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', 'gtp6bibmn1q9u4nt1k1eq11023', '216.73.217.60', '1780076912', '1780076912', '/index.php?XTCsid=903d490a11e72fb45b2507d2f3478040&cat=c13_Accessoires.html')

[XT SQL Error]