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', 'nvq76bhju6i3hdjdbq43ki7mc1', '216.73.216.141', '1751422093', '1751422093', '/index.php?XTCsid=96e5a14b1aa2db44cddf9aa911838531')

[XT SQL Error]