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', '630e415umunf94st3o0ltnrp41', '216.73.216.130', '1760779514', '1760779514', '/index.php?XTCsid=33509f1bee4ee2cbb673a74e5faae0d4&cat=c5_Crockery.html')

[XT SQL Error]