SQLite net PCL - Simple select

I use SQLite from windows app and now I am developing in Xamarin a portable app so I am using the plugin sqlite net pcl and I am having great trouble to understand how it works.

I have a table that is created by te following:

public class Config
    {
        public string IP { get; set; }
        [SQLite.Net.Attributes.Default(true, "Client 2")]
        public string ID { get; set; }
    }

and to create the table:

db.CreateTable<Model.Config>();

Problem: Now I want to select the value in ID column and I do the following:

List<string> hhid = db.Query<string>("select ID from Config",null);

I get this exception: "Object reference not set to an instance of an object"

How can I make a simple select to find this field?

Thanks for any tip