There should be no other host. The mysql host refers to the location of MySQL on the server that your site is on. Localhost will automatically use the server that you are on. If your site is displaying the demo items, those items are in the database already so your site is accessing the database and it is showing everything there properly.
Items not showin up when saved does not sound like a MySQL issue, it sounds that a software issue. MySQL is only the place that information is stored, it is not in charge of putting that information there, the php application does that.
Perhaps there is a bug in the shopping cart software that you are using. Does it give you any errors?