How to create/update multiple documents at once in Firestore

Question

Is it possible to store multiple documents in Firestore with only one request? With this loop it's possible but this would cause one save operation per item in the list.

for (counter in counters) {     val counterDocRef = FirebaseFirestore.getInstance()             .document("users/${auth.currentUser!!.uid}/lists/${listId}/counters/${counter.id}")     val counterData = mapOf(             "name" to counter.name,             "score" to counter.score,     )     counterDocRef.set(counterData) } 

Answer 1

From Firebase documentation :

You can also execute multiple operations as a single batch, with any combination of the set(), update(), or delete() methods. You can batch writes across multiple documents, and all operations in the batch complete atomically.

// Get a new write batch WriteBatch batch = db.batch();  // Set the value of 'NYC' DocumentReference nycRef = db.collection("cities").document("NYC"); batch.set(nycRef, new City());  // Update the population of 'SF' DocumentReference sfRef = db.collection("cities").document("SF"); batch.update(sfRef, "population", 1000000L);  // Delete the city 'LA' DocumentReference laRef = db.collection("cities").document("LA"); batch.delete(laRef);  // Commit the batch batch.commit().addOnCompleteListener(new OnCompleteListener<Void>() {     @Override     public void onComplete(@NonNull Task<Void> task) {         // ...     } }); 

Firestore multiple write operations

Hope it helps..

Answer 2

Update some properties on all documents in a collection:

resetScore(): Promise<void> {   return this.usersCollectionRef.ref.get().then(resp => {     console.log(resp.docs)     let batch = this.afs.firestore.batch();      resp.docs.forEach(userDocRef => {       batch.update(userDocRef.ref, {'score': 0, 'leadsWithSalesWin': 0, 'leadsReported': 0});     })     batch.commit().catch(err => console.error(err));   }).catch(error => console.error(error)) }