Help needed with updating mysql database

[SilentCodingOne]

I have an application that is designed to manage the flights for an airline. I'm trying to store the flight info in a mysql database. I'm able to establish a connection to the database and send the info from my GUI to the appropriate method to add flight, delete flight, and search for a flight. I have tried a number of things and I must be doing something wrong because it is not working. I was getting a null pointer exception which I have corrected via the updated code below in the 2nd code block. However the records on the database are still not updating. Any help would be appreciated.

Thanks

import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.color.*;
import java.io.*;
import java.util.*;
import java.text.*;
import javax.swing.border.*;
import java.sql.*;
import javax.swing.*;

public class FlightManager extends JFrame implements ActionListener{
    
    // JDBC driver name and database url
    static final String DRIVER = "com.mysql.jdbc.Driver";
    static final String DATABASE_URL = "jdbc:mysql://localhost:3306/flightmanager";
    // jtextfield components
    private JTextField fn = new JTextField(15);
    private JTextField oc  = new JTextField(15);
    private JTextField dc = new JTextField(15);
    private JTextField dt = new JTextField(15);
    // labels telling user what each jtextfield is for
    private JLabel fnl = new JLabel("Flight Number: ");
    private JLabel ocl = new JLabel("City of Origin: ");
    private JLabel dcl = new JLabel("Destination City: ");
    private JLabel dtl = new JLabel("Departure Time: ");
    // variables that hold data added to jtextfield
    private int flightNum;
    private String originCity;
    private String destinationCity;
    private String departure;
    //  jbutton components
    private JButton add;
    private JButton remove;
    private JButton search;
    private JButton exit;
    private DatabaseUpdate du = new DatabaseUpdate();
    
    public static void main(String[] args) throws SQLException {
        
        try {
            
            Connection connection = null;
            Statement statement = null;
            ResultSet resultSet = null;
            
            Class.forName(DRIVER);
            connection = DriverManager.getConnection(DATABASE_URL, "root", "lilly");
            
            
        } catch (ClassNotFoundException ex) {
            ex.printStackTrace();
        }
        
        FlightManager fm = new FlightManager();
        Container pc = new Container();
        pc.setLayout(new BoxLayout(pc, BoxLayout.Y_AXIS));
        JPanel blank = new JPanel();
        pc.add(blank);
        pc.add(fm.getFlightInputPanel());
        pc.add(fm.getOriginPanel());
        pc.add(fm.getDestinationPanel());
        pc.add(fm.getDepartureTimePanel());
        
        JFrame f = new JFrame();
        f.setTitle("Flight Manager");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.add(pc, "First");
        f.add(fm.getButtonPanel(), "Last"); // adds button panel to JFrame
        f.setSize(500, 200);
        f.setLocation(200,200);
        f.setVisible(true);
        
        
        
    }
    
    private JPanel getFlightInputPanel(){
        FlowLayout flightInputLayout = new FlowLayout(FlowLayout.CENTER);
        JPanel fnp = new JPanel();
        fnp.add(fnl);
        fnp.add(fn);
        
        return fnp;
    }
    
    private JPanel getOriginPanel(){
        FlowLayout flightInputLayout = new FlowLayout(FlowLayout.CENTER);
        JPanel ocp = new JPanel();
        ocp.add(ocl);
        ocp.add(oc);
        
        return ocp;
    }
    
    private JPanel getDestinationPanel(){
        FlowLayout flightInputLayout = new FlowLayout(FlowLayout.CENTER);
        JPanel dcp = new JPanel();
        dcp.add(dcl);
        dcp.add(dc);
        
        return dcp;
    }
    
    private JPanel getDepartureTimePanel(){
        FlowLayout flightInputLayout = new FlowLayout(FlowLayout.CENTER);
        JPanel dtp = new JPanel();
        dtp.add(dtl);
        dtp.add(dt);
        
        return dtp;
    }
    
    private JPanel getButtonPanel(){
        
        FlowLayout buttonLayout = new FlowLayout(FlowLayout.CENTER);
        JPanel buttonPanel = new JPanel();
        add = new JButton("Add Flight");
        add.addActionListener(this);
        remove = new JButton("Delete Flight");
        remove.addActionListener(this);
        search = new JButton("Search For Flight");
        search.addActionListener(this);
        exit = new JButton("Exit");
        exit.addActionListener(this);
        buttonPanel.add(add);
        buttonPanel.add(remove);
        buttonPanel.add(search);
        buttonPanel.add(exit);
        
        return buttonPanel;
    }
    
    
    // processes actions for when buttons are pushed
    public void actionPerformed(ActionEvent e) {
        
        Object ac = e.getSource();
        
        // action to take if add flight button is pushed
        if(ac == add){
            
            flightNum = Integer.parseInt(fn.getText());
            originCity = oc.getText();
            destinationCity = dc.getText();
            departure = dt.getText();
            
            du.addFlight(flightNum, originCity, destinationCity, departure);
            
            // clears out current contents of JTextFields
            fn.setText("");
            oc.setText("");
            dc.setText("");
            dt.setText("");
            
        }
        // action to take if search for flight is pushed
        if(ac == search){
         
            originCity = oc.getText();
            destinationCity = dc.getText();

            du.searchFlight(originCity, destinationCity);
            
            oc.setText("");
            dc.setText("");
        }
        
        if(ac == remove){
        
            flightNum = Integer.parseInt(fn.getText());
            originCity = oc.getText();
            destinationCity = dc.getText();
            departure = dt.getText();
            
            du.removeFlight(flightNum, originCity, destinationCity, departure);
        }
        
        
        // action to take if exit button is pushed
        if(ac == exit){
            System.exit(0);
        }
    }
}

import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.color.*;
import java.io.*;
import java.util.*;
import java.text.*;
import javax.swing.border.*;
import java.sql.*;
import javax.swing.*;

public class DatabaseUpdate {
    
    // JDBC driver name and database url
    static final String DRIVER = "com.mysql.jdbc.Driver";
    static final String DATABASE_URL = "jdbc:mysql://localhost:3306/flightmanager";
     Connection connection = null;
     Statement statement = null;
     ResultSet resultSet = null;
    
    public DatabaseUpdate(){

        try {
            
                    
            Class.forName(DRIVER);
            connection = DriverManager.getConnection(DATABASE_URL, "root", "lilly");
            
            
        } catch (ClassNotFoundException ex) {
            ex.printStackTrace();
        }catch (SQLException s){
            System.out.println("SQL statement is not executed!");
        }
        
    }

    public void addFlight(int flightNum, String originCity, String destinationCity, String departure) {
        
        int flight = flightNum;
        String origin = originCity;
        String destination = destinationCity;
        String departTime = departure;
        
        try{
     
      statement = connection.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_UPDATABLE);
      connection.setAutoCommit(false);
      statement.addBatch("INSERT INTO flightinfo(flightnumber, origincity, destinationcity, departuretime) VALUES(flight, 'origincity', 'destinationcity', 'departuretime')");
      int[] updateCounts = statement.executeBatch();
      connection.commit();

      resultSet = statement.executeQuery("SELECT * FROM flightinfo");

      }
        catch (SQLException s){
        System.out.println("SQL statement is not executed!");
      }
   
            }

   public void removeFlight(int flightNum, String originCity, String destinationCity, String departure) {
        
       int flight = flightNum;
        String origin = originCity;
        String destination = destinationCity;
        String departTime = departure;
        
        try{
        statement = connection.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_UPDATABLE);
     connection.setAutoCommit(false); 
     statement.addBatch("DELETE FROM flightinfo WHERE FlightNumber = 'flight'");  
     int[] updateCounts = statement.executeBatch();
      connection.commit();

//     String sql = "DELETE FROM flightinfo WHERE FlightNumber = flight";
//     int delete = statement.executeUpdate(sql);
//     if(delete == 1){
       System.out.println("Row is deleted.");
//     }
//        else{
//          System.out.println("Row is not deleted.");
//        }
      }
      catch (SQLException s){
        System.out.println("SQL statement is not executed!");
      }
        
    }

    void searchFlight(String originCity, String destinationCity) {
        
        String origin = originCity;
        String destination = destinationCity;
        
        try{
                          
        
      }catch (SQLException s){
        System.out.println("SQL statement is not executed!");
      }
    }
}

[SilentCodingOne]

Everyone can disregard as I was finally able to resolve all issues