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', 'b21nikvs6mbu1dldmrv987mgf4', '216.73.216.89', '1766330223', '1766330223', '/product_info.php?info=p552_800468-Futterstampfer--Ruebenstoesser.html')

[XT SQL Error]