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', 'q5j58vfpt416if396tslgacm83', '216.73.217.89', '1789585305', '1789585305', '/index.php?XTCsid=aab1cbf51f07f7bc38caf30c84028b6c')

[XT SQL Error]