Add Data to Cloud Firestore

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() and add() methods to write data to Cloud Firestore.

Set a document

To create or overwrite a single document, use the set() method:

Web
// Add a new document in collection "cities"
db.collection("cities").doc("LA").set({
    name: "Los Angeles",
    state: "CA",
    country: "USA"
})
.then(function() {
    console.log("Document successfully written!");
})
.catch(function(error) {
    console.error("Error writing document: ", error);
});
Swift
// 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
// 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!");
  }
}];
  
Android
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);
            }
        });
Java
// Create a Map to store the data we want to set
Map<String, Object> docData = new HashMap<>();
docData.put("name", "Los Angeles");
docData.put("state", "CA");
docData.put("country", "USA");
// Add a new document (asynchronously) in collection "cities" with id "LA"
ApiFuture<WriteResult> future = db.collection("cities").document("LA").set(docData);
// ...
// future.get() blocks on response
System.out.println("Update time : " + future.get().getUpdateTime());
Python
data = {
    u'name': u'Los Angeles',
    u'state': u'CA',
    u'country': u'USA'
}

# Add a new doc in collection 'cities' with ID 'LA'
db.collection(u'cities').document(u'LA').set(data)
Node.js
var data = {
    name: 'Los Angeles',
    state: 'CA',
    country: 'USA'
};

// Add a new document in collection "cities" with ID 'DC'
var setDoc = db.collection('cities').doc('LA').set(data);
Go
_, err := client.Collection("cities").Doc("LA").Set(ctx, map[string]interface{}{
	"name":    "Los Angeles",
	"state":   "CA",
	"country": "USA",
})
if err != nil {
	return err
}

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
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 ], options: SetOptions.merge())
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 }
     options:[FIRSetOptions merge]
     completion:^(NSError * _Nullable error) {
       // ...
     }];
  
Android
// 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());
Java
// The option to merge data is not yet available for Java. Instead, call the
// update method and pass the option to create the document if it's missing.

//asynchronously update doc, create the document if missing
Map<String, Object> update = new HashMap<>();
update.put("capital", true);

ApiFuture<WriteResult> writeResult =
    db
        .collection("cities")
        .document("BJ")
        .set(update, SetOptions.merge());
// ...
System.out.println("Update time : " + writeResult.get().getUpdateTime());
Python
# The option to merge data is not yet available for Python. Instead, call the
# update method and pass the option to create the document if it's missing.

city_ref = db.collection(u'cities').document(u'BJ')

city_ref.update({
    u'capital': True
}, firestore.CreateIfMissingOption(True))
Node.js
// The option to merge data is not yet available for Node.js. Instead, call the
// update method and pass the option to create the document if it's missing.

var cityRef = db.collection('cities').doc('BJ');

var setWithOptions = cityRef.set({
    capital: true
}, { merge: true });
Go
_, err := client.Collection("cities").Doc("BJ").Set(ctx, map[string]interface{}{
	"capital": true,
}, firestore.MergeAll)

if err != nil {
	return err
}

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.

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
var docData = {
    stringExample: "Hello world!",
    booleanExample: true,
    numberExample: 3.14159265,
    dateExample: 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(function() {
    console.log("Document successfully written!");
});
Swift
let docData: [String: Any] = [
    "stringExample": "Hello world!",
    "booleanExample": true,
    "numberExample": 3.14159265,
    "dateExample": NSDate(),
    "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": [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!");
      }
    }];
  
Android
Map<String, Object> docData = new HashMap<>();
docData.put("stringExample", "Hello world!");
docData.put("booleanExample", true);
docData.put("numberExample", 3.14159265);
docData.put("dateExample", 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);
            }
        });
Java
Map<String, Object> docData = new HashMap<>();
docData.put("stringExample", "Hello, World");
docData.put("booleanExample", false);
docData.put("numberExample", 3.14159265);
docData.put("nullExample", null);

ArrayList<Object> arrayExample = new ArrayList<>();
Collections.addAll(arrayExample, 5L, true, "hello");
docData.put("arrayExample", arrayExample);

Map<String, Object> objectExample = new HashMap<>();
objectExample.put("a", 5L);
objectExample.put("b", true);

docData.put("objectExample", objectExample);

ApiFuture<WriteResult> future = db.collection("data").document("one").set(docData);
System.out.println("Update time : " + future.get().getUpdateTime());
Python
data = {
    u'stringExample': u'Hello, World!',
    u'booleanExample': True,
    u'numberExample': 3.14159265,
    u'dateExample': datetime.datetime.now(),
    u'arrayExample': [5, True, u'hello'],
    u'nullExample': None,
    u'objectExample': {
        u'a': 5,
        u'b': True
    }
}

db.collection(u'data').document(u'one').set(data)
Node.js
var data = {
    stringExample: 'Hello, World!',
    booleanExample: true,
    numberExample: 3.14159265,
    dateExample: new Date('December 10, 1815'),
    arrayExample: [5, true, 'hello'],
    nullExample: null,
    objectExample: {
        a: 5,
        b: true
    }
};

var setDoc = db.collection('data').doc('one').set(data);
Go
doc := make(map[string]interface{})
doc["stringExample"] = "Hello world!"
doc["booleanExample"] = true
doc["numberExample"] = 3.14159265
doc["dateExample"] = time.Now()
doc["arrayExample"] = []interface{}{5, true, "hello"}
doc["nullExample"] = nil
doc["objectExample"] = map[string]interface{}{
	"a": 5,
	"b": true,
}

_, err := client.Collection("data").Doc("one").Set(ctx, doc)
if err != nil {
	return err
}

Custom objects

Using Java Map objects to represent your documents is often not very convenient, so Cloud Firestore also supports writing your own Java objects with custom classes. Cloud Firestore will internally convert the objects to supported data types.

Using custom classes, you could rewrite the initial example as follows:

Web
// Web uses JavaScript objects
Swift
// This isn't supported in Swift. Use a value type instead.
Objective-C
// This isn't supported in Objective-C.
  
Android
public class City {


    private String name;
    private String state;
    private String country;
    private boolean capital;
    private long population;

    public City() {}

    public City(String name, String state, String country, boolean capital, long population) {
        // ...
    }

    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;
    }

}
Java
public City() {
  // Must have a public no-argument constructor
}

// Initialize all fields of a city
public City(String name, String state, String country, Boolean capital, Long population) {
  this.name = name;
  this.state = state;
  this.country = country;
  this.capital = capital;
  this.population = population;
}
Python
class City(object):
    def __init__(self, name, state, country, capital=False, population=0):
        self.name = name
        self.state = state
        self.country = country
        self.capital = capital
        self.population = population

    @staticmethod
    def from_dict(source):
        # ...

    def to_dict(self):
        # ...

    def __repr__(self):
        return u'City(name={}, country={}, population={}, capital={})'.format(
            self.name, self.country, self.population, self.capital)
Node.js
// Node.js uses JavaScript objects
Go
// City represents a city.
type City struct {
	Name       string `firestore:"name,omitempty"`
	State      string `firestore:"state,omitempty"`
	Country    string `firestore:"country,omitempty"`
	Capital    bool   `firestore:"capital,omitempty"`
	Population int64  `firestore:"population,omitempty"`
}

Web
// Web uses JavaScript objects
Swift
// This isn't supported in Swift. Use a value type instead.
Objective-C
// This isn't supported in Objective-C.
  
Android
City city = new City("Los Angeles", "CA", "USA", false, 5000000L);
db.collection("cities").document("LA").set(city);
Java
City city = new City("Los Angeles", "CA", "USA", false, 3900000L);
ApiFuture<WriteResult> future = db.collection("cities").document("LA").set(city);
// block on response if required
System.out.println("Update time : " + future.get().getUpdateTime());
Python
city = City(name=u'Los Angeles', state=u'CA', country=u'USA')
db.collection(u'cities').document(u'LA').set(city.to_dict())
Node.js
// Node.js uses JavaScript objects
Go
city := City{
	Name:    "Los Angeles",
	Country: "USA",
}
_, err := client.Collection("cities").Doc("LA").Set(ctx, city)
if err != nil {
	return err
}

Add a document

When you use set() to create a document, you must specify an ID for the document to create. For example:

Web
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];
  
Android
db.collection("cities").document("new-city-id").set(data);
Java
db.collection("cities").document("new-city-id").set(data);
Python
db.collection(u'cities').document(u'new-city-id').set(data)
Node.js
db.collection('cities').doc('new-city-id').set(data);
Go
_, err := client.Collection("cities").Doc("new-city-id").Set(ctx, data)
if err != nil {
	return err
}

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 add():

Web
// Add a new document with a generated id.
db.collection("cities").add({
    name: "Tokyo",
    country: "Japan"
})
.then(function(docRef) {
    console.log("Document written with ID: ", docRef.id);
})
.catch(function(error) {
    console.error("Error adding document: ", error);
});
Swift
// 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
// 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);
      }
    }];
  
Android
// 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);
            }
        });
Java
// Add document data with auto-generated id.
Map<String, Object> data = new HashMap<>();
data.put("name", "Tokyo");
data.put("country", "Japan");
ApiFuture<DocumentReference> addedDocRef = db.collection("cities").add(data);
System.out.println("Added document with ID: " + addedDocRef.get().getId());
Python
city = City(name=u'Tokyo', state=None, country=u'Japan')
db.collection(u'cities').add(city.to_dict())
Node.js
// Add a new document with a generated id.
var addDoc = db.collection('cities').add({
    name: 'Tokyo',
    country: 'Japan'
}).then(ref => {
    console.log('Added document with ID: ', ref.id);
});
Go
_, _, err := client.Collection("cities").Add(ctx, map[string]interface{}{
	"name":    "Tokyo",
	"country": "Japan",
})
if err != nil {
	return err
}

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
// 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:@{ /* ... */ }];
  
Android
Map<String, Object> data = new HashMap<>();

DocumentReference newCityRef = db.collection("cities").document();

// Later...
newCityRef.set(data);
Java
// Add document data after generating an id.
DocumentReference addedDocRef = db.collection("cities").document();
System.out.println("Added document with ID: " + addedDocRef.getId());

// later...
ApiFuture<WriteResult> writeResult = addedDocRef.set(data);
Python
new_city_ref = db.collection(u'cities').document()

# later...
new_city_ref.set({
    # ...
})
Node.js
var newCityRef = db.collection('cities').doc();

// Later...
var setDoc = newCityRef.set({
    // ...
})
Go
ref := client.Collection("cities").NewDoc()

// later...
_, err := ref.Set(ctx, data)
if err != nil {
	return err
}

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 update() method:

Web
var washingtonRef = db.collection("cities").doc("DC");

// Set the "capital" field of the city 'DC'
return washingtonRef.update({
    capital: true
})
.then(function() {
    console.log("Document successfully updated!");
})
.catch(function(error) {
    // The document probably doesn't exist.
    console.error("Error updating document: ", error);
});
Swift
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
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");
  }
}];
  
Android
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);
            }
        });
Java
// Update an existing document
DocumentReference docRef = db.collection("cities").document("DC");

// (async) Update one field
ApiFuture<WriteResult> future = docRef.update("capital", true);

// ...
WriteResult result = future.get();
System.out.println("Write result: " + result);
Python
city_ref = db.collection(u'cities').document(u'DC')

# Set the capital field
city_ref.update({u'capital': True})
Node.js
var cityRef = db.collection('cities').doc('DC');

// Set the 'capital' field of the city
var updateSingle = cityRef.update({ capital: true });
Go
_, err := client.Collection("cities").Doc("DC").UpdateMap(ctx, map[string]interface{}{
	"capital": true,
})
if err != nil {
	return err
}

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
// 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(function() {
    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");
  }
}];
  
Android
// 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"
        );
Java
// Create an initial document to update
DocumentReference frankDocRef = db.collection("users").document("frank");
Map<String, Object> initialData = new HashMap<>();
initialData.put("name", "Frank");
initialData.put("age", 12);

Map<String, Object> favorites = new HashMap<>();
favorites.put("food", "Pizza");
favorites.put("color", "Blue");
favorites.put("subject", "Recess");
initialData.put("favorites", favorites);

ApiFuture<WriteResult> initialResult = frankDocRef.set(initialData);
// Confirm that data has been successfully saved by blocking on the operation
initialResult.get();

// Update age and favorite color
Map<String, Object> updates = new HashMap<>();
updates.put("age", 13);
updates.put("favorites.color", "Red");

// Async update document
ApiFuture<WriteResult> writeResult = frankDocRef.update(updates);
// ...
System.out.println("Update time : " + writeResult.get().getUpdateTime());
Python
# Create an initial document to update
frank_ref = db.collection(u'users').document(u'frank')
frank_ref.set({
    u'name': u'Frank',
    u'favorites': {
        u'food': u'Pizza',
        u'color': u'Blue',
        u'subject': u'Recess'
    },
    u'age': 12
})

# Update age and favorite color
frank_ref.update({
    u'age': 13,
    u'favorites.color': u'Red'
})
Node.js
var initialData = {
    name: 'Frank',
    age: 12,
    favorites: {
        food: 'Pizza',
        color: 'Blue',
        subject: 'recess'
    }
}

// ...
var updateNested = db.collection('users').doc('Frank').update({
    age: 13,
    favorites: {
        color: 'Red'
    }
});
Go
initialData := map[string]interface{}{
	"name": "Frank",
	"age":  12,
	"favorites": map[string]interface{}{
		"food":    "Pizza",
		"color":   "Blue",
		"subject": "recess",
	},
}

// ...

_, err = client.Collection("users").Doc("frank").UpdateMap(ctx, map[string]interface{}{
	"age":             13,
	"favorites.color": "Red",
})
if err != nil {
	return err
}

You can also add server timestamps to specific fields in your documents, to track when an update was received by the server:

Web
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");
  }
}];
  
Android
// 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>() {
    // ...
    // ...
Java
DocumentReference docRef = db.collection("objects").document("some-id");
// Update the timestamp field with the value from the server
ApiFuture<WriteResult> writeResult = docRef.update("timestamp", FieldValue.serverTimestamp());
System.out.println("Update time : " + writeResult.get());
Python
city_ref = db.collection(u'objects').document(u'some-id')
city_ref.update({
    u'timestamp': firestore.SERVER_TIMESTAMP
})
Node.js
// Get the `FieldValue` object
var FieldValue = require("firebase-admin").firestore.FieldValue;

// Create a document reference
var docRef = db.collection('objects').doc('some-id');

// Update the timestamp field with the value from the server
var updateTimestamp = docRef.update({
    timestamp: FieldValue.serverTimestamp()
});
Go
_, err := client.Collection("objects").Doc("some-id").UpdateMap(ctx, map[string]interface{}{
	"timestamp": firestore.ServerTimestamp,
})
if err != nil {
	return err
}

Send feedback about...

Need help? Visit our support page.