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', '1djc9far539ge0r9pnq492rs45', '3.145.2.158', '1738994970', '1738994970', '/index.php?XTCsid=qi1463dp261ivpfjuiqmhrofh5&cat=c953_USV-Batterien.html')

[XT SQL Error]