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', 'dbsvph1bknd9nmimpk474817i3', '216.73.216.244', '1782364251', '1782364251', '/product_info.php?XTCsid=cdfc0f2ea8be6cebe1f6056b0a37d83f&info=p19_10-Paper-Plates.html')

[XT SQL Error]