Cloud Functions: How to copy Firestore Collection to a new document?
I’d like to make a copy of a collection in Firestore upon an event using Cloud Functions
I already have this code that iterates over the collection and copies each document
const firestore = admin.firestore()
firestore.collection("products").get().then(query => {
query.forEach(function(doc) {
var promise = firestore.collection(uid).doc(doc.data().barcode).set(doc.data());
});
});
is there a shorter version? to just copy the whole collection at once?
I wrote a small nodejs snippet for this.
const firebaseAdmin = require('firebase-admin');
const serviceAccount="../../firebase-service-account-key.json";
const firebaseUrl="https://my-app.firebaseio.com";
firebaseAdmin.initializeApp({
credential: firebaseAdmin.credential.cert(require(serviceAccount)),
databaseURL: firebaseUrl
});
const firestore = firebaseAdmin.firestore();
async function copyCollection(srcCollectionName, destCollectionName) {
const documents = await firestore.collection(srcCollectionName).get();
let writeBatch = firebaseAdmin.firestore().batch();
const destCollection = firestore.collection(destCollectionName);
let i = 0;
for (const doc of documents.docs) {
writeBatch.set(destCollection.doc(doc.id), doc.data());
i++;
if (i > 400) { // write batch only allows maximum 500 writes per batch
i = 0;
console.log('Intermediate committing of batch operation');
await writeBatch.commit();
writeBatch = firebaseAdmin.firestore().batch();
}
}
if (i > 0) {
console.log('Firebase batch operation completed. Doing final committing of batch operation.');
await writeBatch.commit();
} else {
console.log('Firebase batch operation completed.');
}
}
copyCollection('customers', 'customers_backup').then(() => console.log('copy complete')).catch(error => console.log('copy failed. ' + error));
Currently, no. Looping through each document using Cloud Functions and then setting a new document to a different collection with the specified data is the only way to do this. Perhaps this would make a good feature request.
How many documents are we talking about? For something like 10,000 it should only take a few minutes, tops.
This is the method i use to copy data to another collection, I used it to shift data (like sells or something) from an active collection to a ‘sells feed’ or ‘sells history’ collection.
At the top i reference the documents, at the bottom is the quite compact code.
You can simply add a for loop on top for more than 1 operation.
Hope it helps somebody 🙂
DocumentReference copyFrom = FirebaseFirestore.instance.collection('curSells').doc('0001');
DocumentReference copyTo = FirebaseFirestore.instance.collection('sellFeed').doc('0001');
copyFrom.get().then((value) => {
copyTo.set(value.data())
});
There is no fast way at the moment. I recommend you rewrite your code like this though:
import { firestore } from "firebase-admin";
async function copyCollection() {
const products = await firestore().collection("products").get();
products.forEach(async (doc)=> {
await firestore().collection(uid).doc(doc.get('barcode')).set(doc.data());
})
}
