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', 'cekelhir2j9nq79j59ng466d86', '54.162.44.105', '1495549987', '1495549987', '/')

[XT SQL Error]