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', 't6lb53uu4906gb7ec1ls4dtnn7', '216.73.216.110', '1752043774', '1752043774', '/index.php?XTCsid=7da72f1737c0cce1944c3631fc48aa29')

[XT SQL Error]