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', '6jiu077pj22uemibf2d5br3442', '216.73.216.87', '1765788566', '1765788566', '/product_info.php?XTCsid=ca28ab8f46bb6e791b42fe9b92719761&info=p19_10-Paper-Plates.html')

[XT SQL Error]