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', '97dv47t08dm6pmk9bugh6bogi3', '216.73.216.9', '1757928135', '1757928135', '/product_info.php?XTCsid=3547ee950f9337e348e5e07def1466f0&info=p12_33-feet-crape-paper.html')

[XT SQL Error]