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', 'tmap4krfv9g139fu383iekojd5', '3.139.101.107', '1738995289', '1738995289', '/index.php?XTCsid=3ea3bnp0vmbqarg8bfequsbfv5&cat=c158_Werkzeug-Akku.html')

[XT SQL Error]