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', '33980b6228e4d38bfe361e22b4cb2964', '50.17.63.57', '1711686850', '1711686850', '/product_info.php/info/p17_Kastanie-Bluetenhonig.html')

[XT SQL Error]