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', 's74n72n6a8160dc9fdc7jutjv3', '18.208.186.19', '1573774219', '1573774219', '/')

[XT SQL Error]