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', 'u1an4h48br2a19hm3grr0hi0k7', '216.73.216.9', '1757822792', '1757822792', '/product_info.php?XTCsid=6434a50ec6def965fd2bb3c4699fde82&info=p19_10-Paper-Plates.html')

[XT SQL Error]