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', 'ff9fad8d4a177b8d1aaf85e98478b373', '3.237.94.109', '1601110081', '1601110081', '/')

[XT SQL Error]