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', '9tns8etef5eo178vds86rjrf27', '18.223.172.110', '1738998193', '1738998193', '/index.php?XTCsid=mkl8qqqorbnshicuaf45rnrdo2&cat=c21_Handy---Smartphone-Akku.html')

[XT SQL Error]