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', 'h0i07q1al6kv1o2ts5ubll89f7', '34.236.190.216', '1566789105', '1566789105', '/')

[XT SQL Error]