CODEWITHSUNDEEP
javaandroidfirebasegoogle-cloud-firestore
Martynas
Martynas

Reputation: 319

How to check if the field exists in firestore?

I am checking whether the Boolean field called attending exists, however I am not sure how to do that.

Is there a function such as .child().exists() or something similar that I could use?

firebaseFirestore.collection("Events")
    .document(ID)
    .collection("Users")
    .get()
    .addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {
        @Override
        public void onComplete(@NonNull Task<QuerySnapshot> task) {
            if(task.isSuccessful()) {
                for(QueryDocumentSnapshot document: task.getResult()){
                    attending = document.getBoolean("attending");
                }
            }
        }
    });

Upvotes: 11

Views: 25590

Answers (9)

awariat
awariat

Reputation: 382

You can use hasOwnProperty

if (docSnap.exists()) {
            ...
            if (docSnap.data().hasOwnProperty('myField')) {
                ...
            } else {
                console.log("No such field!");
            }
        } else {
            console.log("No such document!");
           
        }

Upvotes: 0

Sergio Samaan
Sergio Samaan

Reputation: 95

How about using:

QueryDocumentSnapshot<Map<String, dynamic>> data = 'some data';

if (data.data().containsKey(fieldName)) {
// do something.
}

Upvotes: 0

Vincy
Vincy

Reputation: 1078

instead of documentSnapshot.get("attending"); do this documentSnapshot.ContainsField("attending");

If the field exists it will return true else returns false.

Upvotes: 0

Nicolas
Nicolas

Reputation: 1

I didn't find any solution so what I do is a try - catch (sorry Flutter / Dart, not java):

  bool attendingFieldExists = true;
  DocumentSnapshot documentSnapshot = 
  // your Document Query here
  await FirebaseFirestore.instance 
      .collection('collection')
      .doc(FirebaseAuth.instance.currentUser?.uid)
      .get();
  // trying to get "attending" field will throw an exception
  // if not existing
  try {
    documentSnapshot.get("attending");
  } catch (e) {
    attendingFieldExists = false;
    print("oops.. exception $e");
  }

Then you can adapt the code you want to apply depending on attendingFieldExists. I'm new to Flutter / Dart so not sure this is the best way to handle this.. but it works for me.

Upvotes: 0

Noman Shaikh
Noman Shaikh

Reputation: 170

I use following boolean method may be someone else can

for(QueryDocumentSnapshot document: task.getResult()){
    if(document.contains("attending")){
           attending = document.getBoolean("attending");
    }
}

Upvotes: 0

Sumit yadu
Sumit yadu

Reputation: 53

Here is how you can achieve it or you may have resolved already, this for any one searches for solution.

As per the documentation:

CollectionReference citiesRef = db.collection("cities");

Query query = citiesRef.whereNotEqualTo("capital", false);

This query returns every city document where the capital field exists with a value other than false or null. This includes city documents where the capital field value equals true or any non-boolean value besides null.

For more information : https://cloud.google.com/firestore/docs/query-data/order-limit-data#java_5

Upvotes: 0

Bhoomika Chauhan
Bhoomika Chauhan

Reputation: 1026

You can check firestore document exists using this,

CollectionReference mobileRef = db.collection("mobiles");
 await mobileRef.doc(id))
              .get().then((mobileDoc) async {
            if(mobileDoc.exists){
            print("Exists");
            }
        });

Upvotes: -3

Peter Haddad
Peter Haddad

Reputation: 80914

You can do the following:

  if(task.isSuccessful()){
    for(QueryDocumentSnapshot document: task.getResult()){
       if (document.exists()) {
          if(document.getBoolean("attending") != null){
             Log.d(TAG, "attending field exists");
          }
        }
      }
  }

From the docs:

public boolean exists ()

Returns true if the document existed in this snapshot.

Upvotes: 5

Doug Stevenson
Doug Stevenson

Reputation: 317402

What you're doing now is correct - you have to read the document and examine the snapshot to see if the field exists. There is no shorter way to do this.

Upvotes: 4

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