title: Is there an Azure database equivalent to Firebase clients being able to listen for database changes?
body: <p>Firebase's realtime database SDK has callback methods built in which allow the client to listen for database changes. (e.g. as per <a href="https://firebase.google.com/docs/database/android/start/" rel="noreferrer">https://firebase.google.com/docs/database/android/start/</a>)</p>
  
  <p>Does Azure have any functionality like that in either the SQL Database or DocumentDB products? If not, why not? And what is the best way to achieve this functionality using Azure?</p>
  
  <p>Thanks.</p>
  
  <p><strong>Edit</strong> context: I'm building a cross-platform mobile app using Xamarin.</p>