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', '2292b6cbad6227e7d63eafb8d2bdc326', '216.73.216.190', '1776276215', '1776276215', '/shop/index.php?cat=c18_.html')

[XT SQL Error]