将文档添加到云 Firestore 中的指定集合时如何更新文档？

Question

I have 2 collections in my firestore (global and local) and when I add a doc to local I need to update a field in the global doc by 1

Below is the code I have for the same. I am very new to this so I might have some syntactical error as well, please do highlight if you find any.

const functions = require("firebase-functions");
const admin = require("firebase-admin");

exports.helloWorld = functions.https.onRequest((request, response) => {
  response.send("Hello world");
}); // For testing, even this is not being deployed

exports.updateGlobal = functions.firestore
  .document("/local/{id}")
  .onCreate((snapshot, context) => {
    console.log(snapshot.data());
    return admin
      .firebase()
      .doc("global/{id}")
      .update({
        total: admin.firestore.FieldValue.increment(1),
     });
  });

The Terminal says "function failed on loading user code" Before this, it showed something along the lines of "admin is undefined" or "cannot access firestore of undefined" which I'm unable to replicate now.

This is a part of a react app which has normal firestore working through firebase npm module Any other info needed regarding the issue I'll edit the question accordingly, thank you so much for the help.

Answer 1

In addition to loading the firebase-functions and firebase-admin modules, you need to initialize an admin app instance from which Cloud Firestore changes can be made, as follows:

const functions = require('firebase-functions');
const admin = require('firebase-admin');

admin.initializeApp();

//...

---

I see another problem in your CF. You need to use the context object to get the value of id .

exports.updateGlobal = functions.firestore
  .document("/local/{id}")
  .onCreate((snapshot, context) => {
    
   const docId = context.params.id;

    return admin
      .firebase()
      .doc("global/" + docId)
      .update({
        total: admin.firestore.FieldValue.increment(1),
     });
  });

You can also use template literals as follows:

    return admin
      .firebase()
      .doc(`global/${docId}`)
      //...