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', 'rcjd8aukt04kp9ac3bbmpb75l0', '216.73.216.141', '1751420673', '1751420673', '/index.php?cat=c13_Accessoires.html&XTCsid=38f09672db884903e3803adf9d076819')

[XT SQL Error]