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', '0d32m8rf649f4kbe120bpr14k2', '216.73.216.141', '1751426475', '1751426475', '/product_info.php?info=p14_65-drinking-cups-1-2-Liter.html&XTCsid=159458ffcd70853368c82c29206c1527')

[XT SQL Error]