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', '52fmg997fsilsjhs0sg8gucjs6', '18.218.43.201', '1739000967', '1739000967', '/index.php?XTCsid=u26kusssenv9nf8n7cr2rtvfn3&cat=c31_Batterien.html')

[XT SQL Error]