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', '9i665h45nob9hvjpdob4gks3p7', '3.145.34.133', '1738999973', '1738999973', '/index.php?XTCsid=c8tsstf8ajiodlgrn3rqsr62b1&cat=c953_USV-Batterien.html')

[XT SQL Error]