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', 'r17q30fdogfasl4afsp8i10kn3', '107.22.127.78', '1493221043', '1493221043', '/create_account.php')

[XT SQL Error]