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', '07j87h1fv14koucdr393upc7d0', '3.15.226.174', '1738995321', '1738995321', '/index.php?XTCsid=3ea3bnp0vmbqarg8bfequsbfv5&cat=c866_Mobile-Drucker-Akkus.html')

[XT SQL Error]