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', '81v13v0qm5iemvotfchqk3put1', '18.117.186.131', '1738997204', '1738997204', '/index.php?XTCsid=c8tsstf8ajiodlgrn3rqsr62b1&cat=c652_Akku-Packs.html')

[XT SQL Error]