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', 'g734ui8ji29nj6lb4s7htp7ep4', '3.144.21.68', '1739000039', '1739000039', '/index.php?XTCsid=b08vstu7leg8ef8i43caoskln6&cat=c1140_Zahlungsterminal-Akkus.html')

[XT SQL Error]