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', '8js893r90g9c25q37rl03km5s7', '216.73.217.68', '1789334978', '1789334978', '/index.php?XTCsid=d163dd0fc0b54bf3066f85422c77e00a&cat=c12_Music.html')

[XT SQL Error]