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', '11kisps7b0iikf6te7kavmfl81', '18.97.14.80', '1747165453', '1747165453', '/xtshop/index.php')

[XT SQL Error]