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', 'ch7i7ajprvdlcjgkcjl5n23qs7', '3.85.92.139', '1561469284', '1561469284', '/product_info.php/info/p29_DTD-Edelstahl-Backplate-3mm.html')

[XT SQL Error]