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', 'jt5qigl36div8m2oilpehpv8a3', '216.73.216.9', '1758173653', '1758173653', '/')

[XT SQL Error]