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', 'o919965g77qsep585qqgou9qm6', '216.73.216.244', '1752215808', '1752215808', '/product_info.php?info=p7_Garland-13-feet.html&XTCsid=3547ee950f9337e348e5e07def1466f0')

[XT SQL Error]