CODEWITHSUNDEEP
flutterdartgoogle-cloud-firestore
Milie
Milie

Reputation: 435

How to get Firestore document ID?

In Dart, how do you retrieve the auto-generated ID within a collection's document?

I have a collection called "users" that has auto ID documents with the users details. How do you retrieve that ID?

ID eg: yyHYmbDelykMPDWXHJaV

enter image description here

I'm trying to get this id. When the document is first created, when user is first created, the user.uid is stored in it's collection.

I can retrieve all the data from the users database, which I don't want: 

  void getData() {
    databaseReference
     .collection('users')
     .getDocuments()
     .then((QuerySnapshot snapshot) {
    snapshot.documents.forEach((f) => print('${f.data}'));
   });
  }

I can get a future reference for the current user's user.uid but that still doesn't give me the unique document ID.

  Future<DocumentReference> getUserDoc() async {
    final FirebaseAuth _auth = FirebaseAuth.instance;
    final Firestore _firestore = Firestore.instance;
    FirebaseUser user = await _auth.currentUser();
    DocumentReference ref = 
      _firestore.collection('users').document(user.uid);
    print(ref);
    return ref;
  }

Is it possible to search the user.uid against the database users and retrieve the ID that way?

Upvotes: 7

Views: 13983

Answers (1)

Nolence
Nolence

Reputation: 2264

To get the auto generated id, you can just call the document method on whatever collection you're trying to get a document from and the returned value will have a getter for documentID

final userDocument = usersCollection.document();
final documentID = userDocument.documentID;

You usually do this when you first want to create a document. To retrieve the documentID after you've created it, I'd add it to the user document itself:

userDocument.setData({
  documentID: documentID,
  /* ... */
});

Instead of using the auto generated documentID though, I personally use the firebase user's uid property just because it ties it back to Firebase auth

// user is a FirebaseUser
final userDocument = usersCollection.document(user.uid);
userDocument.setData({
  uid: user.uid,
  // ...displayName, email, etc.
});

Upvotes: 6

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