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', 'qoma5o5lo66micn5gb3l7e4l93', '216.73.216.87', '1765766797', '1765766797', '/index.php?XTCsid=02e6bd680443148f6a7ac7cc84f5c4da')

[XT SQL Error]