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', 'gk3r9d3g1j33g85de4isns7qt4', '216.73.217.120', '1793705959', '1793705959', '/product_info.php?XTCsid=7c604026da355cfd6a094c68b431572d&info=p9_Paper-Lantern.html')

[XT SQL Error]