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', 'b4idshsq7urnq9s0m8mcil4et0', '216.73.216.127', '1752881864', '1752881864', '/index.php?cat=c12_Music.html&XTCsid=81fba26e1f006e30d12d9ee4d58a4030')

[XT SQL Error]