using System;
using System.Collections.Generic;
using System.Text;
using System.Xml;
using System.Xml.Linq;

namespace ConsoleApplication5
{
    class Program
    {
        static void Main(string[] args)
        {
            XDocument test = XDocument.Load(dataPath + "c:\\test.xml");
            var result = new XElement("dbs", from test.Descendants("dbs") select new XElement("db", a.Element("id").Value));
            Console.WriteLine(result);
        }
    }
}

XDocument test = XDocument.Load(dataPath + "c:\\test.xml");
            var result =  new XElement("a", from a in test.Descendants("dbs") select new XElement("db", a.Element("id").Value));