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', 't5hausisoq2ejmkhamab6jm7r3', '23.22.240.119', '1516763072', '1516763072', '/')

[XT SQL Error]