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', '74r737bhc4g0qtagjgi6lhs406', '3.138.101.93', '1738999660', '1738999660', '/index.php?XTCsid=nj57khd41hu8ciniagj0kmvlc3&cat=c918_Makita-10-8Volt-Akku.html')

[XT SQL Error]