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', '93f2p7k4un3u4hlusgmd9rf175', '216.73.216.130', '1760765567', '1760765567', '/product_info.php?XTCsid=38f09672db884903e3803adf9d076819&info=p13_Deco-ball.html')

[XT SQL Error]