title: Query rows and include rows with columns reversed
body: <p>I'm trying to query a table. I want the results to include the <code>FROM</code> and <code>TO</code> columns, but then also include rows with these two values reversed. And then I want to eliminate all duplicates. (A duplicate is the same two cities in the same order.)</p>
  <p>For example, given this data.</p>
  <h2>Trips</h2>
  <pre><code>FROM                 TO
  -------------------- --------------------
  West Jordan          Taylorsville
  Salt Lake City       Ogden
  West Jordan          Taylorsville
  Sandy                South Jordan
  Taylorsville         West Jordan
  </code></pre>
  <p>I would want the following results.</p>
  <pre><code>West Jordan          Taylorsville
  Taylorsville         West Jordan
  Salt Lake City       Ogden
  Ogden                Salt Lake City
  Sandy                South Jordan
  South Jordan         Sandy
  </code></pre>
  <p>I want to do this using C# and Entity Framework, but I could use raw SQL if I need to.</p>
  <p>Is it possible to do this in a query, or do I need to manually perform some of this logic?</p>