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', '0q03f6upi973ncfu9pf8p4icc2', '216.73.217.1', '1789388567', '1789388567', '/product_info.php?XTCsid=15cbbc13723f7bc63afaf1294f637517&info=p19_10-Paper-Plates.html')

[XT SQL Error]