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', 'mdfctnk75e7vnmkgitsh948kb4', '216.73.216.197', '1751522534', '1751522534', '/index.php?cat=c13_Accessoires.html&XTCsid=6c2468ca28c6c182aaed37353d32ae32')

[XT SQL Error]