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', '5pvl5kfu5qesotrov96svt6a14', '216.73.216.147', '1751742377', '1751742377', '/shop_content.php?coID=2&XTCsid=a63f52844b6e675f480eaf86612536c2')

[XT SQL Error]