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', 'q2oqhlpt4fmhn0me7lrt1e8kj4', '216.73.216.130', '1761218018', '1761218018', '/product_info.php?XTCsid=ec445a26a1be1b54e711876da9fff244&info=p19_10-Party-Teller.html')

[XT SQL Error]