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', 'je499b49kr2p01gpn52305j067', '216.73.216.110', '1752059390', '1752059390', '/product_info.php?info=p12_33-feet-crape-paper.html&XTCsid=0832187515ca706758d8e1ce01e34faf')

[XT SQL Error]