title: Get what exists in one DataTable but not another using LINQ
body: <p>I have two <code>DataTable</code>s. I want to get what exists in the first one but does not exist in the second one. I would like the results in another <code>DataTable</code>. I would like to use LINQ.</p>
  
  <ul>
  <li>The First datatable:</li>
  </ul>
  
  <hr>
  
  <pre><code>DataTable dt1 = cc1roleDAL.GetAll(x, 0);
  </code></pre>
  
  <ul>
  <li>The second datatable:</li>
  </ul>
  
  <hr>
  
  <pre><code>DataTable dt2 = cc1roleDAL.GetSpecific(x);
  </code></pre>
  
  <blockquote>
    <p>Note: the column names I return from the the two datatables: </p>
  </blockquote>
  
  <ol>
  <li><p><code>crs_name</code></p></li>
  <li><p><code>name</code></p></li>
  </ol>