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', 'abnckjbjq1grten3no5dr653h6', '18.206.16.123', '1569191142', '1569191142', '/')

[XT SQL Error]