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', 's7d5f1inp4i1tsfcjsud3gsdr7', '54.209.227.199', '1560979713', '1560979713', '/')

[XT SQL Error]