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', '2gtv1gad25dqi5alk5l18j9m00', '3.142.172.179', '1738998751', '1738998751', '/index.php?XTCsid=c8tsstf8ajiodlgrn3rqsr62b1&cat=c174_Fein-Werkzeug-Akku.html')

[XT SQL Error]