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', '63juql3ivqooj0ahi3fbdpn2m7', '216.73.216.7', '1758243375', '1758243375', '/product_info.php?XTCsid=502c4d4f7753d1888d9a6ca985d5c9c9&info=p19_10-Paper-Plates.html')

[XT SQL Error]