How can I get child value in Firebase database with android?

Question

Previously, I asked to get the data in firebase. But I can't get the value... My database like this.

{Singer :
    {Eminem :
        {01 :
            songName : "Rap god",
            songType : "type01"
        },
        {02 :
            songName : "Till I collapse",
            songType : "type02"
        }
    },
    {Lauv :
        {01 :
            songName : "I Like Me Better",
            songType : "type01"
        },
        {02 :
            songName : "lonely",
            songType : "type03"
        }
    },
    {Alan Walker :
        {01 : 
            songName : "All Falls Down",
            songType : "type02"
        },
        {02 :
            songName : "On My Way",
            songType : "type01"
        }
    }  
}

I want to get all type01 in Singer all of them. I tried code like this

@Override
public void onBindViewHolder(@NonNull MyHolder holder, int i) {
    ...
    Query myQuery = FirebaseDatabase.getInstance().getReference().child("Singer").orderByChlid("songType").equalsTo("type01");
    FirebaseRecyclerOption.Builder<ItemModel>.setQuery(myQuery, new SanpshotParser<ItemModel>() {
        @NonNull
        @Override
        public ItemModel parseSnapshot(@NonNull DataSnapshot snapshot) {
            String songStr = snapshot.child("songName").getValue().toString();
            String typeStr = snapshot.child("songType").getValue().toString();

            return new ItemModel(songStr, typeStr);
        }
    }).build();
    ...
}

But I can't get what I want. FirebaseDatabase.getInstance().getReference().child("Singer").orderByChild("songType").equalsTo("type01") can't read the data in function parseSnapshot. How can I get all the singer's songs that type is type01?

your trying to retrieve the child of child from above query. So it won't work as you expected. Even frank van puff explained in his [answer](https://stackoverflow.com/a/43295289/10182897) — Ashish, Sep 25 '19 at 03:55
In my previous answer I gave you the two options: 1) build your own adapter, 2) change your data structure to a flat list of songs, so FirebaseUI can work with it. You seem to be doing neither here, which is the reason it won't work. — Frank van Puffelen, Sep 25 '19 at 05:05

score 2 · Answer 1 · answered Sep 25 '19 at 03:57

2

You need to go one step deeper so the query can access songType:

FirebaseDatabase.getInstance().getReference().child("Singer").child("Eminem").orderByChild("songType").equalsTo("type01")

answered Sep 25 '19 at 03:57

Peter Haddad

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I suggest to put recyclerview to retrieve the list of singer. Then get onClick of each singer name retrieve the type01 song – Ashish Sep 25 '19 at 04:00
Me too good idea – Peter Haddad Sep 25 '19 at 04:02
There is only/at most one song with `type01` per singer it seems. So it could make sense to show *that* for each singer. It's just that the data structure OP uses isn't suitable for doing that FirebaseUI to do that, which is why I recommended a flat data structure in answer to their previous question. – Frank van Puffelen Sep 25 '19 at 05:07

How can I get child value in Firebase database with android?

1 Answers1