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', '87cqbbvqga5ho3ifp6sgr06hv4', '216.73.216.180', '1767381392', '1767381392', '/index.php?XTCsid=38717c4dd62e88001622b2c7b8b8372a&cat=c8_Disposable-tableware.html')

[XT SQL Error]