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', '5fvp6v9avbnqd3dfm78kuga836', '216.73.216.43', '1769922087', '1769922087', '/index.php?XTCsid=32b49b46b5da115de8e714f9609f9c5b')

[XT SQL Error]