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', '2c5ji63cq4s9sghuodiac82ju4', '216.73.216.80', '1751326852', '1751326852', '/products_new.php?XTCsid=33509f1bee4ee2cbb673a74e5faae0d4')

[XT SQL Error]