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', 'ek6kte4cnbee33bk2qok7obds2', '35.172.195.49', '1574453025', '1574453025', '/')

[XT SQL Error]