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', '35rhurjgar5dfhcbds6hr16463', '216.73.216.197', '1751518064', '1751518064', '/index.php?XTCsid=25107e022e57904016ff1d84720d2d85')

[XT SQL Error]