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', 'ja2ptbrbnjil385u80cv6o2l04', '54.205.15.219', '1490898406', '1490898406', '/')

[XT SQL Error]