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', 'vthllu9g563srbevuui61te8f5', '18.117.138.39', '1738999779', '1738999779', '/index.php?XTCsid=c8tsstf8ajiodlgrn3rqsr62b1&cat=c23_Camcorder-Akku.html')

[XT SQL Error]