There are several ways to write data to Cloud Firestore:
- Set the data of a document within a collection, explicitly specifying a document identifier.
- Add a new document to a collection. In this case, Cloud Firestore automatically generates the document identifier.
- Create an empty document with an automatically generated identifier, and assign data to it later.
This guide explains how to use the set, add, or update individual documents in Cloud Firestore. If you want to write data in bulk, see Transactions and Batched Writes.
Before you begin
See Get started with Cloud Firestore to create a Cloud Firestore database.Initialize Cloud Firestore
Initialize an instance of Cloud Firestore:
Web modular API
import { initializeApp } from "firebase/app"; import { getFirestore } from "firebase/firestore"; // TODO: Replace the following with your app's Firebase project configuration // See: https://support.google.com/firebase/answer/7015592 const firebaseConfig = { FIREBASE_CONFIGURATION }; // Initialize Firebase const app = initializeApp(firebaseConfig); // Initialize Cloud Firestore and get a reference to the service const db = getFirestore(app);
Replace FIREBASE_CONFIGURATION with your web app's
firebaseConfig
.
To persist data when the device loses its connection, see the Enable Offline Data documentation.
Web namespaced API
import firebase from "firebase/app"; import "firebase/firestore"; // TODO: Replace the following with your app's Firebase project configuration // See: https://support.google.com/firebase/answer/7015592 const firebaseConfig = { FIREBASE_CONFIGURATION }; // Initialize Firebase firebase.initializeApp(firebaseConfig); // Initialize Cloud Firestore and get a reference to the service const db = firebase.firestore();
Replace FIREBASE_CONFIGURATION with your web app's
firebaseConfig
.
To persist data when the device loses its connection, see the Enable Offline Data documentation.
Swift
import FirebaseCore import FirebaseFirestore
FirebaseApp.configure() let db = Firestore.firestore()
Objective-C
@import FirebaseCore; @import FirebaseFirestore; // Use Firebase library to configure APIs [FIRApp configure];
FIRFirestore *defaultFirestore = [FIRFirestore firestore];
Kotlin+KTX
// Access a Cloud Firestore instance from your Activity
val db = Firebase.firestore
Java
// Access a Cloud Firestore instance from your Activity
FirebaseFirestore db = FirebaseFirestore.getInstance();
Dart
db = FirebaseFirestore.instance;
Java
The Cloud Firestore SDK is initialized in different ways depending on your environment. Below are the most common methods. For a complete reference, see Initialize the Admin SDK.import com.google.auth.oauth2.GoogleCredentials; import com.google.cloud.firestore.Firestore; import com.google.firebase.FirebaseApp; import com.google.firebase.FirebaseOptions; // Use the application default credentials GoogleCredentials credentials = GoogleCredentials.getApplicationDefault(); FirebaseOptions options = new FirebaseOptions.Builder() .setCredentials(credentials) .setProjectId(projectId) .build(); FirebaseApp.initializeApp(options); Firestore db = FirestoreClient.getFirestore();
To use the Firebase Admin SDK on your own server, use a service account.
Go to IAM & admin > Service accounts in the Google Cloud console. Generate a new private key and save the JSON file. Then use the file to initialize the SDK:
import com.google.auth.oauth2.GoogleCredentials; import com.google.cloud.firestore.Firestore; import com.google.firebase.FirebaseApp; import com.google.firebase.FirebaseOptions; // Use a service account InputStream serviceAccount = new FileInputStream("path/to/serviceAccount.json"); GoogleCredentials credentials = GoogleCredentials.fromStream(serviceAccount); FirebaseOptions options = new FirebaseOptions.Builder() .setCredentials(credentials) .build(); FirebaseApp.initializeApp(options); Firestore db = FirestoreClient.getFirestore();
Python
The Cloud Firestore SDK is initialized in different ways depending on your environment. Below are the most common methods. For a complete reference, see Initialize the Admin SDK.import firebase_admin from firebase_admin import firestore # Application Default credentials are automatically created. app = firebase_admin.initialize_app() db = firestore.client()
An existing application default credential can also be used to initialize the SDK.
import firebase_admin from firebase_admin import credentials from firebase_admin import firestore # Use the application default credentials. cred = credentials.ApplicationDefault() firebase_admin.initialize_app(cred) db = firestore.client()
To use the Firebase Admin SDK on your own server, use a service account.
Go to IAM & admin > Service accounts in the Google Cloud console. Generate a new private key and save the JSON file. Then use the file to initialize the SDK:
import firebase_admin from firebase_admin import credentials from firebase_admin import firestore # Use a service account. cred = credentials.Certificate('path/to/serviceAccount.json') app = firebase_admin.initialize_app(cred) db = firestore.client()
Python
The Cloud Firestore SDK is initialized in different ways depending on your environment. Below are the most common methods. For a complete reference, see Initialize the Admin SDK.import firebase_admin from firebase_admin import firestore_async # Application Default credentials are automatically created. app = firebase_admin.initialize_app() db = firestore_async.client()
An existing application default credential can also be used to initialize the SDK.
import firebase_admin from firebase_admin import credentials from firebase_admin import firestore_async # Use the application default credentials. cred = credentials.ApplicationDefault() firebase_admin.initialize_app(cred) db = firestore_async.client()
To use the Firebase Admin SDK on your own server, use a service account.
Go to IAM & admin > Service accounts in the Google Cloud console. Generate a new private key and save the JSON file. Then use the file to initialize the SDK:
import firebase_admin from firebase_admin import credentials from firebase_admin import firestore_async # Use a service account. cred = credentials.Certificate('path/to/serviceAccount.json') app = firebase_admin.initialize_app(cred) db = firestore_async.client()
C++
// Make sure the call to `Create()` happens some time before you call Firestore::GetInstance(). App::Create(); Firestore* db = Firestore::GetInstance();
Node.js
The Cloud Firestore SDK is initialized in different ways depending on your environment. Below are the most common methods. For a complete reference, see Initialize the Admin SDK.-
Initialize on Cloud Functions
const { initializeApp, applicationDefault, cert } = require('firebase-admin/app'); const { getFirestore, Timestamp, FieldValue, Filter } = require('firebase-admin/firestore');
initializeApp(); const db = getFirestore();
-
Initialize on Google Cloud
const { initializeApp, applicationDefault, cert } = require('firebase-admin/app'); const { getFirestore, Timestamp, FieldValue, Filter } = require('firebase-admin/firestore');
initializeApp({ credential: applicationDefault() }); const db = getFirestore();
-
Initialize on your own server
To use the Firebase Admin SDK on your own server (or any other Node.js environment), use a service account. Go to IAM & admin > Service accounts in the Google Cloud console. Generate a new private key and save the JSON file. Then use the file to initialize the SDK:
const { initializeApp, applicationDefault, cert } = require('firebase-admin/app'); const { getFirestore, Timestamp, FieldValue, Filter } = require('firebase-admin/firestore');
const serviceAccount = require('./path/to/serviceAccountKey.json'); initializeApp({ credential: cert(serviceAccount) }); const db = getFirestore();
Go
The Cloud Firestore SDK is initialized in different ways depending on your environment. Below are the most common methods. For a complete reference, see Initialize the Admin SDK.import ( "log" firebase "firebase.google.com/go" "google.golang.org/api/option" ) // Use the application default credentials ctx := context.Background() conf := &firebase.Config{ProjectID: projectID} app, err := firebase.NewApp(ctx, conf) if err != nil { log.Fatalln(err) } client, err := app.Firestore(ctx) if err != nil { log.Fatalln(err) } defer client.Close()
To use the Firebase Admin SDK on your own server, use a service account.
Go to IAM & admin > Service accounts in the Google Cloud console. Generate a new private key and save the JSON file. Then use the file to initialize the SDK:
import ( "log" firebase "firebase.google.com/go" "google.golang.org/api/option" ) // Use a service account ctx := context.Background() sa := option.WithCredentialsFile("path/to/serviceAccount.json") app, err := firebase.NewApp(ctx, nil, sa) if err != nil { log.Fatalln(err) } client, err := app.Firestore(ctx) if err != nil { log.Fatalln(err) } defer client.Close()
PHP
PHP
For more on installing and creating a Cloud Firestore client, refer to Cloud Firestore Client Libraries.
Unity
using Firebase.Firestore; using Firebase.Extensions;
FirebaseFirestore db = FirebaseFirestore.DefaultInstance;
C#
C#
For more on installing and creating a Cloud Firestore client, refer to Cloud Firestore Client Libraries.
Ruby
Set a document
To create or overwrite a single document, use the following language-specific set()
methods:
Web modular API
Use the setDoc()
method:
import { doc, setDoc } from "firebase/firestore"; // Add a new document in collection "cities" await setDoc(doc(db, "cities", "LA"), { name: "Los Angeles", state: "CA", country: "USA" });
Web namespaced API
Use the set()
method:
// Add a new document in collection "cities" db.collection("cities").doc("LA").set({ name: "Los Angeles", state: "CA", country: "USA" }) .then(() => { console.log("Document successfully written!"); }) .catch((error) => { console.error("Error writing document: ", error); });
Swift
Use the setData()
method:
// Add a new document in collection "cities" db.collection("cities").document("LA").setData([ "name": "Los Angeles", "state": "CA", "country": "USA" ]) { err in if let err = err { print("Error writing document: \(err)") } else { print("Document successfully written!") } }
Objective-C
Use the setData:
method:
// Add a new document in collection "cities" [[[self.db collectionWithPath:@"cities"] documentWithPath:@"LA"] setData:@{ @"name": @"Los Angeles", @"state": @"CA", @"country": @"USA" } completion:^(NSError * _Nullable error) { if (error != nil) { NSLog(@"Error writing document: %@", error); } else { NSLog(@"Document successfully written!"); } }];
Kotlin+KTX
Use the set()
method:
val city = hashMapOf( "name" to "Los Angeles", "state" to "CA", "country" to "USA", ) db.collection("cities").document("LA") .set(city) .addOnSuccessListener { Log.d(TAG, "DocumentSnapshot successfully written!") } .addOnFailureListener { e -> Log.w(TAG, "Error writing document", e) }
Java
Use the set()
method:
Map<String, Object> city = new HashMap<>(); city.put("name", "Los Angeles"); city.put("state", "CA"); city.put("country", "USA"); db.collection("cities").document("LA") .set(city) .addOnSuccessListener(new OnSuccessListener<Void>() { @Override public void onSuccess(Void aVoid) { Log.d(TAG, "DocumentSnapshot successfully written!"); } }) .addOnFailureListener(new OnFailureListener() { @Override public void onFailure(@NonNull Exception e) { Log.w(TAG, "Error writing document", e); } });
Dart
Use the set()
method:
final city = <String, String>{ "name": "Los Angeles", "state": "CA", "country": "USA" }; db .collection("cities") .doc("LA") .set(city) .onError((e, _) => print("Error writing document: $e"));
Java
Use the set()
method:
Python
Use the set()
method:
Python
Use the set()
method:
C++
Use the Set()
method:
// Add a new document in collection 'cities' db->Collection("cities") .Document("LA") .Set({{"name", FieldValue::String("Los Angeles")}, {"state", FieldValue::String("CA")}, {"country", FieldValue::String("USA")}}) .OnCompletion([](const Future<void>& future) { if (future.error() == Error::kErrorOk) { std::cout << "DocumentSnapshot successfully written!" << std::endl; } else { std::cout << "Error writing document: " << future.error_message() << std::endl; } });
Node.js
Use the set()
method:
Go
Use the Set()
method:
PHP
Use the set()
method:
PHP
For more on installing and creating a Cloud Firestore client, refer to Cloud Firestore Client Libraries.
Unity
Use the SetAsync()
method:
DocumentReference docRef = db.Collection("cities").Document("LA"); Dictionary<string, object> city = new Dictionary<string, object> { { "Name", "Los Angeles" }, { "State", "CA" }, { "Country", "USA" } }; docRef.SetAsync(city).ContinueWithOnMainThread(task => { Debug.Log("Added data to the LA document in the cities collection."); });
C#
Use the SetAsync()
method:
Ruby
Use the set()
method:
If the document does not exist, it will be created. If the document does exist, its contents will be overwritten with the newly provided data, unless you specify that the data should be merged into the existing document, as follows:
Web modular API
import { doc, setDoc } from "firebase/firestore"; const cityRef = doc(db, 'cities', 'BJ'); setDoc(cityRef, { capital: true }, { merge: true });
Web namespaced API
var cityRef = db.collection('cities').doc('BJ'); var setWithMerge = cityRef.set({ capital: true }, { merge: true });
Swift
// Update one field, creating the document if it does not exist. db.collection("cities").document("BJ").setData([ "capital": true ], merge: true)
Objective-C
// Write to the document reference, merging data with existing // if the document already exists [[[self.db collectionWithPath:@"cities"] documentWithPath:@"BJ"] setData:@{ @"capital": @YES } merge:YES completion:^(NSError * _Nullable error) { // ... }];
Kotlin+KTX
// Update one field, creating the document if it does not already exist. val data = hashMapOf("capital" to true) db.collection("cities").document("BJ") .set(data, SetOptions.merge())
Java
// Update one field, creating the document if it does not already exist. Map<String, Object> data = new HashMap<>(); data.put("capital", true); db.collection("cities").document("BJ") .set(data, SetOptions.merge());
Dart
// Update one field, creating the document if it does not already exist. final data = {"capital": true}; db.collection("cities").doc("BJ").set(data, SetOptions(merge: true));
Java
Python
Python
C++
db->Collection("cities").Document("BJ").Set( {{"capital", FieldValue::Boolean(true)}}, SetOptions::Merge());
Node.js
Go
PHP
PHP
For more on installing and creating a Cloud Firestore client, refer to Cloud Firestore Client Libraries.
Unity
DocumentReference docRef = db.Collection("cities").Document("LA"); Dictionary<string, object> update = new Dictionary<string, object> { { "capital", false } }; docRef.SetAsync(update, SetOptions.MergeAll);
C#
Ruby
If you're not sure whether the document exists, pass the option to merge the new data with any existing document to avoid overwriting entire documents. For documents containing maps, note that specifying a set with a field containing an empty map will overwrite the target document's map field.
Data types
Cloud Firestore lets you write a variety of data types inside a document, including strings, booleans, numbers, dates, null, and nested arrays and objects. Cloud Firestore always stores numbers as doubles, regardless of what type of number you use in your code.
Web modular API
import { doc, setDoc, Timestamp } from "firebase/firestore"; const docData = { stringExample: "Hello world!", booleanExample: true, numberExample: 3.14159265, dateExample: Timestamp.fromDate(new Date("December 10, 1815")), arrayExample: [5, true, "hello"], nullExample: null, objectExample: { a: 5, b: { nested: "foo" } } }; await setDoc(doc(db, "data", "one"), docData);
Web namespaced API
var docData = { stringExample: "Hello world!", booleanExample: true, numberExample: 3.14159265, dateExample: firebase.firestore.Timestamp.fromDate(new Date("December 10, 1815")), arrayExample: [5, true, "hello"], nullExample: null, objectExample: { a: 5, b: { nested: "foo" } } }; db.collection("data").doc("one").set(docData).then(() => { console.log("Document successfully written!"); });
Swift
let docData: [String: Any] = [ "stringExample": "Hello world!", "booleanExample": true, "numberExample": 3.14159265, "dateExample": Timestamp(date: Date()), "arrayExample": [5, true, "hello"], "nullExample": NSNull(), "objectExample": [ "a": 5, "b": [ "nested": "foo" ] ] ] db.collection("data").document("one").setData(docData) { err in if let err = err { print("Error writing document: \(err)") } else { print("Document successfully written!") } }
Objective-C
NSDictionary *docData = @{ @"stringExample": @"Hello world!", @"booleanExample": @YES, @"numberExample": @3.14, @"dateExample": [FIRTimestamp timestampWithDate:[NSDate date]], @"arrayExample": @[@5, @YES, @"hello"], @"nullExample": [NSNull null], @"objectExample": @{ @"a": @5, @"b": @{ @"nested": @"foo" } } }; [[[self.db collectionWithPath:@"data"] documentWithPath:@"one"] setData:docData completion:^(NSError * _Nullable error) { if (error != nil) { NSLog(@"Error writing document: %@", error); } else { NSLog(@"Document successfully written!"); } }];
Kotlin+KTX
val docData = hashMapOf( "stringExample" to "Hello world!", "booleanExample" to true, "numberExample" to 3.14159265, "dateExample" to Timestamp(Date()), "listExample" to arrayListOf(1, 2, 3), "nullExample" to null, ) val nestedData = hashMapOf( "a" to 5, "b" to true, ) docData["objectExample"] = nestedData db.collection("data").document("one") .set(docData) .addOnSuccessListener { Log.d(TAG, "DocumentSnapshot successfully written!") } .addOnFailureListener { e -> Log.w(TAG, "Error writing document", e) }
Java
Map<String, Object> docData = new HashMap<>(); docData.put("stringExample", "Hello world!"); docData.put("booleanExample", true); docData.put("numberExample", 3.14159265); docData.put("dateExample", new Timestamp(new Date())); docData.put("listExample", Arrays.asList(1, 2, 3)); docData.put("nullExample", null); Map<String, Object> nestedData = new HashMap<>(); nestedData.put("a", 5); nestedData.put("b", true); docData.put("objectExample", nestedData); db.collection("data").document("one") .set(docData) .addOnSuccessListener(new OnSuccessListener<Void>() { @Override public void onSuccess(Void aVoid) { Log.d(TAG, "DocumentSnapshot successfully written!"); } }) .addOnFailureListener(new OnFailureListener() { @Override public void onFailure(@NonNull Exception e) { Log.w(TAG, "Error writing document", e); } });
Dart
final docData = { "stringExample": "Hello world!", "booleanExample": true, "numberExample": 3.14159265, "dateExample": Timestamp.now(), "listExample": [1, 2, 3], "nullExample": null }; final nestedData = { "a": 5, "b": true, }; docData["objectExample"] = nestedData; db .collection("data") .doc("one") .set(docData) .onError((e, _) => print("Error writing document: $e"));
Java
Python
Python
C++
MapFieldValue doc_data{ {"stringExample", FieldValue::String("Hello world!")}, {"booleanExample", FieldValue::Boolean(true)}, {"numberExample", FieldValue::Double(3.14159265)}, {"dateExample", FieldValue::Timestamp(Timestamp::Now())}, {"arrayExample", FieldValue::Array({FieldValue::Integer(1), FieldValue::Integer(2), FieldValue::Integer(3)})}, {"nullExample", FieldValue::Null()}, {"objectExample", FieldValue::Map( {{"a", FieldValue::Integer(5)}, {"b", FieldValue::Map( {{"nested", FieldValue::String("foo")}})}})}, }; db->Collection("data").Document("one").Set(doc_data).OnCompletion( [](const Future<void>& future) { if (future.error() == Error::kErrorOk) { std::cout << "DocumentSnapshot successfully written!" << std::endl; } else { std::cout << "Error writing document: " << future.error_message() << std::endl; } });
Node.js
Go
PHP
PHP
For more on installing and creating a Cloud Firestore client, refer to Cloud Firestore Client Libraries.
Unity
DocumentReference docRef = db.Collection("data").Document("one"); Dictionary<string, object> docData = new Dictionary<string, object> { { "stringExample", "Hello World" }, { "booleanExample", false }, { "numberExample", 3.14159265 }, { "nullExample", null }, { "arrayExample", new List<object>() { 5, true, "Hello" } }, { "objectExample", new Dictionary<string, object> { { "a", 5 }, { "b", true }, } }, }; docRef.SetAsync(docData);
C#
Ruby
Custom objects
Using Map
or Dictionary
objects to represent your documents is often not
very convenient, so Cloud Firestore supports writing documents with
custom classes. Cloud Firestore converts the objects to supported data
types.
Using custom classes, you could rewrite the initial example as shown:
Web modular API
class City { constructor (name, state, country ) { this.name = name; this.state = state; this.country = country; } toString() { return this.name + ', ' + this.state + ', ' + this.country; } } // Firestore data converter const cityConverter = { toFirestore: (city) => { return { name: city.name, state: city.state, country: city.country }; }, fromFirestore: (snapshot, options) => { const data = snapshot.data(options); return new City(data.name, data.state, data.country); } };
Web namespaced API
class City { constructor (name, state, country ) { this.name = name; this.state = state; this.country = country; } toString() { return this.name + ', ' + this.state + ', ' + this.country; } } // Firestore data converter var cityConverter = { toFirestore: function(city) { return { name: city.name, state: city.state, country: city.country }; }, fromFirestore: function(snapshot, options){ const data = snapshot.data(options); return new City(data.name, data.state, data.country); } };
Swift
public struct City: Codable { let name: String let state: String? let country: String? let isCapital: Bool? let population: Int64? enum CodingKeys: String, CodingKey { case name case state case country case isCapital = "capital" case population } }
Objective-C
// This isn't supported in Objective-C.
Kotlin+KTX
data class City( val name: String? = null, val state: String? = null, val country: String? = null, @field:JvmField // use this annotation if your Boolean field is prefixed with 'is' val isCapital: Boolean? = null, val population: Long? = null, val regions: List<String>? = null, )
Java
Each custom class must have a public constructor that takes no arguments. In addition, the class must include a public getter for each property.
public class City { private String name; private String state; private String country; private boolean capital; private long population; private List<String> regions; public City() {} public City(String name, String state, String country, boolean capital, long population, List<String> regions) { // ... } public String getName() { return name; } public String getState() { return state; } public String getCountry() { return country; } public boolean isCapital() { return capital; } public long getPopulation() { return population; } public List<String> getRegions() { return regions; } }
Dart
class City { final String? name; final String? state; final String? country; final bool? capital; final int? population; final List<String>? regions; City({ this.name, this.state, this.country, this.capital, this.population, this.regions, }); factory City.fromFirestore( DocumentSnapshot<Map<String, dynamic>> snapshot, SnapshotOptions? options, ) { final data = snapshot.data(); return City( name: data?['name'], state: data?['state'], country: data?['country'], capital: data?['capital'], population: data?['population'], regions: data?['regions'] is Iterable ? List.from(data?['regions']) : null, ); } Map<String, dynamic> toFirestore() { return { if (name != null) "name": name, if (state != null) "state": state, if (country != null) "country": country, if (capital != null) "capital": capital, if (population != null) "population": population, if (regions != null) "regions": regions, }; } }
Java
Python
Python
C++
// This is not yet supported.
Node.js
// Node.js uses JavaScript objects
Go
PHP
PHP
For more on installing and creating a Cloud Firestore client, refer to Cloud Firestore Client Libraries.
Unity
[FirestoreData] public class City { [FirestoreProperty] public string Name { get; set; } [FirestoreProperty] public string State { get; set; } [FirestoreProperty] public string Country { get; set; } [FirestoreProperty] public bool Capital { get; set; } [FirestoreProperty] public long Population { get; set; } }
C#
Ruby
// This isn't supported in Ruby
Web modular API
import { doc, setDoc } from "firebase/firestore"; // Set with cityConverter const ref = doc(db, "cities", "LA").withConverter(cityConverter); await setDoc(ref, new City("Los Angeles", "CA", "USA"));
Web namespaced API
// Set with cityConverter db.collection("cities").doc("LA") .withConverter(cityConverter) .set(new City("Los Angeles", "CA", "USA"));
Swift
let city = City(name: "Los Angeles", state: "CA", country: "USA", isCapital: false, population: 5000000) do { try db.collection("cities").document("LA").setData(from: city) } catch let error { print("Error writing city to Firestore: \(error)") }
Objective-C
// This isn't supported in Objective-C.
Kotlin+KTX
val city = City( "Los Angeles", "CA", "USA", false, 5000000L, listOf("west_coast", "socal"), ) db.collection("cities").document("LA").set(city)
Java
City city = new City("Los Angeles", "CA", "USA", false, 5000000L, Arrays.asList("west_coast", "sorcal")); db.collection("cities").document("LA").set(city);
Dart
final city = City( name: "Los Angeles", state: "CA", country: "USA", capital: false, population: 5000000, regions: ["west_coast", "socal"], ); final docRef = db .collection("cities") .withConverter( fromFirestore: City.fromFirestore, toFirestore: (City city, options) => city.toFirestore(), ) .doc("LA"); await docRef.set(city);
Java
Python
Python
C++
// This is not yet supported.
Node.js
// Node.js uses JavaScript objects
Go
PHP
// This isn't supported in PHP.
Unity
DocumentReference docRef = db.Collection("cities").Document("LA"); City city = new City { Name = "Los Angeles", State = "CA", Country = "USA", Capital = false, Population = 3900000L }; docRef.SetAsync(city);
C#
Ruby
// This isn't supported in Ruby.
Add a document
When you use set()
to create a document, you must specify an ID for the
document to create. For example:
Web modular API
import { doc, setDoc } from "firebase/firestore"; await setDoc(doc(db, "cities", "new-city-id"), data);
Web namespaced API
db.collection("cities").doc("new-city-id").set(data);
Swift
db.collection("cities").document("new-city-id").setData(data)
Objective-C
[[[self.db collectionWithPath:@"cities"] documentWithPath:@"new-city-id"] setData:data];
Kotlin+KTX
db.collection("cities").document("new-city-id").set(data)
Java
db.collection("cities").document("new-city-id").set(data);
Dart
db.collection("cities").doc("new-city-id").set({"name": "Chicago"});
Java
Python
Python
C++
db->Collection("cities").Document("SF").Set({/*some data*/});
Node.js
Go
PHP
PHP
For more on installing and creating a Cloud Firestore client, refer to Cloud Firestore Client Libraries.
Unity
db.Collection("cities").Document("new-city-id").SetAsync(city);
C#
Ruby
But sometimes there isn't a meaningful ID for the document, and it's more
convenient to let Cloud Firestore auto-generate an ID for you. You can do
this by calling the following language-specific add()
methods:
Web modular API
Use the addDoc()
method:
import { collection, addDoc } from "firebase/firestore"; // Add a new document with a generated id. const docRef = await addDoc(collection(db, "cities"), { name: "Tokyo", country: "Japan" }); console.log("Document written with ID: ", docRef.id);
Web namespaced API
Use the add()
method:
// Add a new document with a generated id. db.collection("cities").add({ name: "Tokyo", country: "Japan" }) .then((docRef) => { console.log("Document written with ID: ", docRef.id); }) .catch((error) => { console.error("Error adding document: ", error); });
Swift
Use the addDocument()
method:
// Add a new document with a generated id. var ref: DocumentReference? = nil ref = db.collection("cities").addDocument(data: [ "name": "Tokyo", "country": "Japan" ]) { err in if let err = err { print("Error adding document: \(err)") } else { print("Document added with ID: \(ref!.documentID)") } }
Objective-C
Use the addDocumentWithData:
method:
// Add a new document with a generated id. __block FIRDocumentReference *ref = [[self.db collectionWithPath:@"cities"] addDocumentWithData:@{ @"name": @"Tokyo", @"country": @"Japan" } completion:^(NSError * _Nullable error) { if (error != nil) { NSLog(@"Error adding document: %@", error); } else { NSLog(@"Document added with ID: %@", ref.documentID); } }];
Kotlin+KTX
Use the add()
method:
// Add a new document with a generated id. val data = hashMapOf( "name" to "Tokyo", "country" to "Japan", ) db.collection("cities") .add(data) .addOnSuccessListener { documentReference -> Log.d(TAG, "DocumentSnapshot written with ID: ${documentReference.id}") } .addOnFailureListener { e -> Log.w(TAG, "Error adding document", e) }
Java
Use the add()
method:
// Add a new document with a generated id. Map<String, Object> data = new HashMap<>(); data.put("name", "Tokyo"); data.put("country", "Japan"); db.collection("cities") .add(data) .addOnSuccessListener(new OnSuccessListener<DocumentReference>() { @Override public void onSuccess(DocumentReference documentReference) { Log.d(TAG, "DocumentSnapshot written with ID: " + documentReference.getId()); } }) .addOnFailureListener(new OnFailureListener() { @Override public void onFailure(@NonNull Exception e) { Log.w(TAG, "Error adding document", e); } });
Dart
Use the add()
method:
// Add a new document with a generated id. final data = {"name": "Tokyo", "country": "Japan"}; db.collection("cities").add(data).then((documentSnapshot) => print("Added Data with ID: ${documentSnapshot.id}"));
Java
Use the add()
method:
Python
Use the add()
method:
Python
Use the add()
method:
C++
Use the Add()
method:
db->Collection("cities").Add({/*some data*/});
Node.js
Use the add()
method:
Go
Use the Add()
method:
PHP
Use the add()
method:
PHP
For more on installing and creating a Cloud Firestore client, refer to Cloud Firestore Client Libraries.
Unity
Use the AddAsync()
method:
Dictionary<string, object> city = new Dictionary<string, object> { { "Name", "Tokyo" }, { "Country", "Japan" } }; db.Collection("cities").AddAsync(city).ContinueWithOnMainThread(task => { DocumentReference addedDocRef = task.Result; Debug.Log(String.Format("Added document with ID: {0}.", addedDocRef.Id)); });
C#
Use the AddAsync()
method:
Ruby
Use the add()
method:
In some cases, it can be useful to create a document reference with an
auto-generated ID, then use the reference later. For this use case, you can call
doc()
:
Web modular API
import { collection, doc, setDoc } from "firebase/firestore"; // Add a new document with a generated id const newCityRef = doc(collection(db, "cities")); // later... await setDoc(newCityRef, data);
Web namespaced API
// Add a new document with a generated id. var newCityRef = db.collection("cities").doc(); // later... newCityRef.set(data);
Swift
let newCityRef = db.collection("cities").document() // later... newCityRef.setData([ // ... ])
Objective-C
FIRDocumentReference *newCityRef = [[self.db collectionWithPath:@"cities"] documentWithAutoID]; // later... [newCityRef setData:@{ /* ... */ }];
Kotlin+KTX
val data = HashMap<String, Any>() val newCityRef = db.collection("cities").document() // Later... newCityRef.set(data)
Java
Map<String, Object> data = new HashMap<>(); DocumentReference newCityRef = db.collection("cities").document(); // Later... newCityRef.set(data);
Dart
// Add a new document with a generated id. final data = <String, dynamic>{}; final newCityRef = db.collection("cities").doc(); // Later... newCityRef.set(data);
Java
Python
Python
C++
DocumentReference new_city_ref = db->Collection("cities").Document();
Node.js
Go
PHP
PHP
For more on installing and creating a Cloud Firestore client, refer to Cloud Firestore Client Libraries.
Unity
DocumentReference addedDocRef = db.Collection("cities").Document(); Debug.Log(String.Format("Added document with ID: {0}.", addedDocRef.Id)); addedDocRef.SetAsync(city).ContinueWithOnMainThread(task => { Debug.Log(String.Format( "Added data to the {0} document in the cities collection.", addedDocRef.Id)); });
C#
Ruby
Behind the scenes, .add(...)
and .doc().set(...)
are completely
equivalent, so you can use whichever is more convenient.
Update a document
To update some fields of a document without overwriting the entire document, use
the following language-specific update()
methods:
Web modular API
Use the updateDoc()
method:
import { doc, updateDoc } from "firebase/firestore"; const washingtonRef = doc(db, "cities", "DC"); // Set the "capital" field of the city 'DC' await updateDoc(washingtonRef, { capital: true });
Web namespaced API
Use the update()
method:
var washingtonRef = db.collection("cities").doc("DC"); // Set the "capital" field of the city 'DC' return washingtonRef.update({ capital: true }) .then(() => { console.log("Document successfully updated!"); }) .catch((error) => { // The document probably doesn't exist. console.error("Error updating document: ", error); });
Swift
Use the updateData()
method:
let washingtonRef = db.collection("cities").document("DC") // Set the "capital" field of the city 'DC' washingtonRef.updateData([ "capital": true ]) { err in if let err = err { print("Error updating document: \(err)") } else { print("Document successfully updated") } }
Objective-C
Use the updateData:
method:
FIRDocumentReference *washingtonRef = [[self.db collectionWithPath:@"cities"] documentWithPath:@"DC"]; // Set the "capital" field of the city [washingtonRef updateData:@{ @"capital": @YES } completion:^(NSError * _Nullable error) { if (error != nil) { NSLog(@"Error updating document: %@", error); } else { NSLog(@"Document successfully updated"); } }];
Kotlin+KTX
Use the update()
method:
val washingtonRef = db.collection("cities").document("DC") // Set the "isCapital" field of the city 'DC' washingtonRef .update("capital", true) .addOnSuccessListener { Log.d(TAG, "DocumentSnapshot successfully updated!") } .addOnFailureListener { e -> Log.w(TAG, "Error updating document", e) }
Java
Use the update()
method:
DocumentReference washingtonRef = db.collection("cities").document("DC"); // Set the "isCapital" field of the city 'DC' washingtonRef .update("capital", true) .addOnSuccessListener(new OnSuccessListener<Void>() { @Override public void onSuccess(Void aVoid) { Log.d(TAG, "DocumentSnapshot successfully updated!"); } }) .addOnFailureListener(new OnFailureListener() { @Override public void onFailure(@NonNull Exception e) { Log.w(TAG, "Error updating document", e); } });
Dart
Use the update()
method:
final washingtonRef = db.collection("cites").doc("DC"); washingtonRef.update({"capital": true}).then( (value) => print("DocumentSnapshot successfully updated!"), onError: (e) => print("Error updating document $e"));
Java
Use the update()
method:
Python
Use the update()
method:
Python
Use the update()
method:
C++
Use the Update()
method:
DocumentReference washington_ref = db->Collection("cities").Document("DC"); // Set the "capital" field of the city "DC". washington_ref.Update({{"capital", FieldValue::Boolean(true)}});
Node.js
Use the update()
method:
Go
Use the Update()
method:
PHP
Use the update()
method:
PHP
For more on installing and creating a Cloud Firestore client, refer to Cloud Firestore Client Libraries.
Unity
Use the UpdateAsync()
method:
DocumentReference cityRef = db.Collection("cities").Document("new-city-id"); Dictionary<string, object> updates = new Dictionary<string, object> { { "Capital", false } }; cityRef.UpdateAsync(updates).ContinueWithOnMainThread(task => { Debug.Log( "Updated the Capital field of the new-city-id document in the cities collection."); }); // You can also update a single field with: cityRef.UpdateAsync("Capital", false);
C#
Use the UpdateAsync()
method:
Ruby
Use the update()
method:
Server Timestamp
You can set a field in your document to a server timestamp which tracks when the server receives the update.
Web modular API
import { updateDoc, serverTimestamp } from "firebase/firestore"; const docRef = doc(db, 'objects', 'some-id'); // Update the timestamp field with the value from the server const updateTimestamp = await updateDoc(docRef, { timestamp: serverTimestamp() });
Web namespaced API
var docRef = db.collection('objects').doc('some-id'); // Update the timestamp field with the value from the server var updateTimestamp = docRef.update({ timestamp: firebase.firestore.FieldValue.serverTimestamp() });
Swift
db.collection("objects").document("some-id").updateData([ "lastUpdated": FieldValue.serverTimestamp(), ]) { err in if let err = err { print("Error updating document: \(err)") } else { print("Document successfully updated") } }
Objective-C
[[[self.db collectionWithPath:@"objects"] documentWithPath:@"some-id"] updateData:@{ @"lastUpdated": [FIRFieldValue fieldValueForServerTimestamp] } completion:^(NSError * _Nullable error) { if (error != nil) { NSLog(@"Error updating document: %@", error); } else { NSLog(@"Document successfully updated"); } }];
Kotlin+KTX
// If you're using custom Kotlin objects in Android, add an @ServerTimestamp // annotation to a Date field for your custom object classes. This indicates // that the Date field should be treated as a server timestamp by the object mapper. val docRef = db.collection("objects").document("some-id") // Update the timestamp field with the value from the server val updates = hashMapOf<String, Any>( "timestamp" to FieldValue.serverTimestamp(), ) docRef.update(updates).addOnCompleteListener { }
Java
// If you're using custom Java objects in Android, add an @ServerTimestamp // annotation to a Date field for your custom object classes. This indicates // that the Date field should be treated as a server timestamp by the object mapper. DocumentReference docRef = db.collection("objects").document("some-id"); // Update the timestamp field with the value from the server Map<String,Object> updates = new HashMap<>(); updates.put("timestamp", FieldValue.serverTimestamp()); docRef.update(updates).addOnCompleteListener(new OnCompleteListener<Void>() { // ... // ...
Dart
final docRef = db.collection("objects").doc("some-id"); final updates = <String, dynamic>{ "timestamp": FieldValue.serverTimestamp(), }; docRef.update(updates).then( (value) => print("DocumentSnapshot successfully updated!"), onError: (e) => print("Error updating document $e"));
Java
Python
Python
C++
DocumentReference doc_ref = db->Collection("objects").Document("some-id"); doc_ref.Update({{"timestamp", FieldValue::ServerTimestamp()}}) .OnCompletion([](const Future<void>& future) { // ... });
Node.js
Go
PHP
PHP
For more on installing and creating a Cloud Firestore client, refer to Cloud Firestore Client Libraries.
Unity
DocumentReference cityRef = db.Collection("cities").Document("new-city-id"); cityRef.UpdateAsync("Timestamp", FieldValue.ServerTimestamp) .ContinueWithOnMainThread(task => { Debug.Log( "Updated the Timestamp field of the new-city-id document in the cities " + "collection."); });
C#
Ruby
When updating multiple timestamp fields inside of a transaction, each field receives the same server timestamp value.
Update fields in nested objects
If your document contains nested objects, you can use "dot notation" to
reference nested fields within the document when you call update()
:
Web modular API
import { doc, setDoc, updateDoc } from "firebase/firestore"; // Create an initial document to update. const frankDocRef = doc(db, "users", "frank"); await setDoc(frankDocRef, { name: "Frank", favorites: { food: "Pizza", color: "Blue", subject: "recess" }, age: 12 }); // To update age and favorite color: await updateDoc(frankDocRef, { "age": 13, "favorites.color": "Red" });
Web namespaced API
// Create an initial document to update. var frankDocRef = db.collection("users").doc("frank"); frankDocRef.set({ name: "Frank", favorites: { food: "Pizza", color: "Blue", subject: "recess" }, age: 12 }); // To update age and favorite color: db.collection("users").doc("frank").update({ "age": 13, "favorites.color": "Red" }) .then(() => { console.log("Document successfully updated!"); });
Swift
// Create an initial document to update. let frankDocRef = db.collection("users").document("frank") frankDocRef.setData([ "name": "Frank", "favorites": [ "food": "Pizza", "color": "Blue", "subject": "recess" ], "age": 12 ]) // To update age and favorite color: db.collection("users").document("frank").updateData([ "age": 13, "favorites.color": "Red" ]) { err in if let err = err { print("Error updating document: \(err)") } else { print("Document successfully updated") } }
Objective-C
// Create an initial document to update. FIRDocumentReference *frankDocRef = [[self.db collectionWithPath:@"users"] documentWithPath:@"frank"]; [frankDocRef setData:@{ @"name": @"Frank", @"favorites": @{ @"food": @"Pizza", @"color": @"Blue", @"subject": @"recess" }, @"age": @12 }]; // To update age and favorite color: [frankDocRef updateData:@{ @"age": @13, @"favorites.color": @"Red", } completion:^(NSError * _Nullable error) { if (error != nil) { NSLog(@"Error updating document: %@", error); } else { NSLog(@"Document successfully updated"); } }];
Kotlin+KTX
// Assume the document contains: // { // name: "Frank", // favorites: { food: "Pizza", color: "Blue", subject: "recess" } // age: 12 // } // // To update age and favorite color: db.collection("users").document("frank") .update( mapOf( "age" to 13, "favorites.color" to "Red", ), )
Java
// Assume the document contains: // { // name: "Frank", // favorites: { food: "Pizza", color: "Blue", subject: "recess" } // age: 12 // } // // To update age and favorite color: db.collection("users").document("frank") .update( "age", 13, "favorites.color", "Red" );
Dart
// Assume the document contains: // { // name: "Frank", // favorites: { food: "Pizza", color: "Blue", subject: "recess" } // age: 12 // } db .collection("users") .doc("frank") .update({"age": 13, "favorites.color": "Red"});
Java
Python
Python
C++
// Assume the document contains: // { // name: "Frank", // favorites: { food: "Pizza", color: "Blue", subject: "recess" } // age: 12 // } // // To update age and favorite color: db->Collection("users").Document("frank").Update({ {"age", FieldValue::Integer(13)}, {"favorites.color", FieldValue::String("red")}, });
Node.js
Go
PHP
PHP
For more on installing and creating a Cloud Firestore client, refer to Cloud Firestore Client Libraries.
Unity
DocumentReference frankDocRef = db.Collection("users").Document("frank"); Dictionary<string, object> initialData = new Dictionary<string, object> { { "Name", "Frank" }, { "Age", 12 } }; Dictionary<string, object> favorites = new Dictionary<string, object> { { "Food", "Pizza" }, { "Color", "Blue" }, { "Subject", "Recess" }, }; initialData.Add("Favorites", favorites); frankDocRef.SetAsync(initialData).ContinueWithOnMainThread(task => { // Update age and favorite color Dictionary<string, object> updates = new Dictionary<string, object> { { "Age", 13 }, { "Favorites.Color", "Red" }, }; // Asynchronously update the document return frankDocRef.UpdateAsync(updates); }).ContinueWithOnMainThread(task => { Debug.Log( "Updated the age and favorite color fields of the Frank document in " + "the users collection."); });
C#
Ruby
Dot notation allows you to update a single nested field without overwriting other nested field. If you update a nested field without dot notation, you will overwrite the entire map field, for example:
Web
// Create our initial doc db.collection("users").doc("frank").set({ name: "Frank", favorites: { food: "Pizza", color: "Blue", subject: "Recess" }, age: 12 }).then(function() { console.log("Frank created"); }); // Update the doc without using dot notation. // Notice the map value for favorites. db.collection("users").doc("frank").update({ favorites: { food: "Ice Cream" } }).then(function() { console.log("Frank food updated"); }); /* Ending State, favorite.color and favorite.subject are no longer present: /users /frank { name: "Frank", favorites: { food: "Ice Cream", }, age: 12 } */
Update elements in an array
If your document contains an array field, you can use arrayUnion()
and
arrayRemove()
to add and remove elements. arrayUnion()
adds elements to an
array but only elements not already present. arrayRemove()
removes all
instances of each given element.
Web modular API
import { doc, updateDoc, arrayUnion, arrayRemove } from "firebase/firestore"; const washingtonRef = doc(db, "cities", "DC"); // Atomically add a new region to the "regions" array field. await updateDoc(washingtonRef, { regions: arrayUnion("greater_virginia") }); // Atomically remove a region from the "regions" array field. await updateDoc(washingtonRef, { regions: arrayRemove("east_coast") });
Web namespaced API
var washingtonRef = db.collection("cities").doc("DC"); // Atomically add a new region to the "regions" array field. washingtonRef.update({ regions: firebase.firestore.FieldValue.arrayUnion("greater_virginia") }); // Atomically remove a region from the "regions" array field. washingtonRef.update({ regions: firebase.firestore.FieldValue.arrayRemove("east_coast") });
Swift
let washingtonRef = db.collection("cities").document("DC") // Atomically add a new region to the "regions" array field. washingtonRef.updateData([ "regions": FieldValue.arrayUnion(["greater_virginia"]) ]) // Atomically remove a region from the "regions" array field. washingtonRef.updateData([ "regions": FieldValue.arrayRemove(["east_coast"]) ])
Objective-C
FIRDocumentReference *washingtonRef = [[self.db collectionWithPath:@"cities"] documentWithPath:@"DC"]; // Atomically add a new region to the "regions" array field. [washingtonRef updateData:@{ @"regions": [FIRFieldValue fieldValueForArrayUnion:@[@"greater_virginia"]] }]; // Atomically remove a new region to the "regions" array field. [washingtonRef updateData:@{ @"regions": [FIRFieldValue fieldValueForArrayRemove:@[@"east_coast"]] }];
Kotlin+KTX
val washingtonRef = db.collection("cities").document("DC") // Atomically add a new region to the "regions" array field. washingtonRef.update("regions", FieldValue.arrayUnion("greater_virginia")) // Atomically remove a region from the "regions" array field. washingtonRef.update("regions", FieldValue.arrayRemove("east_coast"))
Java
DocumentReference washingtonRef = db.collection("cities").document("DC"); // Atomically add a new region to the "regions" array field. washingtonRef.update("regions", FieldValue.arrayUnion("greater_virginia")); // Atomically remove a region from the "regions" array field. washingtonRef.update("regions", FieldValue.arrayRemove("east_coast"));
Dart
final washingtonRef = db.collection("cities").doc("DC"); // Atomically add a new region to the "regions" array field. washingtonRef.update({ "regions": FieldValue.arrayUnion(["greater_virginia"]), }); // Atomically remove a region from the "regions" array field. washingtonRef.update({ "regions": FieldValue.arrayRemove(["east_coast"]), });
Java
Python
Python
C++
// This is not yet supported.
Node.js
Go
// Not supported yet
PHP
PHP
For more on installing and creating a Cloud Firestore client, refer to Cloud Firestore Client Libraries.
Unity
// This is not yet supported in the Unity SDK
C#
Ruby
// Not supported yet
Increment a numeric value
You can increment or decrement a numeric field value as shown in the following example. An increment operation increases or decreases the current value of a field by the given amount.
Web modular API
import { doc, updateDoc, increment } from "firebase/firestore"; const washingtonRef = doc(db, "cities", "DC"); // Atomically increment the population of the city by 50. await updateDoc(washingtonRef, { population: increment(50) });
Web namespaced API
var washingtonRef = db.collection('cities').doc('DC'); // Atomically increment the population of the city by 50. washingtonRef.update({ population: firebase.firestore.FieldValue.increment(50) });
Swift
let washingtonRef = db.collection("cities").document("DC") // Atomically increment the population of the city by 50. // Note that increment() with no arguments increments by 1. washingtonRef.updateData([ "population": FieldValue.increment(Int64(50)) ])
Objective-C
FIRDocumentReference *washingtonRef = [[self.db collectionWithPath:@"cities"] documentWithPath:@"DC"]; // Atomically increment the population of the city by 50. // Note that increment() with no arguments increments by 1. [washingtonRef updateData:@{ @"population": [FIRFieldValue fieldValueForIntegerIncrement:50] }];
Kotlin+KTX
val washingtonRef = db.collection("cities").document("DC") // Atomically increment the population of the city by 50. washingtonRef.update("population", FieldValue.increment(50))
Java
DocumentReference washingtonRef = db.collection("cities").document("DC"); // Atomically increment the population of the city by 50. washingtonRef.update("population", FieldValue.increment(50));
Dart
var washingtonRef = db.collection('cities').doc('DC'); // Atomically increment the population of the city by 50. washingtonRef.update( {"population": FieldValue.increment(50)}, );
Java
Python
Python
C++
// This is not yet supported.
Node.js
Go
PHP
PHP
For more on installing and creating a Cloud Firestore client, refer to Cloud Firestore Client Libraries.
Unity
// This is not yet supported in the Unity SDK.
C#
Ruby
Increment operations are useful for implementing counters, but keep in mind that you can update a single document only once per second. If you need to update your counter above this rate, see the Distributed counters page.