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', 'v9n1f4glgqm0r1v09pikfv0482', '216.73.216.80', '1751318971', '1751318971', '/shop_content.php?coID=3&XTCsid=f6e58886be8011b1d9a8e232c116cb7a')

[XT SQL Error]