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', 'crn6p79nho4klh5bfcp80bfln2', '3.235.75.174', '1591338648', '1591338648', '/')

[XT SQL Error]