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', 'os6ik9bqdh6d6jo397shd48q46', '216.73.217.116', '1786493927', '1786493927', '/index.php?XTCsid=d3aeae78ea7b7e9600a4cc5c86a9a047')

[XT SQL Error]