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', 'vo6fnaboml6hg0laufukq4e3d6', '216.73.216.87', '1765628587', '1765628587', '/shop_content.php?coID=7%3E%3Cfont+face%3D')

[XT SQL Error]