Firebase Firestore Increment FieldValue does not increment

Question

so i've read all the documentation everything about increment a counter in a Firestore database. I have this code

const admin = require("firebase-admin");
const db = admin.firestore();
...
db
.collection("settings")
.doc("totalUsers")
.set({
count: firebase.firestore.FieldValue.increment(1),
});

And i just doesn't increment the counter at all. No errors no logs no nothing. In my Firestore i have a collection of settings and a document totalUsers with a property count that is a number type and it equals to 1.

Am I doing something wrong? Am I missing anything? Any help appreciated!

Can you show the code? Hope you didn't forget to `await` the async call when adding the try-catch. — Hiranya Jayathilaka, Apr 13 '20 at 20:04
I found out, it was the i was setting instead of updating. Supposed to be `.update` instead of `.set`... silly me. Thank you for your help! Your comment actually sparked something in my mind :) — Constantin Chirila, Apr 14 '20 at 15:36

Louis Coulet · Answer 1 · 2021-02-08T21:09:20.297

13

increment works with both update and set.
For it to actually increment the field you can:

use update, but the documents must exist already
use set with option merge: true or mergeFields: "something", with something the name of the field being incremented

edited Feb 08 '21 at 21:09

answered Feb 08 '21 at 21:02

Louis Coulet

3,663
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This is the most complete answer. – John T Jul 15 '21 at 05:24
1

Yes, if you don't use the `{ merge: true }` option with `set`, `firebase.firestore.FieldValue.increment(0)` will set your field to zero instead of performing **NO INCREMENT**. This is particularly useful when your incremental value can be a variable with situation that it can be sometimes ZERO. – Antonio Ooi Jun 21 '22 at 08:43
for nested fields it's now a requirement to use set with merge true. Update does not work and this is not reflected in the firebase docs – van Jan 26 '23 at 15:25
I just checked and it still works with ```update```, you need to use the dot notation to update nested fields: https://firebase.google.com/docs/firestore/manage-data/add-data#update_fields_in_nested_objects – Louis Coulet Jan 26 '23 at 20:56

score 5 · Accepted Answer · answered Apr 14 '20 at 15:38

5

For anyone having issues with this, be careful to use the .update() method instead .set(). Also you need to have a value existing in the firestore that so it has something to increment.

answered Apr 14 '20 at 15:38

Constantin Chirila

1,979
2
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2

I have a similar issue and the funny thing is I am using FieldValue increment as a set() operation on an oncreate trigger. But for another function, i am using onwrite trigger and Fieldvalue increment does not work. But in the documentation it says works with set and update – Archid Aug 14 '20 at 21:45
I had a missing value, so update was trying to increment **nothing**. Thanks for help! – drpawelo Jun 29 '22 at 20:37

score 3 · Answer 3 · answered Apr 13 '20 at 14:38

3

Since you are using the Admin SDK, you should do as follows:

count: admin.firestore.FieldValue.increment(1)

answered Apr 13 '20 at 14:38

Renaud Tarnec

79,263
10
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1

Unfortunately that didnt work. I have updated my question as what you have said made sense. – Constantin Chirila Apr 13 '20 at 16:56
Where exactly is your code executed? In a Node.js server? In a Cloud Function? How do you initialize the Admin SDK? – Renaud Tarnec Apr 14 '20 at 07:24
I found out, it was the i was setting instead of updating. Supposed to be `.update` instead of `.set`... silly me. Thank you for your help! – Constantin Chirila Apr 14 '20 at 15:36

score 0 · Answer 4 · edited Oct 09 '21 at 13:01

Try with this: (this is my code and works for me)

var firebaseUser = await FirebaseAuth
                        .instance
                        .currentUser();
DocumentReference query = Firestore.instance
                              .collection("users")
                              .document(firebaseUser.uid);
                                                    Navigator.pushReplacement(context, MaterialPageRoute(builder: (context) => LoginView()));
 var loginSuccess = wait model.getdata(_inputCuit.text);

 if (loginSuccess) {
     query.updateData({ "queries": FieldValue.increment(1)});
 }

The key area is the .increment() method

Firebase Firestore Increment FieldValue does not increment

4 Answers4

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