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', '131m3u4s5c0hhmc03c2b1025q1', '18.206.175.155', '1550456435', '1550456435', '/')

[XT SQL Error]