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', 'anft45chdqqvjr1ulsflun04n5', '3.16.81.94', '1747120346', '1747120346', '/product_info.php?info=p17_800208-Ersatz-Heizspirale-fuer-E-Futterdaempfer-26-Liter.html')

[XT SQL Error]