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', '5mjmgk4cm77jguf1355jvfhnk7', '216.73.217.152', '1791003035', '1791003035', '/shop_content.php?XTCsid=85f438a686cbfb5e3ea5e5d6b9611958&coID=3')

[XT SQL Error]