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', '3vhibh4h7g3l81bg4p4qifa344', '216.73.216.87', '1769300258', '1769300258', '/product_info.php?XTCsid=33509f1bee4ee2cbb673a74e5faae0d4&info=p6_100-Paper-Plates.html')

[XT SQL Error]