title: linq group by object
body: <p>I have an object which contains a list of another object as follow:</p>
  
  <pre><code>    class cl
      {
        List&lt;a&gt; a ;
        public List&lt;a&gt; listofA
        {
        get; set;
        }
      }
  
      class a
      {
      //other properties
         string comment ;
        public string comment
        {
        get; set;
        }
      }
  </code></pre>
  
  <p>Now how do i make a linq query to see if comment is of some string here is my query:</p>
  
  <pre><code>  var query = (from c in scope.Extent&lt;cl&gt;()
                           where  c.Date &gt;= dateFrom &amp;&amp; c.Date &lt; dateTo
                           &amp;&amp; c.Actions.Where(a =&gt; (a.comment== "") )
                           orderby c.Date.Value.Date
                           group c by c.Date.Value.Date into grpDate
                            select new { grpDate.Key, items = grpDate });
  </code></pre>
  
  <p>but i get error saying :</p>
  
  <pre><code>Error   15  Operator '&amp;&amp;' cannot be applied to operands of type 'bool' and 'System.Collections.Generic.IEnumerable&lt;&gt;
  Error   13  Cannot convert lambda expression to type 'string' because it is not a delegate type 
  </code></pre>