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', 'c3jv0ti7p4cmj15q8jvbloj2l2', '216.73.217.0', '1790167762', '1790167762', '/products_new.php?XTCsid=792dd2eece839333bab562194e3fb545')

[XT SQL Error]