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', 'do3r9kvoilipa4516gcpp5pgp5', '216.73.216.82', '1752530402', '1752530402', '/product_info.php?info=p15_25-balloons.html&XTCsid=ec23ca965190a8290c666be9c9947acd')

[XT SQL Error]