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', 'eame7pcf20o5kpqp2bh2p87ve5', '216.73.216.60', '1760635588', '1760635588', '/products_new.php?XTCsid=ec5c494959fcca91c837d8ac4294232c')

[XT SQL Error]