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', 'm2svnlg2kkf41dqple7sau0oi7', '52.15.128.81', '1738999521', '1738999521', '/index.php?XTCsid=mkl8qqqorbnshicuaf45rnrdo2&cat=c652_Akku-Packs.html')

[XT SQL Error]