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', 's0bqa8qppk6h6sl0h3ud6415p7', '216.73.216.9', '1757959375', '1757959375', '/product_info.php?XTCsid=38717c4dd62e88001622b2c7b8b8372a&info=p17_20-Tissue-Napkins.html')

[XT SQL Error]