firebase get database data code example

Example 1: recieve data from firebase database

const [rooms, setRooms] = useState([]);

useEffect(() => {
	const getRooms = db.collection('rooms').onSnapshot((snapshot) => {
		setRooms(
			snapshot.docs.map((doc) => {
				return { id: doc.id, data: doc.data() };
			})
		);
	});
		return () => {
		getRooms();
	};
}, []);

Example 2: firebase realtime database read data

If you want to get a specific data using a phone number then you can use a Query like this

DatabaseReference database = FirebaseDatabase.getInstance().getReference();
DatabaseReference ref = database.child("profiles");

Query phoneQuery = ref.orderByChild(phoneNo).equalTo("+923336091371");
phoneQuery.addListenerForSingleValueEvent(new ValueEventListener() {
    @Override
    public void onDataChange(DataSnapshot dataSnapshot) {
        for(DataSnapshot singleSnapshot : dataSnapshot.getChildren()){
           user = singleSnapshot.getValue(User.class); 
        }
    }
    @Override
    public void onCancelled(DatabaseError databaseError) {
        Log.e(TAG, "onCancelled", databaseError.toException());
    }
});
I think this is the best method.