Firebase Snapshot.Key Not Returning Actual Key

Firebase snapshot.key not returning actual key?

When you run a query at a location, the result will be a list of the matching children. Even if there is only a single matching item, the result will be a list of one child.

You're printing the key of all resulting children. Since there is no single result, the SDK prints the key of the location/collection that you queried: users.

What you're likely looking for is to loop over the matching children and print their keys:

let query = usersRef.queryOrderedByChild("email").queryEqualToValue(email)
query.observeEventType(.Value, withBlock: { snapshot in
    for child in snapshot.children {
        print(child.key)
    }
})

can't get the key of a datasnapshot

As @FrankVanPuffelen suggested, it seems 'key' is no longer a function, but rather a variable. So

var key = dataSnapshot.key;

does work, but

var key = dataSnapshot.key();

doesn't.

Unable to retrieve keys of firebase data

I got it. Apparently you do not need to put the (). So I changed

var key = childSnapshot.key();

to

var key = childSnapshot.key;

and it worked.

How to pull snapshot key & values into list through Map ?

In this code you only use the element.value of each node in your results:

return Items.fromRTDB(Map<String, dynamic>.from(element.value));

If you also want to get the key of each item, you will have to also use element.key in there and pass that to your Items object.

---

Something like this:

Items.fromRTDB(element.key, Map<String, dynamic>.from(element.value));

...

class Items{
  final String key;
  final String item;
  final String expiryDate;
  final String quantity;
  final String user;

  Items({required this.key, required this.item, required this.expiryDate, required this.quantity, required this.user});

  //Mapping from real-time database
  factory Items.fromRTDB(String key, Map<String, dynamic> data) {
    return Items(
      key: key,
      item: data['item'],
      expiryDate: data['exp'],
      quantity: data['qty'],
      user: data['user'],
    );
  }
}

Firebase data snapshot returns key but no .val()

The issue was that I didn't wait for Firebase to return the userID before running my query:

// this.props.userID is undefined    
let userPath = `user/${this.props.userID}/${this.state.topic}`

The solution was to call this.databaseListenerOn() within onAuthStateChanged to ensure that it's called once I have the userID.

How to get the key from a Firebase data snapshot?

You could do something like this:

var key = Object.keys(snapshot.val())[0];

Ref: https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Object/keys

The Object.keys() method returns an array of a given object's own
enumerable properties, in the same order as that provided by a
for...in loop (the difference being that a for-in loop enumerates
properties in the prototype chain as well).

dataSnapShot.getKey() not returning the actual push key

When you execute a query against the Firebase Database, there will potentially be multiple results. So the snapshot contains a list of those results. Even if there is only a single result, the snapshot will contain a list of one result.

So to get the snapshot of the individual child node, you need to loop over the result:

Query reference=FirebaseDatabase.getInstance().getReference().child("products").orderByChild("name").equalTo("iphon");
reference.addListenerForSingleValueEvent(new ValueEventListener() {
    @Override
    public void onDataChange(DataSnapshot dataSnapshot) {
        for (DataSnapshot childSnapshot: dataSnapshot.getChildren()) {
            String key=childSnapshot.getKey();
            Log.i(TAG,key);
        }
    }

How to get value from firebase without the snapshot key [JS]

Firebase Realtime Database queries work on single path, and then order/filter on a value at a fixed path under each direct child node. In your case, if you know whether the user is active or pending, you can find a specific value with:

const ref = firebase.database().ref("friends");
const query = ref.child("active").orderByValue().equalTo("JrvFaTDGV6TnkZq6uGMNICxwGwo2")
const results = query.get();
results.forEach((snapshot) => {
  console.log(`Found value ${snapshot.val()} under key ${snapshot.key}`)
})

---

There is no way to perform the same query across both active and pending nodes at the same time, so you will either have to perform a separate query for each of those, or change your data model to have a single flat list of users. In that case you'll likely store the status and UID for each user as a child property, and use orderByChild("uid").

---

Also note that using push IDs as keys seems an antipattern here, as my guess is that each UID should only have one status. A better data model for this is:

friends: {
  "JrvFaTDGV6TnkZq6uGMNICxwGwo2": {
    status: "active"
  }
}

---

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