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', '41n02drpim8gt0ojd2nf9hbmk7', '216.73.216.147', '1751756479', '1751756479', '/product_info.php?info=p7_Garland-13-feet.html&XTCsid=15cbbc13723f7bc63afaf1294f637517')

[XT SQL Error]