CODEWITHSUNDEEP
javascriptfirebasegoogle-cloud-firestore
Ivàn Gonzalez
Ivàn Gonzalez

Reputation: 109

"querySnapshot.forEach is not a function" in firestore

I'm trying to do a query to the database, to get all documents of sub-collection "roles" to redirect to different routes.

let userRef1 = db.collection('users').doc(currentUser.uid).collection('roles')
let cont = 0
let rol = ''
let rolStatus = ''

userRef1.get().then(function(querySnapshot) {                                                                                                                               
  querySnapshot.forEach(function(doc) {                                                                                                                            

    cont++ 
    rol = doc.data().rol
    rolStatus = doc.data().status                                         
  });

error on the console

Upvotes: 10

Views: 14708

Answers (5)

Ashwani Kumar Kushwaha
Ashwani Kumar Kushwaha

Reputation: 171

// Firebase App (the core Firebase SDK) is always required and must be listed first
import * as firebase from "firebase/app";
// Add the Firebase products that you want to use
import "firebase/auth";
import "firebase/firestore";
const firebaseConfig = {
  apiKey: "AIzaSyDNdWutrJ3Axpm-8ngNhzkzcw1g3QvkeFM",
  authDomain: "books-7bd8b.firebaseapp.com",
  databaseURL: "https://books-7bd8b.firebaseio.com",
  projectId: "books-7bd8b",
  storageBucket: "books-7bd8b.appspot.com",
  messagingSenderId: "385706228283",
  appId: "1:385706228283:web:a3c2c9585dd74d54693a1e",
};
firebase.initializeApp(firebaseConfig);
export const firebaseAuth = firebase.auth();
export const firestore = firebase.firestore();
export default firebase;

Upvotes: 1

Ashwani Kumar Kushwaha
Ashwani Kumar Kushwaha

Reputation: 171

import { firestore } from "../../firebase";
export const loadCategories = () => {
  return (dispatch, getState) => {
    firestore
      .collection("CATEGORIES")
      .get()
      .then((querySnapshot) => {
        if (!querySnapshot.empty) {
          querySnapshot.forEach((doc) => {
            console.log(doc.id, "=>", doc.data());
          });
        }
      })
      .catch((error) => {
        console.log(error);
      });
  };
};

Upvotes: 2

Soufiane Odf
Soufiane Odf

Reputation: 1112

You should check if it always exists before doing your logic:

userRef1.get().then(function(querySnapshot) { 

         if(querySnapshot)
         {
           querySnapshot.forEach(function(doc) { 
           
           ...you thing

         }                                                                                                                         
})

Upvotes: 0

Jason Berryman
Jason Berryman

Reputation: 4898

It is not clear what you are doing with the rol and status variables. You have declared them as though you are storing a single value, yet you are returning an array of roles and iterating through them.

With regards to getting the results, if your browser supports ES6, then you could do the following:

let userRef1 = db.collection(`users/${currentUser.uid}/roles`)
let cont = 0
let rol;
let rolStatus;

return userRef1.get()
  .then(querySnapshot => {
    // Check if there is data
    if(!querySnapshot.empty) {
      // Create an array containing only the document data
      querySnapshot = querySnapshot.map(documentSnapshot => documentSnapshot.data());
      querySnapshot.forEach(doc => {
        let {rol, status} = doc;
        console.log(`rol: ${rol} - status: ${status}`);
      });
    } else {
      console.log('No data to show');
    }
  })
  .catch(err => {
    console.error(err);
  });

Please note: I've only tested this with the Node SDK

Upvotes: 1

JeffMinsungKim
JeffMinsungKim

Reputation: 2140

I have a collection of users including uid just like yours. And for each user, it contains a sub-collection called friends.

Currently, I'm using the following code for my project without having any issues.

module.exports = ({ functions, firestore }) => {
  return functions.firestore.document('/users/{uid}').onDelete((event) => {

    const userFriendsRef = getFriendsRef(firestore, uid);

     userFriendsRef.get().then(snapshot => {
       if (snapshot.docs.length === 0) {
         console.log(`User has no friend list.`);
         return;
      } else {
        snapshot.forEach(doc => {
          // call some func using doc.id
        });
      }
     }
  }
};

function getFriendsRef(firestore, uid) {
  return firestore.doc(`users/${uid}`).collection('friends');
}

Give it a try to fix your code from

db.collection('users').doc(currentUser.uid).collection('roles')

to

db.doc(`users/${currentUser.uid}`).collection('roles')

Upvotes: 1

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