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', 'qebrqi8d1mqesfnsar1q554bf0', '216.73.216.180', '1766537664', '1766537664', '/index.php?XTCsid=3dfedf8e10ab51b65faa7b7d7332d93a&cat=c12_Music.html')

[XT SQL Error]