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', 'j3pijp90g2jpt5b2l9rhr0b593', '216.73.216.130', '1761172712', '1761172712', '/index.php?XTCsid=363052f8eb28c495db1ddeca225278d6&cat=c12_Music.html')

[XT SQL Error]