title: Firebase listener is not called while trying to read data
body: <p>I am new to using Firebase database and also slowly learning Android. Anyway I tried to store data in Firebase database and it was successful.
  Now I am trying to read data from Firebase database, but unfortunately I cannot do it.</p>
  
  <p>I read a lot to query data from the Firebase database but still not able to get it working.</p>
  
  <p>Below is the data stored in Firebase Realtime Database.</p>
  
  <p><a href="https://i.stack.imgur.com/WmmRu.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/WmmRu.jpg" alt="This is the stored data in firebase realtime database"></a></p>
  
  <p>And below is my reference code which I am trying to get data.
  I have connected the mobile for using adb to debug the android application.
  While trying to debug, I kept breakpoint at <code>onDataChange</code> but it was never hit.
  I could see some information in the query value but I could not get full information of the query. The value does not contain my query result.</p>
  
  <pre><code>@Override
  protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_view_request);
  
      databaseRequests = FirebaseDatabase.getInstance().getReference("Requests");
      Query query = databaseRequests.orderByChild("requestNo").equalTo(11);
      query.addListenerForSingleValueEvent(new ValueEventListener() {
          @Override
          public void onDataChange(DataSnapshot dataSnapshot) {
              Request request = dataSnapshot.getValue(Request.class);
              Log.d("CREATION"," Request.no:" + request.requestNo +" Request Purpose:" + request.requestPurpose);
          }
  
          @Override
          public void onCancelled(DatabaseError databaseError) {
  
          }
      });
  </code></pre>
  
  <p>Let me know what is going wrong? I tried to debug a lot, but I am sure something I am missing.</p>