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', '48ijrjm2c57hmia06hf3o83h73', '216.73.216.63', '1774422497', '1774422497', '/product_info.php?XTCsid=ca28ab8f46bb6e791b42fe9b92719761&info=p18_Fun-Hat.html')

[XT SQL Error]