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', 'm0cmqm7k4ntvda4739k7g3qub1', '216.73.216.9', '1757833783', '1757833783', '/product_info.php?XTCsid=38717c4dd62e88001622b2c7b8b8372a&info=p21_Paper-tablecloth-10-meters.html')

[XT SQL Error]