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', '5ghc9t0d9cdseev4j5fsj439p4', '216.73.217.172', '1790515077', '1790515077', '/index.php?XTCsid=a63f52844b6e675f480eaf86612536c2&cat=c13_Accessoires.html')

[XT SQL Error]