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', 'akl1aerclqn2p86c8d82r7gmm4', '3.144.6.254', '1738998874', '1738998874', '/index.php?XTCsid=nmu1l7bj1113ksvu525rsptc72&cat=c158_Werkzeug-Akku.html')

[XT SQL Error]