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', '9odf33755fkr711qh4fapqqh87', '216.73.216.43', '1783409325', '1783409325', '/shop_content.php?XTCsid=1ce6d0a6925740e42ccf6986944a240a&coID=3')

[XT SQL Error]