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', 'qitupk14ca10k3m24vhe98is11', '216.73.216.147', '1751839483', '1751839483', '/index.php?XTCsid=78d104da211603518fe01de887166f28')

[XT SQL Error]