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', '419jt8336uojim8lv90gp12842', '216.73.216.59', '1789223215', '1789223215', '/shop_content.php?XTCsid=cf859f8c520cc195faeaeafdbd8825bf&coID=3')

[XT SQL Error]