Linq to XML Noob question - distinct and order by on attributes

Question

I'm just getting started using Linq to XML and I have a simple document with records like this:

<record date="6/27/2002" symbol="DG" price="15.00" />

I want a list of distinct symbols as strings, in order.

This gives me an unordered list of all attributes, but I'm stuck

var query =
  from e in xml.Elements()
  select e.Attribute("symbol");

How can this be modified to give me what I want?

Answer 1

How about:

    var query = (from e in xml.Elements()
                 let symbol = (string)e.Attribute("symbol")
                 where symbol != null
                 orderby symbol
                 select symbol).Distinct();

Answer 2

I'd do that with lambda syntax:

var query = xml.Elements()
               .Select(e => (string)e.Attribute("symbol"))
               .Distinct()
               .OrderBy(x=>x);