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', 'sfc7o9ru8l5iqari0ksc52fkk2', '216.73.216.147', '1751741557', '1751741557', '/index.php?cat=c13_Accessoires.html&XTCsid=81fba26e1f006e30d12d9ee4d58a4030')

[XT SQL Error]