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', 'n32jq0nvajiqfuvar83ejrcsj2', '216.73.216.82', '1752528891', '1752528891', '/shop_content.php?coID=3&XTCsid=ec23ca965190a8290c666be9c9947acd')

[XT SQL Error]