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', 'ht5gf3vtu6hj9tf95t4b6novr1', '216.73.216.118', '1761707427', '1761707427', '/index.php?XTCsid=0cd933f5b9e21278dcca0c344c19a414')

[XT SQL Error]