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', 'sl3aeqnvjk39vso7d7puio5f94', '216.73.216.60', '1760514976', '1760514976', '/product_info.php?XTCsid=80c3e9fc87b53cb0d288d19ef4e9b63c&info=p12_33-feet-crape-paper.html')

[XT SQL Error]