title: How to filter email using firebase android?
body: <p>I am new to firebase. I want to search for some email ids using <code>orderbychild()</code> query. Please help me, I have posted my code below. This code returns value empty.</p>
  
  <pre><code>private void getFilterDataByEmail(String s) {
          mSearchProgress.setVisibility(View.VISIBLE);
          userLists.clear();
          final DatabaseReference usersReference = FirebaseDatabase.getInstance().getReference();
          Query query;// = usersReference.child(ARG_USERS).orderByChild("username").startAt(s.toString());
  
          query = usersReference.child(ARG_USERS).orderByChild("email")
                  .startAt(s.toString()).endAt(s + "\uf8ff");
          query.addListenerForSingleValueEvent(new ValueEventListener() {
              @Override
              public void onDataChange(DataSnapshot dataSnapshot) {
  
                  doTask(dataSnapshot, true);
              }
  
              @Override
              public void onCancelled(DatabaseError databaseError) {
                  mSearchProgress.setVisibility(View.INVISIBLE);
                  suggestionListLayout.setVisibility(View.GONE);
              }
          });
      }
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/GnhH4.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/GnhH4.png" alt="This is my firebase database"></a></p>
  
  <p><a href="https://i.stack.imgur.com/kptHC.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/kptHC.png" alt="This is my search box in the app"></a></p>
  
  <p><a href="https://i.stack.imgur.com/whZkE.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/whZkE.png" alt="enter image description here"></a></p>
  
  <p>The response I have got  is:
  DataSnapshot { key = users, value = null }</p>