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', 'jls4bgajcn7i69inldl3117ip2', '3.22.217.60', '1738998823', '1738998823', '/index.php?XTCsid=3d3p3k0ohp8dmvm3fuo7su5ts5&cat=c28_MP3-Player-Akku.html')

[XT SQL Error]