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', '6bs8cc660khc1163fkemb23r42', '54.174.43.27', '1563352075', '1563352075', '/')

[XT SQL Error]