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', 'daa5ed719a859f9035a503a18a2a853a', '35.172.193.238', '1711624476', '1711624476', '/redirect.php?action=product&id=29')

[XT SQL Error]