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', 'f0ifniu6jmc4lk5pdv5str6gp2', '216.73.216.133', '1762171833', '1762171833', '/index.php?XTCsid=c407ede434192d8d024c7c2f06b2be8c&cat=c13_Accessoires.html')

[XT SQL Error]