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', '262fntitd6q3j0lj6sk23i2452', '18.116.85.127', '1738996151', '1738996151', '/index.php?XTCsid=mgdqk1fhm8rf8rhaciivk3tpt2&cat=c652_Akku-Packs.html')

[XT SQL Error]