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', 'g3v0623d0nbc23omgoscd9tkt7', '216.73.216.110', '1752059480', '1752059480', '/index.php?cat=c2_Decoration.html&XTCsid=69a1e06b1d537d651878c63fe4ee3fec')

[XT SQL Error]