How to get, set, update and delete data from the cloud firestore in Flutter?

Question

I tried some code but getting an exception.

The Exception that I'm getting: java.lang.IllegalArgumentException: Invalid document reference. Document references must have an even number of segments, but Users has 1

I searched for it, according to this, Document references must have an even number of segments like: Collection - document - Collection - document - Collection - document

Query for getting data from firestore:

String getIsNewUSer;
Firestore.instance.collection('Users').document(uid).get().then((DocumentSnapshot document){
       print("document_build:$document");
        setState(() {
         getIsNewUSer=document['IsNewUser'];
         print("getIsNewUSe:$getIsNewUSer");
        });

    });

Query for Updating data to the firestore:

Firestore.instance
            .collection('Users')
            .document(uid)
            .updateData({
              "IsNewUser":"1"
            }).then((result){
              print("new USer true");
            }).catchError((onError){
             print("onError");
            });

These code line at I'm getting above Exception.

initState:

 void initState()  {
    super.initState();
    this.uid = '';

FirebaseAuth.instance.currentUser().then((val){
      setState(() {
      this.uid= val.uid; 
       print("uid_init: $uid");
      });
   });

}

Am I doing wrong?????..

Answer 1

Null safe code:

• Get data:

  var collection = FirebaseFirestore.instance.collection('collection');
  var docSnapshot = await collection.doc('doc_id').get();
  Map<String, dynamic>? data = docSnapshot.data();
  

• Set data:

  var collection = FirebaseFirestore.instance.collection('collection');
  collection.add(someData);
  

• Update data:

  var collection = FirebaseFirestore.instance.collection('collection');
  collection 
      .doc('foo_id') // <-- Doc ID where data should be updated.
      .update(newData);
  

• Delete data:

  var collection = FirebaseFirestore.instance.collection('collection');
  collection 
      .doc('some_id') // <-- Doc ID to be deleted. 
      .delete();