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', '6472papmg41k3on6t5cfvkbak5', '216.73.216.89', '1766434268', '1766434268', '/product_info.php?info=p640_806361-Ersatzheizstab-fuer-Bruehkessel--6-kW.html')

[XT SQL Error]