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', 'jr6iqemmqavtp0j5qebs7tqj50', '216.73.216.82', '1752529490', '1752529490', '/product_info.php?info=p21_Paper-tablecloth-10-meters.html&XTCsid=f6e58886be8011b1d9a8e232c116cb7a')

[XT SQL Error]