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', 'cv4psvvdg1v8mvrn4bhv8lilo7', '216.73.216.147', '1751594584', '1751594584', '/index.php?cat=c2_Decoration.html&XTCsid=ca28ab8f46bb6e791b42fe9b92719761')

[XT SQL Error]