Paginate data with query cursors

With query cursors in Cloud Firestore, you can split data returned by a query into batches according to the parameters you define in your query.

Query cursors define the start and end points for a query, allowing you to:

• Return a subset of the data.
• Paginate query results.

However, to define a specific range for a query, you should use the where() method described in Simple Queries.

Add a simple cursor to a query

Use the startAt() or startAfter() methods to define the start point for a query. The startAt() method includes the start point, while the startAfter() method excludes it.

For example, if you use startAt(A) in a query, it returns the entire alphabet. If you use startAfter(A) instead, it returns B-Z.

citiesRef.orderBy("population").startAt(1000000)
test.firestore.js

// Get all cities with population over one million, ordered by population.
db.collection("cities")
    .order(by: "population")
    .start(at: [1000000])
ViewController.swift

// Get all cities with population over one million, ordered by population.
[[[db collectionWithPath:@"cities"]
    queryOrderedByField:@"population"]
    queryStartingAtValues:@[ @1000000 ]];
ViewController.m
  

// Get all cities with a population >= 1,000,000, ordered by population,
db.collection("cities")
        .orderBy("population")
        .startAt(1000000);
DocSnippets.java

// Get all cities with a population >= 1,000,000, ordered by population,
db.collection("cities")
        .orderBy("population")
        .startAt(1000000)
DocSnippets.kt

Query query = cities.orderBy("population").startAt(4921000L);
QueryDataSnippets.java

cities_ref = db.collection(u'cities')
query_start_at = cities_ref.order_by(u'population').start_at({
    u'population': 1000000
})
snippets.py

let startAt = db.collection('cities')
  .orderBy('population')
  .startAt(1000000);
index.js

query := client.Collection("cities").OrderBy("population", firestore.Asc).StartAt(1000000)
query.go

$query = $citiesRef
    ->orderBy('population')
    ->startAt([1000000]);
start_at_field_query_cursor.php

Query query = citiesRef.OrderBy("Population").StartAt(1000000);
Program.cs

query = cities_ref.order("population").start_at(1_000_000)
paginate_data.rb

Similarly, use the endAt() or endBefore() methods to define an end point for your query results.

citiesRef.orderBy("population").endAt(1000000)
test.firestore.js

// Get all cities with population less than one million, ordered by population.
db.collection("cities")
    .order(by: "population")
    .end(at: [1000000])
ViewController.swift

// Get all cities with population less than one million, ordered by population.
[[[db collectionWithPath:@"cities"]
    queryOrderedByField:@"population"]
    queryEndingAtValues:@[ @1000000 ]];
ViewController.m
  

// Get all cities with a population <= 1,000,000, ordered by population,
db.collection("cities")
        .orderBy("population")
        .endAt(1000000);
DocSnippets.java

// Get all cities with a population <= 1,000,000, ordered by population,
db.collection("cities")
        .orderBy("population")
        .endAt(1000000)
DocSnippets.kt

Query query = cities.orderBy("population").endAt(4921000L);
QueryDataSnippets.java

cities_ref = db.collection(u'cities')
query_end_at = cities_ref.order_by(u'population').end_at({
    u'population': 1000000
})
snippets.py

let endAt = db.collection('cities')
  .orderBy('population')
  .endAt(1000000);
index.js

query := client.Collection("cities").OrderBy("population", firestore.Asc).EndAt(1000000)
query.go

$query = $citiesRef
    ->orderBy('population')
    ->endAt([1000000]);
end_at_field_query_cursor.php

Query query = citiesRef.OrderBy("Population").EndAt(1000000);
Program.cs

query = cities_ref.order("population").end_at(1_000_000)
paginate_data.rb

Use a document snapshot to define the query cursor

You can also pass a document snapshot to the cursor clause as the start or end point of the query cursor. The values in the document snapshot serve as the values in the query cursor.

For example, take a snapshot of a "San Francisco" document in your data set of cities and populations. Then, use that document snapshot as the start point for your population query cursor. Your query will return all the cities with a population larger than or equal to San Francisco's, as defined in the document snapshot.

var citiesRef = db.collection("cities");

return citiesRef.doc("SF").get().then(function(doc) {
    // Get all cities with a population bigger than San Francisco
    var biggerThanSf = citiesRef
        .orderBy("population")
        .startAt(doc);

    // ...
});
test.firestore.js

db.collection("cities")
    .document("SF")
    .addSnapshotListener { (document, error) in
        guard let document = document else {
            print("Error retreving cities: \(error.debugDescription)")
            return
        }

        // Get all cities with a population greater than or equal to San Francisco.
        let sfSizeOrBigger = db.collection("cities")
            .order(by: "population")
            .start(atDocument: document)
}
ViewController.swift

[[[db collectionWithPath:@"cities"] documentWithPath:@"SF"]
    addSnapshotListener:^(FIRDocumentSnapshot *snapshot, NSError *error) {
      if (snapshot == nil) {
        NSLog(@"Error retreiving cities: %@", error);
        return;
      }
      // Get all cities with a population greater than or equal to San Francisco.
      FIRQuery *sfSizeOrBigger = [[[db collectionWithPath:@"cities"]
          queryOrderedByField:@"population"]
          queryStartingAtDocument:snapshot];
    }];
ViewController.m
  

// Get the data for "San Francisco"
db.collection("cities").document("SF")
        .get()
        .addOnSuccessListener(new OnSuccessListener<DocumentSnapshot>() {
            @Override
            public void onSuccess(DocumentSnapshot documentSnapshot) {
                // Get all cities with a population bigger than San Francisco.
                Query biggerThanSf = db.collection("cities")
                        .orderBy("population")
                        .startAt(documentSnapshot);

                // ...
            }
        });
DocSnippets.java

// Get the data for "San Francisco"
db.collection("cities").document("SF")
        .get()
        .addOnSuccessListener { documentSnapshot ->
            // Get all cities with a population bigger than San Francisco.
            val biggerThanSf = db.collection("cities")
                    .orderBy("population")
                    .startAt(documentSnapshot)

            // ...
        }
DocSnippets.kt

// Fetch the snapshot with an API call, waiting for a maximum of 30 seconds for a result.
ApiFuture<DocumentSnapshot> future = db.collection("cities").document("SF").get();
DocumentSnapshot snapshot = future.get(30, TimeUnit.SECONDS);

// Construct the query
Query query = db.collection("cities")
    .orderBy("population")
    .startAt(snapshot);
QueryDataSnippets.java

doc_ref = db.collection(u'cities').document(u'SF')

snapshot = doc_ref.get()
start_at_snapshot = db.collection(
    u'cities').order_by(u'population').start_at(snapshot)
snippets.py

let docRef = db.collection('cities').doc('SF');
return docRef.get().then(snapshot => {
  let startAtSnapshot = db.collection('cities')
    .orderBy('population')
    .startAt(snapshot);

  return startAtSnapshot.limit(10).get();
});
index.js

cities := client.Collection("cities")
dsnap, err := cities.Doc("SF").Get(ctx)
if err != nil {
	fmt.Println(err)
}
query := cities.OrderBy("population", firestore.Asc).StartAt(dsnap.Data()["population"]).Documents(ctx)
query.go

$citiesRef = $db->collection('cities');
$docRef = $citiesRef->document('SF');
$snapshot = $docRef->snapshot();

$query = $citiesRef
    ->orderBy('population')
    ->startAt($snapshot);
start_at_snapshot_query_cursor.php

CollectionReference citiesRef = db.Collection("cities");
DocumentReference docRef = citiesRef.Document("SF");
DocumentSnapshot snapshot = await docRef.GetSnapshotAsync();
Query query = citiesRef.OrderBy("Population").StartAt(snapshot);
Program.cs

// Snippet not available

Paginate a query

Paginate queries by combining query cursors with the limit() method. For example, use the last document in a batch as the start of a cursor for the next batch.

var first = db.collection("cities")
        .orderBy("population")
        .limit(25);

return first.get().then(function (documentSnapshots) {
  // Get the last visible document
  var lastVisible = documentSnapshots.docs[documentSnapshots.docs.length-1];
  console.log("last", lastVisible);

  // Construct a new query starting at this document,
  // get the next 25 cities.
  var next = db.collection("cities")
          .orderBy("population")
          .startAfter(lastVisible)
          .limit(25);
});
test.firestore.js

// Construct query for first 25 cities, ordered by population
let first = db.collection("cities")
    .order(by: "population")
    .limit(to: 25)

first.addSnapshotListener { (snapshot, error) in
    guard let snapshot = snapshot else {
        print("Error retreving cities: \(error.debugDescription)")
        return
    }

    guard let lastSnapshot = snapshot.documents.last else {
        // The collection is empty.
        return
    }

    // Construct a new query starting after this document,
    // retrieving the next 25 cities.
    let next = db.collection("cities")
        .order(by: "population")
        .start(afterDocument: lastSnapshot)

    // Use the query for pagination.
    // ...
}
ViewController.swift

FIRQuery *first = [[[db collectionWithPath:@"cities"]
    queryOrderedByField:@"population"]
    queryLimitedTo:25];
[first addSnapshotListener:^(FIRQuerySnapshot *snapshot, NSError *error) {
  if (snapshot == nil) {
    NSLog(@"Error retreiving cities: %@", error);
    return;
  }
  if (snapshot.documents.count == 0) { return; }
  FIRDocumentSnapshot *lastSnapshot = snapshot.documents.lastObject;

  // Construct a new query starting after this document,
  // retreiving the next 25 cities.
  FIRQuery *next = [[[db collectionWithPath:@"cities"]
      queryOrderedByField:@"population"]
      queryStartingAfterDocument:lastSnapshot];
  // Use the query for pagination.
  // ...
}];
ViewController.m
  

// Construct query for first 25 cities, ordered by population
Query first = db.collection("cities")
        .orderBy("population")
        .limit(25);

first.get()
    .addOnSuccessListener(new OnSuccessListener<QuerySnapshot>() {
        @Override
        public void onSuccess(QuerySnapshot documentSnapshots) {
            // ...

            // Get the last visible document
            DocumentSnapshot lastVisible = documentSnapshots.getDocuments()
                    .get(documentSnapshots.size() -1);

            // Construct a new query starting at this document,
            // get the next 25 cities.
            Query next = db.collection("cities")
                    .orderBy("population")
                    .startAfter(lastVisible)
                    .limit(25);

            // Use the query for pagination
            // ...
        }
    });
DocSnippets.java

// Construct query for first 25 cities, ordered by population
val first = db.collection("cities")
        .orderBy("population")
        .limit(25)

first.get()
        .addOnSuccessListener { documentSnapshots ->
            // ...

            // Get the last visible document
            val lastVisible = documentSnapshots.documents[documentSnapshots.size() - 1]

            // Construct a new query starting at this document,
            // get the next 25 cities.
            val next = db.collection("cities")
                    .orderBy("population")
                    .startAfter(lastVisible)
                    .limit(25)

            // Use the query for pagination
            // ...
        }
DocSnippets.kt

// Construct query for first 25 cities, ordered by population.
CollectionReference cities = db.collection("cities");
Query firstPage = cities
    .orderBy("population")
    .limit(25);

// Wait for the results of the API call, waiting for a maximum of 30 seconds for a result.
ApiFuture<QuerySnapshot> future = firstPage.get();
List<QueryDocumentSnapshot> docs = future.get(30, TimeUnit.SECONDS).getDocuments();

// Construct query for the next 25 cities.
QueryDocumentSnapshot lastDoc = docs.get(docs.size() - 1);
Query secondPage = cities
    .orderBy("population")
    .startAfter(lastDoc)
    .limit(25);

future = secondPage.get();
docs = future.get(30, TimeUnit.SECONDS).getDocuments();
QueryDataSnippets.java

cities_ref = db.collection(u'cities')
first_query = cities_ref.order_by(u'population').limit(3)

# Get the last document from the results
docs = first_query.stream()
last_doc = list(docs)[-1]

# Construct a new query starting at this document
# Note: this will not have the desired effect if
# multiple cities have the exact same population value
last_pop = last_doc.to_dict()[u'population']

next_query = (
    cities_ref
    .order_by(u'population')
    .start_after({
        u'population': last_pop
    })
    .limit(3)
)
# Use the query for pagination
# ...
snippets.py

let first = db.collection('cities')
  .orderBy('population')
  .limit(3);

let paginate = first.get()
  .then((snapshot) => {
    // ...

    // Get the last document
    let last = snapshot.docs[snapshot.docs.length - 1];

    // Construct a new query starting at this document.
    // Note: this will not have the desired effect if multiple
    // cities have the exact same population value.
    let next = db.collection('cities')
      .orderBy('population')
      .startAfter(last.data().population)
      .limit(3);

    // Use the query for pagination
    // ...
  });
index.js

cities := client.Collection("cities")

// Get the first 25 cities, ordered by population.
firstPage := cities.OrderBy("population", firestore.Asc).Limit(25).Documents(ctx)
docs, err := firstPage.GetAll()
if err != nil {
	return err
}

// Get the last document.
lastDoc := docs[len(docs)-1]

// Construct a new query to get the next 25 cities.
secondPage := cities.OrderBy("population", firestore.Asc).
	StartAfter(lastDoc.Data()["population"]).
	Limit(25)

// ...
query.go

$citiesRef = $db->collection('cities');
$firstQuery = $citiesRef->orderBy('population')->limit(3);

# Get the last document from the results
$documents = $firstQuery->documents();
$lastPopulation = 0;
foreach ($documents as $document) {
    $lastPopulation = $document['population'];
}

# Construct a new query starting at this document
# Note: this will not have the desired effect if multiple cities have the exact same population value
$nextQuery = $citiesRef->orderBy('population')->startAfter([$lastPopulation]);
$snapshot = $nextQuery->documents();
paginated_query_cursor.php

CollectionReference citiesRef = db.Collection("cities");
Query firstQuery = citiesRef.OrderBy("Population").Limit(3);

// Get the last document from the results
QuerySnapshot querySnapshot = await firstQuery.GetSnapshotAsync();
long lastPopulation = 0;
foreach (DocumentSnapshot documentSnapshot in querySnapshot.Documents)
{
    lastPopulation = documentSnapshot.GetValue<long>("Population");
}

// Construct a new query starting at this document.
// Note: this will not have the desired effect if multiple cities have the exact same population value
Query secondQuery = citiesRef.OrderBy("Population").StartAfter(lastPopulation);
QuerySnapshot secondQuerySnapshot = await secondQuery.GetSnapshotAsync();
Program.cs

cities_ref  = firestore.col "cities"
first_query = cities_ref.order("population").limit(3)

# Get the last document from the results.
last_population = 0
first_query.get do |city|
  last_population = city.data[:population]
end

# Construct a new query starting at this document.
# Note: this will not have the desired effect if multiple cities have the exact same population value.
second_query = cities_ref.order("population").start_after(last_population)
second_query.get do |city|
  puts "Document #{city.document_id} returned by paginated query cursor."
end
paginate_data.rb

Set cursor based on multiple fields

When using a cursor based on a field value (not a DocumentSnapshot), you can make the cursor position more precise by adding additional fields. This is particularly useful if your data set includes multiple documents that all have the same value for your cursor field, making the cursor's position ambiguous. You can add additional field values to your cursor to further specify the start or end point and reduce ambiguity.

For example, in a data set containing all the cities named "Springfield" in the United States, there would be multiple start points for a query set to start at "Springfield":

To start at a specific Springfield, you could add the state as a secondary condition in your cursor clause.

// Will return all Springfields
db.collection("cities")
   .orderBy("name")
   .orderBy("state")
   .startAt("Springfield")

// Will return "Springfield, Missouri" and "Springfield, Wisconsin"
db.collection("cities")
   .orderBy("name")
   .orderBy("state")
   .startAt("Springfield", "Missouri")
test.firestore.js

// Will return all Springfields
db.collection("cities")
    .order(by: "name")
    .order(by: "state")
    .start(at: ["Springfield"])

// Will return "Springfield, Missouri" and "Springfield, Wisconsin"
db.collection("cities")
    .order(by: "name")
    .order(by: "state")
    .start(at: ["Springfield", "Missouri"])
ViewController.swift

// Will return all Springfields
[[[[db collectionWithPath:@"cities"]
    queryOrderedByField:@"name"]
    queryOrderedByField:@"state"]
    queryStartingAtValues:@[ @"Springfield" ]];
// Will return "Springfield, Missouri" and "Springfield, Wisconsin"
[[[[db collectionWithPath:@"cities"]
   queryOrderedByField:@"name"]
   queryOrderedByField:@"state"]
   queryStartingAtValues:@[ @"Springfield", @"Missouri" ]];
ViewController.m
  

// Will return all Springfields
db.collection("cities")
        .orderBy("name")
        .orderBy("state")
        .startAt("Springfield");

// Will return "Springfield, Missouri" and "Springfield, Wisconsin"
db.collection("cities")
        .orderBy("name")
        .orderBy("state")
        .startAt("Springfield", "Missouri");
DocSnippets.java

// Will return all Springfields
db.collection("cities")
        .orderBy("name")
        .orderBy("state")
        .startAt("Springfield")

// Will return "Springfield, Missouri" and "Springfield, Wisconsin"
db.collection("cities")
        .orderBy("name")
        .orderBy("state")
        .startAt("Springfield", "Missouri")
DocSnippets.kt

// Will return all Springfields
Query query1 = db.collection("cities")
    .orderBy("name")
    .orderBy("state")
    .startAt("Springfield");

// Will return "Springfield, Missouri" and "Springfield, Wisconsin"
Query query2 = db.collection("cities")
    .orderBy("name")
    .orderBy("state")
    .startAt("Springfield", "Missouri");
QueryDataSnippets.java

start_at_name = (
    db.collection(u'cities')
    .order_by(u'name')
    .order_by(u'state')
    .start_at({
        u'name': u'Springfield'
    })
)

start_at_name_and_state = (
    db.collection(u'cities')
    .order_by(u'name')
    .order_by(u'state')
    .start_at({
        u'name': u'Springfield',
        u'state': u'Missouri'
    })
)
snippets.py

// Will return all Springfields
let startAtName = db.collection('cities')
  .orderBy('name')
  .orderBy('state')
  .startAt('Springfield');
index.js
// Will return 'Springfield, Missouri' and 'Springfield, Wisconsin'
let startAtNameAndState = db.collection('cities')
  .orderBy('name')
  .orderBy('state')
  .startAt('Springfield', 'Missouri');
index.js

// Will return all Springfields.
client.Collection("cities").
	OrderBy("name", firestore.Asc).
	OrderBy("state", firestore.Asc).
	StartAt("Springfield")

// Will return Springfields where state comes after Wisconsin.
client.Collection("cities").
	OrderBy("name", firestore.Asc).
	OrderBy("state", firestore.Asc).
	StartAt("Springfield", "Wisconsin")
query.go

// Will return all Springfields
$query1 = $db
    ->collection('cities')
    ->orderBy('name')
    ->orderBy('state')
    ->startAt(['Springfield']);

// Will return "Springfield, Missouri" and "Springfield, Wisconsin"
$query2 = $db
    ->collection('cities')
    ->orderBy('name')
    ->orderBy('state')
    ->startAt(['Springfield', 'Missouri']);
multiple_cursor_conditions.php

Query query1 = db.Collection("cities").OrderBy("Name").OrderBy("State").StartAt("Springfield");
Query query2 = db.Collection("cities").OrderBy("Name").OrderBy("State").StartAt("Springfield", "Missouri");
Program.cs

# Will return all Springfields
query1 = firestore.col("cities").order("name").order("state").start_at("Springfield")

# Will return "Springfield, Missouri" and "Springfield, Wisconsin"
query2 = firestore.col("cities").order("name").order("state").start_at(["Springfield", "Missouri"])
paginate_data.rb