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', '99po936lq5pba6sfaq700bi991', '3.140.253.240', '1738995435', '1738995435', '/index.php?XTCsid=je9k4v12tkp4tisil6f61oiu11&cat=c640_Netzteile.html')

[XT SQL Error]