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', '77d238eaabeeed18bd52181aefd041a7', '34.200.218.187', '1597048451', '1597048451', '/')

[XT SQL Error]