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', '8e9b5dad1bad5a7358a7780aea55aefa', '44.192.75.131', '1711677830', '1711677830', '/index.php')

[XT SQL Error]