1366 - Incorrect integer value: '' for column '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', 'sdqs9iv7e69s6r0eghid8f2rq6', '216.73.216.55', '1794434208', '1794434208', '/product_info.php?XTCsid=a63f52844b6e675f480eaf86612536c2&info=p8_100-Placemats.html')

[XT SQL Error]