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', 'hjss5b2rmg3nglva3rh1c913q7', '216.73.216.130', '1761169908', '1761169908', '/product_info.php?XTCsid=ec445a26a1be1b54e711876da9fff244&info=p18_Spa--Hut.html')

[XT SQL Error]