
private TableColumn<SongContent, String> genre;
private ObservableList<SongContent> data;
#FXML
private void Login(ActionEvent event) throws SQLException {
try {
if(loginModel.isLogin(txtUsername.getText(), txtPassword.getText()))
{
Stage primaryStage = new Stage();
FXMLLoader loader = new FXMLLoader();
Pane root = loader.load(getClass().getResource("PopUpWindow.fxml").openStream());
Scene scene = new Scene(root, 785, 809);
primaryStage.setScene(scene);
primaryStage.show();
PlayMyMusic.primaryStage.close();
}else
{
System.out.println("WOOPS");
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
#FXML
private void songs(ActionEvent e) throws SQLException, ClassNotFoundException
{
loginModel.insertSongs(txtArtist.getText(), fxTitle.getText(), fxGenre.getText());
try
{
int i = 1;
Connection conn = DriverManager.getConnection("jdbc:derby://localhost:1527/PlayMyMusicDB;user=test;password=test");
data = FXCollections.observableArrayList();
ResultSet rs = conn.createStatement().executeQuery("select * from Song");
while(rs.next())
{
data.add(new SongContent(rs.getInt(1), rs.getString(2), rs.getString(3), rs.getString(4)));
i++;
}
}catch(SQLException ex) {
System.err.println("Error" + ex);
}
id.setCellValueFactory(new PropertyValueFactory<>("id"));
artist.setCellValueFactory(new PropertyValueFactory<>("artist"));
title.setCellValueFactory(new PropertyValueFactory<>("title"));
genre.setCellValueFactory(new PropertyValueFactory<>("genre"));
tableView.setItems(null);
tableView.setItems(data);
txtArtist.clear();
fxTitle.clear();
fxGenre.clear();
}
#FXML
public void deleteItems(ActionEvent e) throws SQLException, ClassNotFoundException
{
Connection c = DriverManager.getConnection("jdbc:derby://localhost:1527/PlayMyMusicDB;user=test;password=test");
int action = JOptionPane.showConfirmDialog(null, "Are you sure you want to delete this item?");
if(action == 0)
{
try
{
IntegerProperty i = SongContent.idProperty();
ResultSet rs = c.createStatement().executeQuery("DELETE FROM Song where i = " + i);
}catch(Exception e1)
{
e1.printStackTrace();
}
}
}
#Override
public void initialize(URL url, ResourceBundle rb)
{
}
}
`
Any explination of why this could not be deleting my data? I would also love it if someone explained to me a strategy of resetting the SongNumberID every time the GUI opened and closed. But, the main goal for me is to figure out how to delete songs.
Thanks so much
-Aaron

Answer 1

The result of calling toString on a SimpleIntegerProperty is something like IntegerProperty [value: 10]. You should use the value, not the IntegerProperty. Furthermore it's better to use a PreparedStatement to create the query. Also you should get the selected item from the table instead of trying to reference a instance method as if it was static:
SongContent song = tableView.getSelectionModel().getSelectedItem();
if (song != null) {
// there is a selection -> delete
...
PreparedStatement statement = c.prepareStatement("DELETE FROM Song WHERE i = ?");
statement.setInt(1, song.getId());
statement.executeUpdate();
...
}
Furthermore you should make sure i is actually the column name of the id column (and not id).