title: Is there a way to exclude NULL values from Azure Cognitive Search Indexes
body: <p>So for example we have field 1 up to 10. I want to index all the field in Azure Search, so you can filter, search on those filters.</p>
  <p>My Question is, is there a way to just exclude the fields that are NULL from a specific ID, so not store them in Azure search? See example underneath.</p>
  <p>The data itself is initially stored in Azure Cosmos Database.
  In Azure Cosmos DB it would like this:</p>
  <ul>
  <li>Id 1</li>
  <li>field 1: a</li>
  <li>field 2: b</li>
  <li>field 5: c</li>
  <li>field 6: d</li>
  <li>field 8: e</li>
  </ul>
  <hr />
  <hr />
  <ul>
  <li>Id 2</li>
  <li>field 3: a</li>
  <li>field 2: b</li>
  <li>field 5: c</li>
  <li>field 9: d</li>
  <li>field 10: e</li>
  </ul>
  <p>However in Azure Search Index, it looks like this:</p>
  <ul>
  <li>Id 1</li>
  <li>field 1:a</li>
  <li>field 2:b</li>
  <li>field 3:NULL</li>
  <li>field 4:NULL</li>
  <li>field 5:c</li>
  <li>field 6:d</li>
  <li>field 7:NULL</li>
  <li>field 8:e</li>
  <li>field 9:NULL</li>
  <li>field 10:NULL</li>
  </ul>
  <hr />
  <hr />
  <ul>
  <li>Id 2</li>
  <li>field 1:NULL</li>
  <li>field 2:b</li>
  <li>field 3:a</li>
  <li>field 4:NULL</li>
  <li>field 5:c</li>
  <li>field 6:NULL</li>
  <li>field 7:NULL</li>
  <li>field 8:NULL</li>
  <li>field 9:d</li>
  <li>field 10:e</li>
  </ul>