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', 'k2cc5o197948j1e4d303uphmn3', '216.73.216.180', '1767268495', '1767268495', '/product_info.php?XTCsid=85f438a686cbfb5e3ea5e5d6b9611958&info=p12_33-feet-crape-paper.html')

[XT SQL Error]