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', '9h3viue7e2q5o42b2u06vk5ge4', '216.73.216.7', '1758225483', '1758225483', '/shop_content.php?XTCsid=80c3e9fc87b53cb0d288d19ef4e9b63c&coID=2')

[XT SQL Error]