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', 'l7m993utqnjrj7a59jd3pls822', '216.73.216.9', '1758140406', '1758140406', '/index.php?XTCsid=38717c4dd62e88001622b2c7b8b8372a&cat=c2_Decoration.html')

[XT SQL Error]