Paginacja danych za pomocą kursorów zapytań

Dzięki kursorom zapytań w Cloud Firestore możesz podzielić dane zwrócone przez zapytanie na partie zgodnie z parametrami zdefiniowanymi w zapytaniu.

Kursory zapytań definiują punkt początkowy i końcowy zapytania, umożliwiając:

  • Zwróć podzbiór danych.
  • Podział wyników zapytania na strony.

Aby jednak zdefiniować konkretny zakres zapytania, należy użyć metody where() opisanej w sekcji Proste zapytania .

Dodaj prosty kursor do zapytania

Użyj startAt() lub startAfter() , aby zdefiniować punkt początkowy zapytania. Metoda startAt() zawiera punkt początkowy, natomiast metoda startAfter() wyklucza go.

Na przykład, jeśli użyjesz startAt(A) w zapytaniu, zwróci cały alfabet. Jeśli zamiast tego użyjesz startAfter(A) , zwraca on BZ .

Web version 9

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

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

Web version 8

citiesRef.orderBy("population").startAt(1000000);
test.firestore.js
Szybki
Uwaga: ten produkt nie jest dostępny w systemach docelowych watchOS i App Clip.
// Get all cities with population over one million, ordered by population.
db.collection("cities")
    .order(by: "population")
    .start(at: [1000000])
ViewController.swift
Cel C
Uwaga: ten produkt nie jest dostępny w systemach docelowych watchOS i App Clip.
// Get all cities with population over one million, ordered by population.
[[[db collectionWithPath:@"cities"]
    queryOrderedByField:@"population"]
    queryStartingAtValues:@[ @1000000 ]];
ViewController.m

Java

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

Kotlin+KTX

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

Dart

db.collection("cities").orderBy("population").startAt([1000000]);
firestore.dart
Jawa
Query query = cities.orderBy("population").startAt(4921000L);
QueryDataSnippets.java
Pyton
cities_ref = db.collection(u'cities')
query_start_at = cities_ref.order_by(u'population').start_at({
    u'population': 1000000
})
snippets.py

Python

cities_ref = db.collection("cities")
query_start_at = cities_ref.order_by("population").start_at({"population": 1000000})
snippets.py
C++
// Get all cities with a population >= 1,000,000, ordered by population,
db->Collection("cities")
    .OrderBy("population")
    .StartAt({FieldValue::Integer(1000000)});
snippets.cpp
Node.js
const startAtRes = await db.collection('cities')
  .orderBy('population')
  .startAt(1000000)
  .get();
index.js
Udać się
query := client.Collection("cities").OrderBy("population", firestore.Asc).StartAt(1000000)
query.go
PHP
$query = $citiesRef
    ->orderBy('population')
    ->startAt([1000000]);
query_cursor_start_at_field_value_single.php
Jedność
Query query = citiesRef.OrderBy("Population").StartAt(1000000);
C#
Query query = citiesRef.OrderBy("Population").StartAt(1000000);
Program.cs
Rubin
query = cities_ref.order("population").start_at(1_000_000)
paginate_data.rb

Podobnie użyj endAt() lub endBefore() , aby zdefiniować punkt końcowy wyników zapytania.

Web version 9

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

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

Web version 8

citiesRef.orderBy("population").endAt(1000000);
test.firestore.js
Szybki
Uwaga: ten produkt nie jest dostępny w systemach docelowych watchOS i App Clip.
// Get all cities with population less than one million, ordered by population.
db.collection("cities")
    .order(by: "population")
    .end(at: [1000000])
ViewController.swift
Cel C
Uwaga: ten produkt nie jest dostępny w systemach docelowych watchOS i App Clip.
// Get all cities with population less than one million, ordered by population.
[[[db collectionWithPath:@"cities"]
    queryOrderedByField:@"population"]
    queryEndingAtValues:@[ @1000000 ]];
ViewController.m

Java

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

Kotlin+KTX

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

Dart

db.collection("cities").orderBy("population").endAt([1000000]);
firestore.dart
Jawa
Query query = cities.orderBy("population").endAt(4921000L);
QueryDataSnippets.java
Pyton
cities_ref = db.collection(u'cities')
query_end_at = cities_ref.order_by(u'population').end_at({
    u'population': 1000000
})
snippets.py

Python

cities_ref = db.collection("cities")
query_end_at = cities_ref.order_by("population").end_at({"population": 1000000})
snippets.py
C++
// Get all cities with a population <= 1,000,000, ordered by population,
db->Collection("cities")
    .OrderBy("population")
    .EndAt({FieldValue::Integer(1000000)});
snippets.cpp
Node.js
const endAtRes = await db.collection('cities')
  .orderBy('population')
  .endAt(1000000)
  .get();
index.js
Udać się
query := client.Collection("cities").OrderBy("population", firestore.Asc).EndAt(1000000)
query.go
PHP
$query = $citiesRef
    ->orderBy('population')
    ->endAt([1000000]);
query_cursor_end_at_field_value_single.php
Jedność
Query query = citiesRef.OrderBy("Population").EndAt(1000000);
C#
Query query = citiesRef.OrderBy("Population").EndAt(1000000);
Program.cs
Rubin
query = cities_ref.order("population").end_at(1_000_000)
paginate_data.rb

Użyj migawki dokumentu, aby zdefiniować kursor zapytania

Migawkę dokumentu można również przekazać do klauzuli kursora jako punktu początkowego lub końcowego kursora zapytania. Wartości w migawce dokumentu służą jako wartości w kursorze zapytania.

Na przykład zrób migawkę dokumentu „San Francisco” w zestawie danych miast i populacji. Następnie użyj tej migawki dokumentu jako punktu początkowego dla kursora zapytania populacyjnego. Twoje zapytanie zwróci wszystkie miasta o liczbie mieszkańców większej lub równej liczbie mieszkańców San Francisco, zgodnie z definicją w migawce dokumentu.

Web version 9

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));
// ...
start_doc.js

Web version 8

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);

    // ...
});
test.firestore.js
Szybki
Uwaga: ten produkt nie jest dostępny w systemach docelowych watchOS i App Clip.
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
Cel C
Uwaga: ten produkt nie jest dostępny w systemach docelowych watchOS i App Clip.
[[[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

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);

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

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)

            // ...
        }
DocSnippets.kt

Dart

db.collection("cities").doc("SF").get().then(
  (documentSnapshot) {
    final biggerThanSf = db
        .collection("cities")
        .orderBy("population")
        .startAt([documentSnapshot]);
  },
  onError: (e) => print("Error: $e"),
);
firestore.dart
Jawa
// 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
Pyton
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

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)
)
snippets.py
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});
        // ...
      }
    });
snippets.cpp
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();
index.js
Udać się
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
PHP
$citiesRef = $db->collection('samples/php/cities');
$docRef = $citiesRef->document('SF');
$snapshot = $docRef->snapshot();

$query = $citiesRef
    ->orderBy('population')
    ->startAt($snapshot);
query_cursor_start_at_document.php
Jedność
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);
Program.cs
Rubin
doc_ref = firestore.doc "#{collection_path}/SF"
snapshot = doc_ref.get
query = cities_ref.order("population").start_at(snapshot)
paginate_data.rb

Paginuj zapytanie

Podział zapytań na strony, łącząc kursory zapytań z metodą limit() . Na przykład użyj ostatniego dokumentu w partii jako początku kursora dla następnej partii.

Web version 9

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));
paginate.js

Web version 8

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);
});
test.firestore.js
Szybki
Uwaga: ten produkt nie jest dostępny w systemach docelowych watchOS i App Clip.
// 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
Cel C
Uwaga: ten produkt nie jest dostępny w systemach docelowych watchOS i App Clip.
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

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

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
            // ...
        }
DocSnippets.kt

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")
        .startAfter([lastVisible]).limit(25);

    // Use the query for pagination
    // ...
  },
  onError: (e) => print("Error completing: $e"),
);
firestore.dart
Jawa
// 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
Pyton
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

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
# ...
snippets.py
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
  // ...
});
snippets.cpp
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
// ...
index.js
Udać się
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
PHP
$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();
query_cursor_pagination.php
Jedność
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();
Program.cs
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
paginate_data.rb

Ustaw kursor na podstawie wielu pól

Korzystając z kursora opartego na wartości pola (nie na DocumentSnapshot), można dokładniej określić położenie kursora, dodając dodatkowe pola. Jest to szczególnie przydatne, jeśli zestaw danych zawiera wiele dokumentów, które mają tę samą wartość pola kursora, co sprawia, że ​​pozycja kursora jest niejednoznaczna. Możesz dodać dodatkowe wartości pól do kursora, aby dokładniej określić punkt początkowy lub końcowy i zmniejszyć niejednoznaczność.

Na przykład w zestawie danych zawierającym wszystkie miasta o nazwie „Springfield” w Stanach Zjednoczonych byłoby wiele punktów początkowych dla zestawu zapytań rozpoczynającego się od „Springfield”:

Miasta
Nazwać Stan
Springfield Massachusetts
Springfield Missouri
Springfield Wisconsin

Aby zacząć od konkretnego Springfield, możesz dodać stan jako warunek drugorzędny w klauzuli kursora.

Web version 9

// 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"));
start_multiple_orderby.js

Web version 8

// 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
Szybki
Uwaga: ten produkt nie jest dostępny w systemach docelowych watchOS i App Clip.
// 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
Cel C
Uwaga: ten produkt nie jest dostępny w systemach docelowych watchOS i App Clip.
// 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

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.java

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")
DocSnippets.kt

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"]);
firestore.dart
Jawa
// 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
Pyton
start_at_name = (
    db.collection(u'cities')
    .order_by(u'name')
    .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

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"})
)
snippets.py
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();
index.js
Udać się
// 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
PHP
// 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']);
query_cursor_start_at_field_value_multi.php
Jedność
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");
Program.cs
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"])
paginate_data.rb