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', 'g5l2ta9lfc51jphg5acauvkdq3', '216.73.216.176', '1762337119', '1762337119', '/index.php?XTCsid=792dd2eece839333bab562194e3fb545&cat=c5_Crockery.html')

[XT SQL Error]