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', 'm65dunc4jsj5dqmv553m6nrpm6', '216.73.216.82', '1752525500', '1752525500', '/index.php?cat=c12_Music.html&XTCsid=7c604026da355cfd6a094c68b431572d')

[XT SQL Error]