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', 'dibi8r0ip5fkgu1uhs4b0ts4p7', '216.73.216.151', '1789700199', '1789700199', '/index.php?XTCsid=a63f52844b6e675f480eaf86612536c2&cat=c5_Crockery.html')

[XT SQL Error]