1366 - Incorrect integer value: '' for column `CP_as15`.`whos_online`.`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', '5nla3plst3m9mn9491455mr7f3', '3.12.196.93', '1738997069', '1738997069', '/index.php?XTCsid=8e9c41f9ih262sbjeph8l1hut4&cat=c1175_Dremel-Werkzeug-Akku.html')

[XT SQL Error]