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', '45ulf5si4v83oqn2ap2v7ojpi3', '216.73.216.122', '1767819677', '1767819677', '/product_info.php?XTCsid=c5d9d9a5780af7d5707e3b2046ece3fe&info=p2_Bavarian-Pennant-Chain.html')

[XT SQL Error]