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', 'bl4berlpa7ipdajuntpt9qe9d4', '54.236.62.49', '1614459880', '1614459880', '/')

[XT SQL Error]