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', 'aqhuii7lfs218tfv823cjn6k17', '216.73.216.197', '1751519175', '1751519175', '/product_info.php?info=p7_Girlande-4-m.html&XTCsid=ec445a26a1be1b54e711876da9fff244')

[XT SQL Error]