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', '0inminueaad6firtbhojj3kbj1', '3.143.241.104', '1738997498', '1738997498', '/index.php?XTCsid=c8tsstf8ajiodlgrn3rqsr62b1&cat=c640_Netzteile.html')

[XT SQL Error]