Paginieren Sie Daten mit Abfragecursoren

Mit Abfragecursorn in Cloud Firestore können Sie die von einer Abfrage zurückgegebenen Daten entsprechend den von Ihnen in Ihrer Abfrage definierten Parametern in Stapel aufteilen.

Abfragecursor definieren die Start- und Endpunkte einer Abfrage und ermöglichen Ihnen Folgendes:

  • Gibt eine Teilmenge der Daten zurück.
  • Abfrageergebnisse paginieren.

Um jedoch einen bestimmten Bereich für eine Abfrage zu definieren, sollten Sie die in Einfache Abfragen beschriebene Methode where() verwenden.

Fügen Sie einer Abfrage einen einfachen Cursor hinzu

Verwenden Sie die Methoden startAt() oder startAfter() , um den Startpunkt für eine Abfrage zu definieren. Die Methode startAt() schließt den Startpunkt ein, während die Methode startAfter() ihn ausschließt.

Wenn Sie beispielsweise startAt(A) in einer Abfrage verwenden, wird das gesamte Alphabet zurückgegeben. Wenn Sie stattdessen startAfter(A) verwenden, wird BZ zurückgegeben.

Web modular API

import { query, orderBy, startAt } from "firebase/firestore";  

const q = query(citiesRef, orderBy("population"), startAt(1000000));

Web namespaced API

citiesRef.orderBy("population").startAt(1000000);
Schnell
Hinweis: Dieses Produkt ist nicht auf watchOS- und App Clip-Zielen verfügbar.
// Get all cities with population over one million, ordered by population.
db.collection("cities")
  .order(by: "population")
  .start(at: [1000000])
Ziel c
Hinweis: Dieses Produkt ist nicht auf watchOS- und App Clip-Zielen verfügbar.
// Get all cities with population over one million, ordered by population.
[[[db collectionWithPath:@"cities"]
    queryOrderedByField:@"population"]
    queryStartingAtValues:@[ @1000000 ]];

Kotlin+KTX

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

Java

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

Dart

db.collection("cities").orderBy("population").startAt([1000000]);
Java
Query query = cities.orderBy("population").startAt(4921000L);
Python
cities_ref = db.collection("cities")
query_start_at = cities_ref.order_by("population").start_at({"population": 1000000})

Python

cities_ref = db.collection("cities")
query_start_at = cities_ref.order_by("population").start_at({"population": 1000000})
C++
// Get all cities with a population >= 1,000,000, ordered by population,
db->Collection("cities")
    .OrderBy("population")
    .StartAt({FieldValue::Integer(1000000)});
Node.js
const startAtRes = await db.collection('cities')
  .orderBy('population')
  .startAt(1000000)
  .get();
Gehen
query := client.Collection("cities").OrderBy("population", firestore.Asc).StartAt(1000000)
PHP

PHP

Weitere Informationen zum Installieren und Erstellen eines Cloud Firestore-Clients finden Sie unter Cloud Firestore-Clientbibliotheken .

$query = $citiesRef
    ->orderBy('population')
    ->startAt([1000000]);
Einheit
Query query = citiesRef.OrderBy("Population").StartAt(1000000);
C#
Query query = citiesRef.OrderBy("Population").StartAt(1000000);
Rubin
query = cities_ref.order("population").start_at(1_000_000)

Verwenden Sie auf ähnliche Weise die Methoden endAt() oder endBefore() , um einen Endpunkt für Ihre Abfrageergebnisse zu definieren.

Web modular API

import { query, orderBy, endAt } from "firebase/firestore";  

const q = query(citiesRef, orderBy("population"), endAt(1000000));

Web namespaced API

citiesRef.orderBy("population").endAt(1000000);
Schnell
Hinweis: Dieses Produkt ist nicht auf watchOS- und App Clip-Zielen verfügbar.
// Get all cities with population less than one million, ordered by population.
db.collection("cities")
  .order(by: "population")
  .end(at: [1000000])
Ziel c
Hinweis: Dieses Produkt ist nicht auf watchOS- und App Clip-Zielen verfügbar.
// Get all cities with population less than one million, ordered by population.
[[[db collectionWithPath:@"cities"]
    queryOrderedByField:@"population"]
    queryEndingAtValues:@[ @1000000 ]];

Kotlin+KTX

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

Java

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

Dart

db.collection("cities").orderBy("population").endAt([1000000]);
Java
Query query = cities.orderBy("population").endAt(4921000L);
Python
cities_ref = db.collection("cities")
query_end_at = cities_ref.order_by("population").end_at({"population": 1000000})

Python

cities_ref = db.collection("cities")
query_end_at = cities_ref.order_by("population").end_at({"population": 1000000})
C++
// Get all cities with a population <= 1,000,000, ordered by population,
db->Collection("cities")
    .OrderBy("population")
    .EndAt({FieldValue::Integer(1000000)});
Node.js
const endAtRes = await db.collection('cities')
  .orderBy('population')
  .endAt(1000000)
  .get();
Gehen
query := client.Collection("cities").OrderBy("population", firestore.Asc).EndAt(1000000)
PHP

PHP

Weitere Informationen zum Installieren und Erstellen eines Cloud Firestore-Clients finden Sie unter Cloud Firestore-Clientbibliotheken .

$query = $citiesRef
    ->orderBy('population')
    ->endAt([1000000]);
Einheit
Query query = citiesRef.OrderBy("Population").EndAt(1000000);
C#
Query query = citiesRef.OrderBy("Population").EndAt(1000000);
Rubin
query = cities_ref.order("population").end_at(1_000_000)

Verwenden Sie einen Dokument-Snapshot, um den Abfragecursor zu definieren

Sie können der Cursor-Klausel auch einen Dokument-Snapshot als Start- oder Endpunkt des Abfragecursors übergeben. Die Werte im Dokument-Snapshot dienen als Werte im Abfragecursor.

Machen Sie beispielsweise einen Schnappschuss eines „San Francisco“-Dokuments in Ihrem Datensatz zu Städten und Bevölkerungsgruppen. Verwenden Sie dann diesen Dokument-Snapshot als Ausgangspunkt für Ihren Bevölkerungsabfragecursor. Ihre Abfrage gibt alle Städte zurück, deren Einwohnerzahl größer oder gleich der Einwohnerzahl von San Francisco ist, wie im Dokument-Snapshot definiert.

Web modular API

import { collection, doc, getDoc, query, orderBy, startAt } from "firebase/firestore";  
const citiesRef = collection(db, "cities");

const docSnap = await getDoc(doc(citiesRef, "SF"));

// Get all cities with a population bigger than San Francisco
const biggerThanSf = query(citiesRef, orderBy("population"), startAt(docSnap));
// ...

Web namespaced API

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

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

    // ...
});
Schnell
Hinweis: Dieses Produkt ist nicht auf watchOS- und App Clip-Zielen verfügbar.
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)
  }
Ziel c
Hinweis: Dieses Produkt ist nicht auf watchOS- und App Clip-Zielen verfügbar.
[[[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];
    }];

Kotlin+KTX

// 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)

        // ...
    }

Java

// 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);

                // ...
            }
        });

Dart

db.collection("cities").doc("SF").get().then(
  (documentSnapshot) {
    final biggerThanSf = db
        .collection("cities")
        .orderBy("population")
        .startAtDocument(documentSnapshot);
  },
  onError: (e) => print("Error: $e"),
);
Java
// 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);
Python
doc_ref = db.collection("cities").document("SF")

snapshot = doc_ref.get()
start_at_snapshot = (
    db.collection("cities").order_by("population").start_at(snapshot)
)

Python

doc_ref = db.collection("cities").document("SF")

snapshot = await doc_ref.get()
start_at_snapshot = (
    db.collection("cities").order_by("population").start_at(snapshot)
)
C++
db->Collection("cities").Document("SF").Get().OnCompletion(
    [db](const Future<DocumentSnapshot>& future) {
      if (future.error() == Error::kErrorOk) {
        const DocumentSnapshot& document_snapshot = *future.result();
        Query bigger_than_sf = db->Collection("cities")
                                   .OrderBy("population")
                                   .StartAt({document_snapshot});
        // ...
      }
    });
Node.js
const docRef = db.collection('cities').doc('SF');
const snapshot = await docRef.get();
const startAtSnapshot = db.collection('cities')
  .orderBy('population')
  .startAt(snapshot);

await startAtSnapshot.limit(10).get();
Gehen
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)
PHP

PHP

Weitere Informationen zum Installieren und Erstellen eines Cloud Firestore-Clients finden Sie unter Cloud Firestore-Clientbibliotheken .

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

$query = $citiesRef
    ->orderBy('population')
    ->startAt($snapshot);
Einheit
CollectionReference citiesRef = db.Collection("cities");
DocumentReference docRef = citiesRef.Document("SF");
docRef.GetSnapshotAsync().ContinueWith((snapshotTask) =>
{
    Query query = citiesRef.OrderBy("Population").StartAt(snapshotTask.Result);
});
C#
CollectionReference citiesRef = db.Collection("cities");
DocumentReference docRef = citiesRef.Document("SF");
DocumentSnapshot snapshot = await docRef.GetSnapshotAsync();
Query query = citiesRef.OrderBy("Population").StartAt(snapshot);
Rubin
doc_ref = firestore.doc "#{collection_path}/SF"
snapshot = doc_ref.get
query = cities_ref.order("population").start_at(snapshot)

Paginieren Sie eine Abfrage

Paginieren Sie Abfragen, indem Sie Abfragecursor mit der limit() Methode kombinieren. Verwenden Sie beispielsweise das letzte Dokument in einem Stapel als Anfang eines Cursors für den nächsten Stapel.

Web modular API

import { collection, query, orderBy, startAfter, limit, getDocs } from "firebase/firestore";  

// Query the first page of docs
const first = query(collection(db, "cities"), orderBy("population"), limit(25));
const documentSnapshots = await getDocs(first);

// Get the last visible document
const lastVisible = documentSnapshots.docs[documentSnapshots.docs.length-1];
console.log("last", lastVisible);

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

Web namespaced API

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

return first.get().then((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);
});
Schnell
Hinweis: Dieses Produkt ist nicht auf watchOS- und App Clip-Zielen verfügbar.
// 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.
  // ...
}
Ziel c
Hinweis: Dieses Produkt ist nicht auf watchOS- und App Clip-Zielen verfügbar.
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.
  // ...
}];

Kotlin+KTX

// 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
        // ...
    }

Java

// 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
            // ...
        }
    });

Dart

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

first.get().then(
  (documentSnapshots) {
    // Get the last visible document
    final lastVisible = documentSnapshots.docs[documentSnapshots.size - 1];

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

    // Use the query for pagination
    // ...
  },
  onError: (e) => print("Error completing: $e"),
);
Java
// 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();
Python
cities_ref = db.collection("cities")
first_query = cities_ref.order_by("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()["population"]

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

Python

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

# Get the last document from the results
docs = [d async for d in 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()["population"]

next_query = (
    cities_ref.order_by("population").start_after({"population": last_pop}).limit(3)
)
# Use the query for pagination
# ...
C++
// Construct query for first 25 cities, ordered by population
Query first = db->Collection("cities").OrderBy("population").Limit(25);

first.Get().OnCompletion([db](const Future<QuerySnapshot>& future) {
  if (future.error() != Error::kErrorOk) {
    // Handle error...
    return;
  }

  // Get the last visible document
  const QuerySnapshot& document_snapshots = *future.result();
  std::vector<DocumentSnapshot> documents = document_snapshots.documents();
  const DocumentSnapshot& last_visible = documents.back();

  // Construct a new query starting at this document,
  // get the next 25 cities.
  Query next = db->Collection("cities")
                   .OrderBy("population")
                   .StartAfter(last_visible)
                   .Limit(25);

  // Use the query for pagination
  // ...
});
Node.js
const first = db.collection('cities')
  .orderBy('population')
  .limit(3);

const snapshot = await first.get();

// Get the last document
const 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.
const next = db.collection('cities')
  .orderBy('population')
  .startAfter(last.data().population)
  .limit(3);

// Use the query for pagination
// ...
Gehen
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)

// ...
PHP

PHP

Weitere Informationen zum Installieren und Erstellen eines Cloud Firestore-Clients finden Sie unter Cloud Firestore-Clientbibliotheken .

$citiesRef = $db->collection('samples/php/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();
Einheit
CollectionReference citiesRef = db.Collection("cities");
Query firstQuery = citiesRef.OrderBy("Population").Limit(3);

// Get the last document from the results
firstQuery.GetSnapshotAsync().ContinueWith((querySnapshotTask) =>
{
    long lastPopulation = 0;
    foreach (DocumentSnapshot documentSnapshot in querySnapshotTask.Result.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);
    Task<QuerySnapshot> secondQuerySnapshot = secondQuery.GetSnapshotAsync();
C#
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();
Rubin
cities_ref  = firestore.col collection_path
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

Setzen Sie den Cursor basierend auf mehreren Feldern

Wenn Sie einen Cursor verwenden, der auf einem Feldwert basiert (kein DocumentSnapshot), können Sie die Cursorposition durch Hinzufügen zusätzlicher Felder präziser gestalten. Dies ist besonders nützlich, wenn Ihr Datensatz mehrere Dokumente enthält, die alle denselben Wert für Ihr Cursorfeld haben, wodurch die Position des Cursors mehrdeutig wird. Sie können Ihrem Cursor zusätzliche Feldwerte hinzufügen, um den Start- oder Endpunkt genauer festzulegen und Mehrdeutigkeiten zu reduzieren.

Beispielsweise gäbe es in einem Datensatz, der alle Städte mit dem Namen „Springfield“ in den Vereinigten Staaten enthält, mehrere Startpunkte für einen Abfragesatz, der bei „Springfield“ beginnt:

Städte
Name Zustand
Springfield Massachusetts
Springfield Missouri
Springfield Wisconsin

Um bei einem bestimmten Springfield zu beginnen, könnten Sie den Bundesstaat als sekundäre Bedingung in Ihre Cursor-Klausel einfügen.

Web modular API

// Will return all Springfields
import { collection, query, orderBy, startAt } from "firebase/firestore";  
const q1 = query(collection(db, "cities"),
   orderBy("name"),
   orderBy("state"),
   startAt("Springfield"));

// Will return "Springfield, Missouri" and "Springfield, Wisconsin"
const q2 = query(collection(db, "cities"),
   orderBy("name"),
   orderBy("state"),
   startAt("Springfield", "Missouri"));

Web namespaced API

// 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");
Schnell
Hinweis: Dieses Produkt ist nicht auf watchOS- und App Clip-Zielen verfügbar.
// 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"])
Ziel c
Hinweis: Dieses Produkt ist nicht auf watchOS- und App Clip-Zielen verfügbar.
// 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" ]];

Kotlin+KTX

// 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")

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");

Dart

// 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"]);
Java
// 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");
Python
start_at_name = (
    db.collection("cities").order_by("name").start_at({"name": "Springfield"})
)

start_at_name_and_state = (
    db.collection("cities")
    .order_by("name")
    .order_by("state")
    .start_at({"name": "Springfield", "state": "Missouri"})
)

Python

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

start_at_name_and_state = (
    db.collection("cities")
    .order_by("name")
    .order_by("state")
    .start_at({"name": "Springfield", "state": "Missouri"})
)
C++
// This is not yet supported.
Node.js
// Will return all Springfields
const startAtNameRes = await db.collection('cities')
  .orderBy('name')
  .orderBy('state')
  .startAt('Springfield')
  .get();

// Will return 'Springfield, Missouri' and 'Springfield, Wisconsin'
const startAtNameAndStateRes = await db.collection('cities')
  .orderBy('name')
  .orderBy('state')
  .startAt('Springfield', 'Missouri')
  .get();
Gehen
// 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")
PHP

PHP

Weitere Informationen zum Installieren und Erstellen eines Cloud Firestore-Clients finden Sie unter Cloud Firestore-Clientbibliotheken .

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

// Will return "Springfield, Missouri" and "Springfield, Wisconsin"
$query2 = $db
    ->collection('samples/php/cities')
    ->orderBy('name')
    ->orderBy('state')
    ->startAt(['Springfield', 'Missouri']);
Einheit
Query query1 = db.Collection("cities").OrderBy("Name").OrderBy("State").StartAt("Springfield");
Query query2 = db.Collection("cities").OrderBy("Name").OrderBy("State").StartAt("Springfield", "Missouri");
C#
Query query1 = db.Collection("cities").OrderBy("Name").OrderBy("State").StartAt("Springfield");
Query query2 = db.Collection("cities").OrderBy("Name").OrderBy("State").StartAt("Springfield", "Missouri");
Rubin
# Will return all Springfields
query1 = firestore.col(collection_path).order("name").order("state").start_at("Springfield")

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