title: ASP Net Core Web API: Client side GroupBy is not supported
body: <p>I am new here, and a newbie in asp.net core.</p>
  
  <p>I am writing a web api using asp.net core 3.0. I wrote the following API endpoint code to retrieve a list of <code>Databases</code> entities and group them by a field named <code>Value</code> from another object <code>Type</code>. </p>
  
  <pre class="lang-cs prettyprint-override"><code>//GET:api/Databases/graph
  [HttpGet("graph")]
  public async Task&lt;ActionResult&lt;IEnumerable&lt;IGrouping&lt;string, Database&gt;&gt;&gt;&gt; GetGraphDatabases()
  {
      return await _context.Databases
          .Include(t =&gt; t.Type)
          .Where(d =&gt; d.Type.Code == "DATABASE_TYPE")
          .GroupBy(d =&gt; d.Type.Value)
          .ToListAsync();
  }
  </code></pre>
  
  <p>But when I try to reach the endpoint, I get the following error message: <strong>InvalidOperationException: Client side GroupBy is not supported.</strong></p>
  
  <p>I checked this <a href="https://stackoverflow.com/questions/58138556/client-side-groupby-is-not-supported">answer</a> but it didn't help much.</p>
  
  <p>Can you please support.</p>