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', '3fo7vejcvrq59aepvqropurg76', '216.73.216.130', '1761121187', '1761121187', '/product_info.php?XTCsid=75dc59d6a30660e0992222d2318ca53e&info=p19_10-Paper-Plates.html')

[XT SQL Error]