How to avoid creating multiple docs in firebase everytime user update his profile info in flutter-CodePudding

So I just created a form for the user to key in his/her personal info in flutter. This is the code as a begining:


import 'package:cloud_firestore/cloud_firestore.dart';

class InsertProfInfoToDB {
  String? name;
  int? height;
  int? weight;
  String? gender;
  String? birthDateInString;
  InsertProfInfoToDB();

  Map <String, dynamic> toJson() => {'name': name, 'height': height,
    'weight' : weight, 'gender' : gender,
    'birthDateInString' : birthDateInString};

  InsertProfInfoToDB.fromSnapshot(snapshot)
      : name = snapshot.data()['name'],
        height = snapshot.data()['height'],
        weight = snapshot.data()['weight'],
        gender = snapshot.data()['gender'],
        birthDateInString = snapshot.data()['birthDateInString'];




}


 Future<void> submitForm () async {

 String userID = FirebaseAuth.instance.currentUser!.uid;

   int height =int.parse(heightController.text);
   int weight =int.parse(weightController.text);

   _insertProfInfoToDBToDB.name = nameController.text;
   _insertProfInfoToDBToDB.birthDateInString = birthDateInString;
   _insertProfInfoToDBToDB.height = height;
   _insertProfInfoToDBToDB.weight = weight;
   _insertProfInfoToDBToDB.gender = select;

   await FirebaseFirestore.instance
         .collection('users')
         .doc(userID)
         .collection('personalInfo')
         .add(_insertProfInfoToDBToDB.toJson());
 }

With this code, everytime I submit the form, a new doc will be created with the user info. How can I make it so that if the user info is exicted on the DB then update the new values to the same doc.

I tried to specify the name of the doc where the info is saved but I got an error saying

The method 'add' isn't defined for the type 'DocumentReference'.

CodePudding user response：

you can use update method

await FirebaseFirestore.instance
         .collection('users')
         .doc(userID).update();

CodePudding user response：

Since I had a collection that contains docs which contains collections, It was a bit tricky to get it done but here is how I did it. First I created this function to get the doc ID and added it to initState with help from this answer https://stackoverflow.com/a/67857128/18205996.

Future <void> getID () async {
  var collection = FirebaseFirestore.instance.
  collection('users').doc(userID).collection('personalInfo');
  var querySnapshots = await collection.get();
  for (var snapshot in querySnapshots.docs) {
    documentID = snapshot.id;
    print(documentID);
  }
}

Then the the Update function:

 Future<void> submitForm () async {
    int height =int.parse(heightController.text);
    int weight =int.parse(weightController.text);

    _insertProfInfoToDBToDB.name = nameController.text;
    _insertProfInfoToDBToDB.birthDateInString = birthDateInString;
    _insertProfInfoToDBToDB.height = height;
    _insertProfInfoToDBToDB.weight = weight;
    _insertProfInfoToDBToDB.gender = select;

    await FirebaseFirestore.instance
          .collection('users')
          .doc(userID).collection('personalInfo').doc(documentID)
        .update(_insertProfInfoToDBToDB.toJson());

  }