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', 'nvfeqodakfs2eg8ka31llb6kh2', '216.73.216.141', '1793813809', '1793813809', '/index.php?XTCsid=c63b24e231384cad64f954428cedcfc2&cat=c6_Foodstuffs.html')

[XT SQL Error]