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', 's83dus2v5pv5p7kb28vnt9ube7', '216.73.216.9', '1757958247', '1757958247', '/shop_content.php?XTCsid=cf859f8c520cc195faeaeafdbd8825bf&coID=3')

[XT SQL Error]