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', '9i3dthj6jcqu1kku1peohm8e57', '216.73.216.9', '1758207255', '1758207255', '/product_info.php?XTCsid=33509f1bee4ee2cbb673a74e5faae0d4&info=p5_Large-Garland-33-feet.html')

[XT SQL Error]