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', 'mgldbk3gk2gvdgq2akivl3jfg7', '216.73.216.80', '1751323521', '1751323521', '/index.php?cat=c8_Disposable-tableware.html&XTCsid=0832187515ca706758d8e1ce01e34faf')

[XT SQL Error]