title: Add additional WHERE clause to existing Linq query
body: <p>I have a method which accepts a linq query:</p>
  
  <pre><code> public IEnumerable&lt;User&gt; GetAll(System.Linq.Expressions.Expression&lt;Func&lt;UserDTO, bool&gt;&gt; query)
   {
       return GetAllDTO(query);
   }
  </code></pre>
  
  <p>What I would like to be able to do is append an additional WHERE clause to this existing query so it looks something like this:</p>
  
  <pre><code> public IEnumerable&lt;User&gt; GetAll(System.Linq.Expressions.Expression&lt;Func&lt;UserDTO, bool&gt;&gt; query)
   {
      return GetAllDTO(query).Where(x =&gt; x.Organisation == "something")
   }
  </code></pre>
  
  <p>But this will load ALL the records and that match the query and THEN apply the where clause. I want to add the where clause to the original query so that only the records matching both are returned.</p>