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', 'vn1091uag725bp9qsf7oa33eb7', '216.73.216.180', '1766024162', '1766024162', '/product_info.php?XTCsid=7f3d063595fd0cf7dd24ecea4b1409d6&info=p6_100-Paper-Plates.html')

[XT SQL Error]