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', 'l353cu6kgf1q9kipc8g3sqs5h0', '216.73.216.170', '1762094369', '1762094369', '/shop_content.php?XTCsid=38717c4dd62e88001622b2c7b8b8372a&coID=2')

[XT SQL Error]