Android: Retrieve data of a specific user from a Firebase database

Question

I am trying to read \"specific\" data from my firebase realtime database. I have seen examples of getting all data from a table and going through it to find the

Answer 1

You need to do the query:

orderByChild("FirstName").equalTo(name);

DatabaseReference reference = FirebaseDatabase.getInstance().getReference("user");

reference.orderByChild("firstName").equalTo(name).addListenerForSingleValueEvent(new ValueEventListener() {
 @Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot datas: dataSnapshot.getChildren()){
   String familyname=datas.child("familyName").getValue().toString();
    }
 }
   @Override
public void onCancelled(DatabaseError databaseError) {
  }
 });

Assuming you have this database:

user
  randomid
     firstName: John
     familyName: familyName_here

---

Another way is to use the userid to be able to retrieve the data, but as I see in the question you are saving a random id using push().

You need to retrieve the userid:

FirebaseUser user=FirebaseAuth.getInstance().getCurrentUser();
String userid=user.getUid();

then add it to the database:

 myRef.child(userid).setValue(user);

then to retrieve data only for John:

FirebaseUser user=FirebaseAuth.getInstance().getCurrentUser();
String userid=user.getUid();
DatabaseReference reference = FirebaseDatabase.getInstance().getReference("user");
reference.child(userid).addListenerForSingleValueEvent(new ValueEventListener() {..}

Answer 2

Query specific_user = myRef.child(FirebaseAuth.getInstance().getCurrentUser().getUid());
      specific_user.addListenerForSingleValueEvent(
              new ValueEventListener() {
              @Override
              public void onDataChange(DataSnapshot dataSnapshot) {
                     //here you will get the data
                  }

              @Override
              public void onCancelled(DatabaseError databaseError) {    
                                           }
                           });

Answer 3

You have to collect the response from firebase to somePOJO Class

follow link : https://firebase.google.com/docs/database/admin/retrieve-data

As you can see in onDataChange() the response is collected in Post.class which is POJO class.