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', 'lv3d7dop9vr76pfbs4iijuc002', '216.73.216.178', '1768627293', '1768627293', '/index.php?XTCsid=3547ee950f9337e348e5e07def1466f0&cat=c2_Decoration.html')

[XT SQL Error]