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', 'cn7c8ovmedsmus1aq21qve7863', '216.73.216.176', '1762431445', '1762431445', '/products_new.php?XTCsid=3547ee950f9337e348e5e07def1466f0')

[XT SQL Error]