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', '09r4bcdt349fbe16gpec0bdmv5', '216.73.216.118', '1761668468', '1761668468', '/product_info.php?XTCsid=3dfedf8e10ab51b65faa7b7d7332d93a&info=p18_Fun-Hat.html')

[XT SQL Error]