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', 'abtig3e0e95c8o2edubj3a6m07', '18.119.255.225', '1738994639', '1738994639', '/index.php?XTCsid=mgdqk1fhm8rf8rhaciivk3tpt2&cat=c639_Akkus.html')

[XT SQL Error]