1366 - Incorrect integer value: '' for column `hbl_shop`.`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', 'gu7kbof26uhfb8kfvfkkto0rt0', '216.73.216.217', '1751516919', '1751516919', '/product_info.php?info=p510_Flugmischung-fuer-Turbo--Meister-25kg-LTM.html')

[XT SQL Error]