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', 'v86d7mdsj3hhv4kh6i9m94l5k1', '54.226.30.186', '1561368828', '1561368828', '/')

[XT SQL Error]