title: Typeorm .loadRelationCountAndMap returns zeros
body: <p>please help.
  I am trying to execute the following typeorm query:</p>
  <pre><code>  return await getRepository(Company)
      .createQueryBuilder(&quot;Company&quot;)
      .leftJoinAndSelect(&quot;Company.plants&quot;, &quot;Plant&quot;)
      .leftJoinAndSelect(&quot;Plant.documents&quot;, &quot;Document&quot;)
      .leftJoinAndSelect(&quot;Plant.notes&quot;, &quot;Note&quot;)
      .loadRelationCountAndMap(&quot;Plant.documentsCount&quot;, &quot;Plant.documents&quot;)
      .loadRelationCountAndMap(&quot;Plant.notesCount&quot;, &quot;Plant.notes&quot;)
      .getMany();
  </code></pre>
  <p>The idea was to select counts of documents and notes per each plant along with all plants for all companies.
  (Actually selecting notes and documents themselves was not needed, but i did it to prove that relations do work).</p>
  <p>Also I have specified the placeholder variables to keep counts in Plant entity:</p>
  <pre><code>  @OneToMany(() =&gt; Document, (document) =&gt; document.plant)
    documents: Document[];
    documentsCount: number;
  
    @OneToMany(() =&gt; Note, (note) =&gt; note.plant)
    notes: Note[];
    notesCount: number;
  </code></pre>
  <p>Strangely the returned Plant.documentsCount and Plant.notesCount are 0 (while the collections of documents and notes are not empty and are being selected).</p>
  <p>Another strange thing is that i don't see in SQL querires any attempts to select these counts, thus i hope typeorm itself would do counting (since it has collections selected correctly).</p>
  <p>Could anybody please give some advise on how to select these counts?</p>