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', 'kcp2d3e8ssh4oa55c07j8llsb3', '216.73.216.165', '1752393617', '1752393617', '/index.php?cat=c13_Accessoires.html&XTCsid=72205775904d1a5c41b590dd7b5ff1d6')

[XT SQL Error]