Why is my JButton unclickable?

The JButton addItem is not responding to being clicked. I have tried addItem.setEnabled(true); which did not work.

Here is my class:

package com.duckblade.inventory.teller;

import javax.swing.*;
import javax.swing.table.AbstractTableModel;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.sql.SQLException;

public class DatabaseFrame extends JFrame {

    DatabaseFrame f = this;
    Object[][] data;

    public DatabaseFrame(String ip, final String name){
        super(name + "@" + ip);
        try {
            data = Main.dbc.getAll();
            JTable table = new JTable(new AbstractTableModel(){
                String[] names = {"Item ID", "Name", "Quantity", "Profit"};
                public int getRowCount() {
                    return data.length;
                }
                public String getColumnName(int col) {
                    return names[col];
                }
                public int getColumnCount() {
                    return names.length;
                }
                public boolean isCellEditable(int row, int col) {
                    return col!=0 && col!=3;
                }
                public Object getValueAt(int row, int col) {
                    return data[row][col];
                }
                public void setValueAt(Object value, int row, int col){
                    try{
                        Main.dbc.updateItem(Integer.parseInt(getValueAt(row, 0).toString()), getValueAt(row, 1).toString(), Integer.parseInt(getValueAt(row, 2).toString()));
                    }catch (Exception e){
                        JOptionPane.showMessageDialog(f, "An error occurred: " + e.getMessage());
                    }
                }
            });
            add(table.getTableHeader(), BorderLayout.PAGE_START);
            JScrollPane pane = new JScrollPane(table);
            table.setFillsViewportHeight(true);
            add(pane, BorderLayout.CENTER);
            JButton addItem = new JButton("Add Item");
            addItem.addActionListener(new ActionListener() {
                public void actionPerformed(ActionEvent e) {
                    try {
                        int itemId = Integer.parseInt(JOptionPane.showInputDialog("Please enter an item id: "));
                        String itemName = JOptionPane.showInputDialog("Please enter the item name: ");
                        int itemPrice = Integer.parseInt(JOptionPane.showInputDialog("Please enter an item price: "));
                        int itemQuantity = Integer.parseInt(JOptionPane.showInputDialog("Please enter the quantity owned: "));
                        Main.dbc.insertItem(itemId, itemName, itemPrice, itemQuantity);
                        data = Main.dbc.getAll();
                    } catch (Exception ex) {
                        JOptionPane.showMessageDialog(f, "An error occurred: " + ex.getMessage());
                    }
                }
            });
            add(addItem, BorderLayout.SOUTH);
        } catch (SQLException e) {
            JOptionPane.showMessageDialog(Main.f, "Could not retrieve data from database: " + e.getMessage());
            return;
        }
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        setSize(400, 400);
        setVisible(true);
    }

}