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', '59cnikt9s86qq75l1cpngjere7', '13.59.182.74', '1738994015', '1738994015', '/index.php?XTCsid=7o9vvcq8f10964g5j8ia8t32h0&cat=c722_Funk-Kopfh--rer-Akku.html')

[XT SQL Error]