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', '2kmh78oobii8m406flu23feai7', '3.137.217.235', '1738995506', '1738995506', '/index.php?XTCsid=3ea3bnp0vmbqarg8bfequsbfv5&cat=c1194_Makita-4-8Volt-Akku.html')

[XT SQL Error]