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', 'ejf9gqcheqgc1vvpbqscs9an54', '216.73.216.130', '1760856572', '1760856572', '/index.php?XTCsid=aab1cbf51f07f7bc38caf30c84028b6c')

[XT SQL Error]