使用查詢游標對數據進行分頁

使用 Cloud Firestore 中的查詢遊標,您可以根據您在查詢中定義的參數將查詢傳回的資料拆分為多個批次。

查詢遊標定義查詢的起點和終點,讓您:

  • 傳回資料的子集。
  • 對查詢結果進行分頁。

但是,要定義查詢的特定範圍,您應該使用簡單查詢中所述的where()方法。

在查詢中新增簡單的遊標

使用startAt()startAfter()方法定義查詢的起點。 startAt()方法包含起始點,而startAfter()方法則排除起始點。

例如,如果您在查詢中使用startAt(A) ,它將傳回整個字母表。如果您改用startAfter(A) ,它將傳回BZ

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);
迅速
注意:此產品不適用於 watchOS 和 App Clip 目標。
// Get all cities with population over one million, ordered by population.
db.collection("cities")
  .order(by: "population")
  .start(at: [1000000])
Objective-C
注意:此產品不適用於 watchOS 和 App Clip 目標。
// 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]);
爪哇
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();
query := client.Collection("cities").OrderBy("population", firestore.Asc).StartAt(1000000)
PHP

PHP

有關安裝和建立 Cloud Firestore 用戶端的更多信息,請參閱Cloud Firestore 用戶端程式庫

$query = $citiesRef
    ->orderBy('population')
    ->startAt([1000000]);
統一
Query query = citiesRef.OrderBy("Population").StartAt(1000000);
C#
Query query = citiesRef.OrderBy("Population").StartAt(1000000);
紅寶石
query = cities_ref.order("population").start_at(1_000_000)

同樣,使用endAt()endBefore()方法定義查詢結果的結束點。

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);
迅速
注意:此產品不適用於 watchOS 和 App Clip 目標。
// Get all cities with population less than one million, ordered by population.
db.collection("cities")
  .order(by: "population")
  .end(at: [1000000])
Objective-C
注意:此產品不適用於 watchOS 和 App Clip 目標。
// 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]);
爪哇
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();
query := client.Collection("cities").OrderBy("population", firestore.Asc).EndAt(1000000)
PHP

PHP

有關安裝和建立 Cloud Firestore 用戶端的更多信息,請參閱Cloud Firestore 用戶端程式庫

$query = $citiesRef
    ->orderBy('population')
    ->endAt([1000000]);
統一
Query query = citiesRef.OrderBy("Population").EndAt(1000000);
C#
Query query = citiesRef.OrderBy("Population").EndAt(1000000);
紅寶石
query = cities_ref.order("population").end_at(1_000_000)

使用文件快照定義查詢遊標

您也可以將文件快照傳遞給遊標子句作為查詢遊標的起點或終點。文件快照中的值會用作查詢遊標中的值。

例如,拍攝城市和人口資料集中的「舊金山」文件的快照。然後,使用該文件快照作為總體查詢遊標的起點。您的查詢將傳回人口大於或等於舊金山的所有城市(如文件快照中所定義)。

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);

    // ...
});
迅速
注意:此產品不適用於 watchOS 和 App Clip 目標。
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)
  }
Objective-C
注意:此產品不適用於 watchOS 和 App Clip 目標。
[[[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"),
);
爪哇
// 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();
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

有關安裝和建立 Cloud Firestore 用戶端的更多信息,請參閱Cloud Firestore 用戶端程式庫

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

$query = $citiesRef
    ->orderBy('population')
    ->startAt($snapshot);
統一
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);
紅寶石
doc_ref = firestore.doc "#{collection_path}/SF"
snapshot = doc_ref.get
query = cities_ref.order("population").start_at(snapshot)

對查詢進行分頁

透過將查詢遊標與limit()方法結合起來對查詢進行分頁。例如,使用批次中的最後一個文件作為下一個批次的遊標的開頭。

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);
});
迅速
注意:此產品不適用於 watchOS 和 App Clip 目標。
// 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.
  // ...
}
Objective-C
注意:此產品不適用於 watchOS 和 App Clip 目標。
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"),
);
爪哇
// 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
// ...
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

有關安裝和建立 Cloud Firestore 用戶端的更多信息,請參閱Cloud Firestore 用戶端程式庫

$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();
統一
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();
紅寶石
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

基於多個欄位設定遊標

當使用基於欄位值(不是 DocumentSnapshot)的遊標時,您可以透過新增其他欄位來使遊標位置更加精確。如果您的資料集包含多個文檔,而這些文檔的遊標欄位都具有相同的值,從而使遊標的位置不明確,則此功能特別有用。您可以為遊標新增其他欄位值,以進一步指定起點或終點並減少歧義。

例如,在包含美國所有名為「Springfield」的城市的資料集中,查詢集將有多個起始點以「Springfield」開始:

城市
姓名狀態
史普林菲爾德麻薩諸塞州
史普林菲爾德密蘇裡州
史普林菲爾德威斯康辛州

要從特定的斯普林菲爾德開始,您可以在遊標子句中新增該州作為輔助條件。

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");
迅速
注意:此產品不適用於 watchOS 和 App Clip 目標。
// 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"])
Objective-C
注意:此產品不適用於 watchOS 和 App Clip 目標。
// 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"]);
爪哇
// 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();
// 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

有關安裝和建立 Cloud Firestore 用戶端的更多信息,請參閱Cloud Firestore 用戶端程式庫

// 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']);
統一
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");
紅寶石
# 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"])