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', '4uv50814cg1ao0ijqvbisgf5g1', '216.73.216.141', '1751420673', '1751420673', '/product_info.php?info=p7_Garland-13-feet.html&XTCsid=33509f1bee4ee2cbb673a74e5faae0d4')

[XT SQL Error]