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', 'f3aeori72tna9ki5p46rv5r2a6', '54.158.248.167', '1506273729', '1506273729', '/')

[XT SQL Error]