firebase / firestore docs queries Not working - javascript

Question

As firestore is new, i am having problems using it.

I have to get Collection of all users and traverse it. But it is not working.

db.collection("users").get().then(function(querySnapshot){
      console.log(querySnapshot.data());
});

It says:

querySnapshot.data is not a function

And following code:

callFireBase(mobileToCheck){
        db.collection("users").where("mobile_no", '==', mobileToCheck).get().then(function(querySnapshot){
            if (querySnapshot.exists) {
                var userData = querySnapshot.data();
                var userId = querySnapshot.id;
                console.log(mobileToCheck + "Exist In DB");
            }else{
                console.log(mobileToCheck + "Do Not Exist In DB");
            }
        });
}

Is always printing

923052273575 Do Not Exist In DB

Even if it exists, See following image for reference. In docs they have told this (i have used) way.

Answer 1

It looks that tou want to call.data() on collection of documents, not one document. Please see if this code works:

db.collection("users").get().then(function(querySnapshot){
  querySnapshot.forEach(doc => {
     console.log(doc.data());
  });
}).catch(err => {
   console.log('Error getting documents', err);
});

Answer 2

You should use docs.map then doc.data(). Here is how to do it with Firestore using async await syntax

import firebase from 'react-native-firebase'

async fetchTop() {
  const ref = firebase.firestore().collection('people')
  const snapshot = await ref.orderBy('point').limit(30).get()
  return snapshot.docs.map((doc) => {
    return doc.data()
  })
}