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', 'lgei0dl6qt3a87s15s17hafc47', '216.73.217.0', '1790130832', '1790130832', '/index.php?XTCsid=38717c4dd62e88001622b2c7b8b8372a&cat=c12_Music.html')

[XT SQL Error]