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', 'gebrqqogtdc378hdj74pvqes33', '216.73.216.87', '1765772104', '1765772104', '/product_info.php?XTCsid=792dd2eece839333bab562194e3fb545&info=p9_Paper-Lantern.html')

[XT SQL Error]