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', '3hipjoeum7mrufc3c72rn1fvu5', '216.73.216.9', '1757996659', '1757996659', '/product_info.php?XTCsid=ec445a26a1be1b54e711876da9fff244&info=p12_1-Rolle-Krepp-Papier.html')

[XT SQL Error]