1366 - Incorrect integer value: '' for column 'customer_id' at row 1

insert into whos_online (customer_id, full_name, session_id, ip_address, time_entry, time_last_click, last_page_url) values ('', 'Guest', '0h7kdn5aa6guguk3737bsj7kq5', '216.73.217.128', '1790010226', '1790010226', '/product_info.php?XTCsid=792dd2eece839333bab562194e3fb545&info=p2_Bavarian-Pennant-Chain.html')

[XT SQL Error]