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', 'rhlgm8p87ds8ft2gkur9gcktk0', '216.73.216.190', '1758172967', '1758172967', '/product_info.php?XTCsid=c407ede434192d8d024c7c2f06b2be8c&info=p12_33-feet-crape-paper.html')

[XT SQL Error]