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', 'c6eiust0kjo8576tm6gkcu8ds0', '216.73.216.109', '1774916199', '1774916199', '/product_info.php?XTCsid=3547ee950f9337e348e5e07def1466f0&info=p7_Garland-13-feet.html')

[XT SQL Error]