CODING FOR ADD BUTTON
private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {
    try
    {
        Class.forName("com.mysql.jdbc.Driver");
        Connection con = (Connection)DriverManager.getConnection("jdbc:mysql://localhost:3306/conn", "root", "");
        Statement stmt = (Statement)con.createStatement();
        int id = Integer.parseInt(jTextField1.getText());
        String name = jTextField2.getText();
        String pref = (String)jComboBox1.getSelectedItem();
        int age = Integer.parseInt(jTextField3.getText());
        String query = "Insert into conn values("+ id + ", '" + name + "', '" + pref + "', " + age + ");";
        JOptionPane.showMessageDialog(rootPane, "New member added");

        stmt.executeUpdate(query);
    }
    catch (Exception e)
    {
        JOptionPane.showMessageDialog(rootPane, e.getMessage());
    }
    }