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', 'nop1unm62tnd85tcmv8htp31p2', '216.73.216.7', '1758248619', '1758248619', '/shop_content.php?XTCsid=07630e5b15e9155d8246af3ee660ca0e&coID=7')

[XT SQL Error]