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', '04otn46hpotd8onu5d895q11l3', '216.73.216.128', '1763363079', '1763363079', '/index.php?XTCsid=70a397840fb9c4878acc42c508f919de')

[XT SQL Error]