title: linq distinct field
body: <p>how set distinct to this query</p>
  
  <pre><code>return _dataContext.ProjectPictures.Include("Projects").Include("ProjectPictureTypes").Where(p =&gt; p.ProjectPictureTypes.Id == 1).ToList();
  </code></pre>
  
  <p>i need something like </p>
  
  <pre><code>return _dataContext.ProjectPictures.Include("Projects").Include("ProjectPictureTypes").Where(p =&gt; p.ProjectPictureTypes.Id == 1).Distinct(p=&gt;p.Projects.Id).ToList();
  </code></pre>