Mit Sammlungen den Überblick behalten Sie können Inhalte basierend auf Ihren Einstellungen speichern und kategorisieren.

Daten abfragen und filtern

Firestore bietet leistungsstarke Abfragefunktionen, mit denen sich Dokumente aus einer Sammlung oder Sammlungsgruppe abrufen lassen. Diese Abfragen können Sie auch mit den Methoden get() und addSnapshotListener() verwenden, wie unter Daten abrufen und Echtzeitdaten abrufen erläutert.

Beispieldaten

Schreiben zuerst einige Daten über Städte, damit wir verschiedene Arten betrachten können, wie sie gelesen werden können:

Webversion 9

import { collection, doc, setDoc } from "firebase/firestore";

const citiesRef = collection(db, "cities");

await setDoc(doc(citiesRef, "SF"), {
    name: "San Francisco", state: "CA", country: "USA",
    capital: false, population: 860000,
    regions: ["west_coast", "norcal"] });
await setDoc(doc(citiesRef, "LA"), {
    name: "Los Angeles", state: "CA", country: "USA",
    capital: false, population: 3900000,
    regions: ["west_coast", "socal"] });
await setDoc(doc(citiesRef, "DC"), {
    name: "Washington, D.C.", state: null, country: "USA",
    capital: true, population: 680000,
    regions: ["east_coast"] });
await setDoc(doc(citiesRef, "TOK"), {
    name: "Tokyo", state: null, country: "Japan",
    capital: true, population: 9000000,
    regions: ["kanto", "honshu"] });
await setDoc(doc(citiesRef, "BJ"), {
    name: "Beijing", state: null, country: "China",
    capital: true, population: 21500000,
    regions: ["jingjinji", "hebei"] });
example_data.js

Webversion 8

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

citiesRef.doc("SF").set({
    name: "San Francisco", state: "CA", country: "USA",
    capital: false, population: 860000,
    regions: ["west_coast", "norcal"] });
citiesRef.doc("LA").set({
    name: "Los Angeles", state: "CA", country: "USA",
    capital: false, population: 3900000,
    regions: ["west_coast", "socal"] });
citiesRef.doc("DC").set({
    name: "Washington, D.C.", state: null, country: "USA",
    capital: true, population: 680000,
    regions: ["east_coast"] });
citiesRef.doc("TOK").set({
    name: "Tokyo", state: null, country: "Japan",
    capital: true, population: 9000000,
    regions: ["kanto", "honshu"] });
citiesRef.doc("BJ").set({
    name: "Beijing", state: null, country: "China",
    capital: true, population: 21500000,
    regions: ["jingjinji", "hebei"] });
test.firestore.js
Swift
Hinweis: Dieses Produkt nicht ist auf WatchOS- und App Clip-Zielen verfügbar. 
let citiesRef = db.collection("cities")

citiesRef.document("SF").setData([
    "name": "San Francisco",
    "state": "CA",
    "country": "USA",
    "capital": false,
    "population": 860000,
    "regions": ["west_coast", "norcal"]
    ])
citiesRef.document("LA").setData([
    "name": "Los Angeles",
    "state": "CA",
    "country": "USA",
    "capital": false,
    "population": 3900000,
    "regions": ["west_coast", "socal"]
    ])
citiesRef.document("DC").setData([
    "name": "Washington D.C.",
    "country": "USA",
    "capital": true,
    "population": 680000,
    "regions": ["east_coast"]
    ])
citiesRef.document("TOK").setData([
    "name": "Tokyo",
    "country": "Japan",
    "capital": true,
    "population": 9000000,
    "regions": ["kanto", "honshu"]
    ])
citiesRef.document("BJ").setData([
    "name": "Beijing",
    "country": "China",
    "capital": true,
    "population": 21500000,
    "regions": ["jingjinji", "hebei"]
    ])
ViewController.swift
Objective-C
Hinweis: Dieses Produkt nicht ist auf WatchOS- und App Clip-Zielen verfügbar. 
FIRCollectionReference *citiesRef = [self.db collectionWithPath:@"cities"];
[[citiesRef documentWithPath:@"SF"] setData:@{
  @"name": @"San Francisco",
  @"state": @"CA",
  @"country": @"USA",
  @"capital": @(NO),
  @"population": @860000,
  @"regions": @[@"west_coast", @"norcal"]
}];
[[citiesRef documentWithPath:@"LA"] setData:@{
  @"name": @"Los Angeles",
  @"state": @"CA",
  @"country": @"USA",
  @"capital": @(NO),
  @"population": @3900000,
  @"regions": @[@"west_coast", @"socal"]
}];
[[citiesRef documentWithPath:@"DC"] setData:@{
  @"name": @"Washington D.C.",
  @"country": @"USA",
  @"capital": @(YES),
  @"population": @680000,
  @"regions": @[@"east_coast"]
}];
[[citiesRef documentWithPath:@"TOK"] setData:@{
  @"name": @"Tokyo",
  @"country": @"Japan",
  @"capital": @(YES),
  @"population": @9000000,
  @"regions": @[@"kanto", @"honshu"]
}];
[[citiesRef documentWithPath:@"BJ"] setData:@{
  @"name": @"Beijing",
  @"country": @"China",
  @"capital": @(YES),
  @"population": @21500000,
  @"regions": @[@"jingjinji", @"hebei"]
}];
ViewController.m
Kotlin+KTX
Android
val cities = db.collection("cities")

val data1 = hashMapOf(
        "name" to "San Francisco",
        "state" to "CA",
        "country" to "USA",
        "capital" to false,
        "population" to 860000,
        "regions" to listOf("west_coast", "norcal")
)
cities.document("SF").set(data1)

val data2 = hashMapOf(
        "name" to "Los Angeles",
        "state" to "CA",
        "country" to "USA",
        "capital" to false,
        "population" to 3900000,
        "regions" to listOf("west_coast", "socal")
)
cities.document("LA").set(data2)

val data3 = hashMapOf(
        "name" to "Washington D.C.",
        "state" to null,
        "country" to "USA",
        "capital" to true,
        "population" to 680000,
        "regions" to listOf("east_coast")
)
cities.document("DC").set(data3)

val data4 = hashMapOf(
        "name" to "Tokyo",
        "state" to null,
        "country" to "Japan",
        "capital" to true,
        "population" to 9000000,
        "regions" to listOf("kanto", "honshu")
)
cities.document("TOK").set(data4)

val data5 = hashMapOf(
        "name" to "Beijing",
        "state" to null,
        "country" to "China",
        "capital" to true,
        "population" to 21500000,
        "regions" to listOf("jingjinji", "hebei")
)
cities.document("BJ").set(data5)
DocSnippets.kt
Java
Android
CollectionReference cities = db.collection("cities");

Map<String, Object> data1 = new HashMap<>();
data1.put("name", "San Francisco");
data1.put("state", "CA");
data1.put("country", "USA");
data1.put("capital", false);
data1.put("population", 860000);
data1.put("regions", Arrays.asList("west_coast", "norcal"));
cities.document("SF").set(data1);

Map<String, Object> data2 = new HashMap<>();
data2.put("name", "Los Angeles");
data2.put("state", "CA");
data2.put("country", "USA");
data2.put("capital", false);
data2.put("population", 3900000);
data2.put("regions", Arrays.asList("west_coast", "socal"));
cities.document("LA").set(data2);

Map<String, Object> data3 = new HashMap<>();
data3.put("name", "Washington D.C.");
data3.put("state", null);
data3.put("country", "USA");
data3.put("capital", true);
data3.put("population", 680000);
data3.put("regions", Arrays.asList("east_coast"));
cities.document("DC").set(data3);

Map<String, Object> data4 = new HashMap<>();
data4.put("name", "Tokyo");
data4.put("state", null);
data4.put("country", "Japan");
data4.put("capital", true);
data4.put("population", 9000000);
data4.put("regions", Arrays.asList("kanto", "honshu"));
cities.document("TOK").set(data4);

Map<String, Object> data5 = new HashMap<>();
data5.put("name", "Beijing");
data5.put("state", null);
data5.put("country", "China");
data5.put("capital", true);
data5.put("population", 21500000);
data5.put("regions", Arrays.asList("jingjinji", "hebei"));
cities.document("BJ").set(data5);
DocSnippets.java

Dart

final cities = db.collection("cities");
final data1 = <String, dynamic>{
  "name": "San Francisco",
  "state": "CA",
  "country": "USA",
  "capital": false,
  "population": 860000,
  "regions": ["west_coast", "norcal"]
};
cities.doc("SF").set(data1);

final data2 = <String, dynamic>{
  "name": "Los Angeles",
  "state": "CA",
  "country": "USA",
  "capital": false,
  "population": 3900000,
  "regions": ["west_coast", "socal"],
};
cities.doc("LA").set(data2);

final data3 = <String, dynamic>{
  "name": "Washington D.C.",
  "state": null,
  "country": "USA",
  "capital": true,
  "population": 680000,
  "regions": ["east_coast"]
};
cities.doc("DC").set(data3);

final data4 = <String, dynamic>{
  "name": "Tokyo",
  "state": null,
  "country": "Japan",
  "capital": true,
  "population": 9000000,
  "regions": ["kanto", "honshu"]
};
cities.doc("TOK").set(data4);

final data5 = <String, dynamic>{
  "name": "Beijing",
  "state": null,
  "country": "China",
  "capital": true,
  "population": 21500000,
  "regions": ["jingjinji", "hebei"],
};
cities.doc("BJ").set(data5);
firestore.dart
Java
CollectionReference cities = db.collection("cities");
List<ApiFuture<WriteResult>> futures = new ArrayList<>();
futures.add(
    cities
        .document("SF")
        .set(
            new City(
                "San Francisco",
                "CA",
                "USA",
                false,
                860000L,
                Arrays.asList("west_coast", "norcal"))));
futures.add(
    cities
        .document("LA")
        .set(
            new City(
                "Los Angeles",
                "CA",
                "USA",
                false,
                3900000L,
                Arrays.asList("west_coast", "socal"))));
futures.add(
    cities
        .document("DC")
        .set(
            new City(
                "Washington D.C.", null, "USA", true, 680000L, Arrays.asList("east_coast"))));
futures.add(
    cities
        .document("TOK")
        .set(
            new City(
                "Tokyo", null, "Japan", true, 9000000L, Arrays.asList("kanto", "honshu"))));
futures.add(
    cities
        .document("BJ")
        .set(
            new City(
                "Beijing",
                null,
                "China",
                true,
                21500000L,
                Arrays.asList("jingjinji", "hebei"))));
// (optional) block on documents successfully added
ApiFutures.allAsList(futures).get();
QueryDataSnippets.java
Python
class City(object):
    def __init__(self, name, state, country, capital=False, population=0,
                 regions=[]):
        self.name = name
        self.state = state
        self.country = country
        self.capital = capital
        self.population = population
        self.regions = regions

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

    def to_dict(self):
        # ...

    def __repr__(self):
        return (
            f'City(\
                name={self.name}, \
                country={self.country}, \
                population={self.population}, \
                capital={self.capital}, \
                regions={self.regions}\
            )'
        )
cities_ref = db.collection(u'cities')
cities_ref.document(u'BJ').set(
    City(u'Beijing', None, u'China', True, 21500000, [u'hebei']).to_dict())
cities_ref.document(u'SF').set(
    City(u'San Francisco', u'CA', u'USA', False, 860000,
         [u'west_coast', u'norcal']).to_dict())
cities_ref.document(u'LA').set(
    City(u'Los Angeles', u'CA', u'USA', False, 3900000,
         [u'west_coast', u'socal']).to_dict())
cities_ref.document(u'DC').set(
    City(u'Washington D.C.', None, u'USA', True, 680000,
         [u'east_coast']).to_dict())
cities_ref.document(u'TOK').set(
    City(u'Tokyo', None, u'Japan', True, 9000000,
         [u'kanto', u'honshu']).to_dict())
snippets.py
Python
(Async)
class City(object):
    def __init__(self, name, state, country, capital=False, population=0, regions=[]):
        self.name = name
        self.state = state
        self.country = country
        self.capital = capital
        self.population = population
        self.regions = regions

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

    def to_dict(self):
        # ...

    def __repr__(self):
        return f"City(\
                name={self.name}, \
                country={self.country}, \
                population={self.population}, \
                capital={self.capital}, \
                regions={self.regions}\
            )"

cities_ref = db.collection("cities")
await cities_ref.document("BJ").set(
    City("Beijing", None, "China", True, 21500000, ["hebei"]).to_dict()
)
await cities_ref.document("SF").set(
    City(
        "San Francisco", "CA", "USA", False, 860000, ["west_coast", "norcal"]
    ).to_dict()
)
await cities_ref.document("LA").set(
    City(
        "Los Angeles", "CA", "USA", False, 3900000, ["west_coast", "socal"]
    ).to_dict()
)
await cities_ref.document("DC").set(
    City("Washington D.C.", None, "USA", True, 680000, ["east_coast"]).to_dict()
)
await cities_ref.document("TOK").set(
    City("Tokyo", None, "Japan", True, 9000000, ["kanto", "honshu"]).to_dict()
)
snippets.py
C++
CollectionReference cities = db->Collection("cities");

cities.Document("SF").Set({
    {"name", FieldValue::String("San Francisco")},
    {"state", FieldValue::String("CA")},
    {"country", FieldValue::String("USA")},
    {"capital", FieldValue::Boolean(false)},
    {"population", FieldValue::Integer(860000)},
    {"regions", FieldValue::Array({FieldValue::String("west_coast"),
                                   FieldValue::String("norcal")})},
});

cities.Document("LA").Set({
    {"name", FieldValue::String("Los Angeles")},
    {"state", FieldValue::String("CA")},
    {"country", FieldValue::String("USA")},
    {"capital", FieldValue::Boolean(false)},
    {"population", FieldValue::Integer(3900000)},
    {"regions", FieldValue::Array({FieldValue::String("west_coast"),
                                   FieldValue::String("socal")})},
});

cities.Document("DC").Set({
    {"name", FieldValue::String("Washington D.C.")},
    {"state", FieldValue::Null()},
    {"country", FieldValue::String("USA")},
    {"capital", FieldValue::Boolean(true)},
    {"population", FieldValue::Integer(680000)},
    {"regions",
     FieldValue::Array({FieldValue::String("east_coast")})},
});

cities.Document("TOK").Set({
    {"name", FieldValue::String("Tokyo")},
    {"state", FieldValue::Null()},
    {"country", FieldValue::String("Japan")},
    {"capital", FieldValue::Boolean(true)},
    {"population", FieldValue::Integer(9000000)},
    {"regions", FieldValue::Array({FieldValue::String("kanto"),
                                   FieldValue::String("honshu")})},
});

cities.Document("BJ").Set({
    {"name", FieldValue::String("Beijing")},
    {"state", FieldValue::Null()},
    {"country", FieldValue::String("China")},
    {"capital", FieldValue::Boolean(true)},
    {"population", FieldValue::Integer(21500000)},
    {"regions", FieldValue::Array({FieldValue::String("jingjinji"),
                                   FieldValue::String("hebei")})},
});
snippets.cpp
Node.js
const citiesRef = db.collection('cities');

await citiesRef.doc('SF').set({
  name: 'San Francisco', state: 'CA', country: 'USA',
  capital: false, population: 860000,
  regions: ['west_coast', 'norcal']
});
await citiesRef.doc('LA').set({
  name: 'Los Angeles', state: 'CA', country: 'USA',
  capital: false, population: 3900000,
  regions: ['west_coast', 'socal']
});
await citiesRef.doc('DC').set({
  name: 'Washington, D.C.', state: null, country: 'USA',
  capital: true, population: 680000,
  regions: ['east_coast']
});
await citiesRef.doc('TOK').set({
  name: 'Tokyo', state: null, country: 'Japan',
  capital: true, population: 9000000,
  regions: ['kanto', 'honshu']
});
await citiesRef.doc('BJ').set({
  name: 'Beijing', state: null, country: 'China',
  capital: true, population: 21500000,
  regions: ['jingjinji', 'hebei']
});
index.js
Einfach loslegen (Go)
cities := []struct {
	id string
	c  City
}{
	{
		id: "SF",
		c: City{Name: "San Francisco", State: "CA", Country: "USA",
			Capital: false, Population: 860000,
			Regions: []string{"west_coast", "norcal"}},
	},
	{
		id: "LA",
		c: City{Name: "Los Angeles", State: "CA", Country: "USA",
			Capital: false, Population: 3900000,
			Regions: []string{"west_coast", "socal"}},
	},
	{
		id: "DC",
		c: City{Name: "Washington D.C.", Country: "USA",
			Capital: true, Population: 680000,
			Regions: []string{"east_coast"}},
	},
	{
		id: "TOK",
		c: City{Name: "Tokyo", Country: "Japan",
			Capital: true, Population: 9000000,
			Regions: []string{"kanto", "honshu"}},
	},
	{
		id: "BJ",
		c: City{Name: "Beijing", Country: "China",
			Capital: true, Population: 21500000,
			Regions: []string{"jingjinji", "hebei"}},
	},
}
for _, c := range cities {
	if _, err := client.Collection("cities").Doc(c.id).Set(ctx, c.c); err != nil {
		return err
	}
}
query.go
PHP
$citiesRef = $db->collection('samples/php/cities');
$citiesRef->document('SF')->set([
    'name' => 'San Francisco',
    'state' => 'CA',
    'country' => 'USA',
    'capital' => false,
    'population' => 860000,
    'regions' => ['west_coast', 'norcal']
]);
$citiesRef->document('LA')->set([
    'name' => 'Los Angeles',
    'state' => 'CA',
    'country' => 'USA',
    'capital' => false,
    'population' => 3900000,
    'regions' => ['west_coast', 'socal']
]);
$citiesRef->document('DC')->set([
    'name' => 'Washington D.C.',
    'state' => null,
    'country' => 'USA',
    'capital' => true,
    'population' => 680000,
    'regions' => ['east_coast']
]);
$citiesRef->document('TOK')->set([
    'name' => 'Tokyo',
    'state' => null,
    'country' => 'Japan',
    'capital' => true,
    'population' => 9000000,
    'regions' => ['kanto', 'honshu']
]);
$citiesRef->document('BJ')->set([
    'name' => 'Beijing',
    'state' => null,
    'country' => 'China',
    'capital' => true,
    'population' => 21500000,
    'regions' => ['jingjinji', 'hebei']
]);
printf('Added example cities data to the cities collection.' . PHP_EOL);
query_filter_dataset.php
Unity
CollectionReference citiesRef = db.Collection("cities");
citiesRef.Document("SF").SetAsync(new Dictionary<string, object>(){
    { "Name", "San Francisco" },
    { "State", "CA" },
    { "Country", "USA" },
    { "Capital", false },
    { "Population", 860000 },
    { "Regions", new ArrayList{"west_coast", "norcal"} }
});
citiesRef.Document("LA").SetAsync(new Dictionary<string, object>(){
    { "Name", "Los Angeles" },
    { "State", "CA" },
    { "Country", "USA" },
    { "Capital", false },
    { "Population", 3900000 },
    { "Regions", new ArrayList{"west_coast", "socal"} }
});
citiesRef.Document("DC").SetAsync(new Dictionary<string, object>(){
    { "Name", "Washington D.C." },
    { "State", null },
    { "Country", "USA" },
    { "Capital", true },
    { "Population", 680000 },
    { "Regions", new ArrayList{"east_coast"} }
});
citiesRef.Document("TOK").SetAsync(new Dictionary<string, object>(){
    { "Name", "Tokyo" },
    { "State", null },
    { "Country", "Japan" },
    { "Capital", true },
    { "Population", 9000000 },
    { "Regions", new ArrayList{"kanto", "honshu"} }
});
citiesRef.Document("BJ").SetAsync(new Dictionary<string, object>(){
    { "Name", "Beijing" },
    { "State", null },
    { "Country", "China" },
    { "Capital", true },
    { "Population", 21500000 },
    { "Regions", new ArrayList{"jingjinji", "hebei"} }
});
C#
CollectionReference citiesRef = db.Collection("cities");
await citiesRef.Document("SF").SetAsync(new Dictionary<string, object>(){
    { "Name", "San Francisco" },
    { "State", "CA" },
    { "Country", "USA" },
    { "Capital", false },
    { "Population", 860000 },
    { "Regions", new ArrayList{"west_coast", "norcal"} }
});
await citiesRef.Document("LA").SetAsync(new Dictionary<string, object>(){
    { "Name", "Los Angeles" },
    { "State", "CA" },
    { "Country", "USA" },
    { "Capital", false },
    { "Population", 3900000 },
    { "Regions", new ArrayList{"west_coast", "socal"} }
});
await citiesRef.Document("DC").SetAsync(new Dictionary<string, object>(){
    { "Name", "Washington D.C." },
    { "State", null },
    { "Country", "USA" },
    { "Capital", true },
    { "Population", 680000 },
    { "Regions", new ArrayList{"east_coast"} }
});
await citiesRef.Document("TOK").SetAsync(new Dictionary<string, object>(){
    { "Name", "Tokyo" },
    { "State", null },
    { "Country", "Japan" },
    { "Capital", true },
    { "Population", 9000000 },
    { "Regions", new ArrayList{"kanto", "honshu"} }
});
await citiesRef.Document("BJ").SetAsync(new Dictionary<string, object>(){
    { "Name", "Beijing" },
    { "State", null },
    { "Country", "China" },
    { "Capital", true },
    { "Population", 21500000 },
    { "Regions", new ArrayList{"jingjinji", "hebei"} }
});
Console.WriteLine("Added example cities data to the cities collection.");
Program.cs
Ruby
cities_ref = firestore.col collection_path
cities_ref.doc("SF").set(
  {
    name:       "San Francisco",
    state:      "CA",
    country:    "USA",
    capital:    false,
    population: 860_000,
    regions:    ["west_coast", "norcal"]
  }
)
cities_ref.doc("LA").set(
  {
    name:       "Los Angeles",
    state:      "CA",
    country:    "USA",
    capital:    false,
    population: 3_900_000,
    regions:    ["west_coast", "socal"]
  }
)
cities_ref.doc("DC").set(
  {
    name:       "Washington D.C.",
    state:      nil,
    country:    "USA",
    capital:    true,
    population: 680_000,
    regions:    ["east_coast"]
  }
)
cities_ref.doc("TOK").set(
  {
    name:       "Tokyo",
    state:      nil,
    country:    "Japan",
    capital:    true,
    population: 9_000_000,
    regions:    ["kanto", "honshu"]
  }
)
cities_ref.doc("BJ").set(
  {
    name:       "Beijing",
    state:      nil,
    country:    "China",
    capital:    true,
    population: 21_500_000,
    regions:    ["jingjinji", "hebei"]
  }
)
query_data.rb

Einfache Abfragen

Die folgende Abfrage gibt alle Städte mit dem Bundesstaat CA zurück:

Webversion 9

// Create a reference to the cities collection
import { collection, query, where } from "firebase/firestore";
const citiesRef = collection(db, "cities");

// Create a query against the collection.
const q = query(citiesRef, where("state", "==", "CA"));
simple_queries.js

Webversion 8

// Create a reference to the cities collection
var citiesRef = db.collection("cities");

// Create a query against the collection.
var query = citiesRef.where("state", "==", "CA");
test.firestore.js
Swift
Hinweis: Dieses Produkt nicht ist auf WatchOS- und App Clip-Zielen verfügbar. 
// Create a reference to the cities collection
let citiesRef = db.collection("cities")

// Create a query against the collection.
let query = citiesRef.whereField("state", isEqualTo: "CA")
ViewController.swift
Objective-C
Hinweis: Dieses Produkt nicht ist auf WatchOS- und App Clip-Zielen verfügbar. 
// Create a reference to the cities collection
FIRCollectionReference *citiesRef = [self.db collectionWithPath:@"cities"];
// Create a query against the collection.
FIRQuery *query = [citiesRef queryWhereField:@"state" isEqualTo:@"CA"];
ViewController.m
Kotlin+KTX
Android
// Create a reference to the cities collection
val citiesRef = db.collection("cities")

// Create a query against the collection.
val query = citiesRef.whereEqualTo("state", "CA")
DocSnippets.kt
Java
Android
// Create a reference to the cities collection
CollectionReference citiesRef = db.collection("cities");

// Create a query against the collection.
Query query = citiesRef.whereEqualTo("state", "CA");
DocSnippets.java

Dart

// Create a reference to the cities collection
final citiesRef = db.collection("cities");

// Create a query against the collection.
final query = citiesRef.where("state", isEqualTo: "CA");
firestore.dart
Java
// Create a reference to the cities collection
CollectionReference cities = db.collection("cities");
// Create a query against the collection.
Query query = cities.whereEqualTo("state", "CA");
// retrieve  query results asynchronously using query.get()
ApiFuture<QuerySnapshot> querySnapshot = query.get();

for (DocumentSnapshot document : querySnapshot.get().getDocuments()) {
  System.out.println(document.getId());
}
QueryDataSnippets.java
Python
# Create a reference to the cities collection
cities_ref = db.collection(u'cities')

# Create a query against the collection
query_ref = cities_ref.where(u'state', u'==', u'CA')
snippets.py
Python
(Async)
# Create a reference to the cities collection
cities_ref = db.collection("cities")

# Create a query against the collection
query_ref = cities_ref.where("state", "==", "CA")
snippets.py
C++
CollectionReference cities_ref = db->Collection("cities");
// Create a query against the collection.
Query query_ca =
    cities_ref.WhereEqualTo("state", FieldValue::String("CA"));
snippets.cpp
Node.js
// Create a reference to the cities collection
const citiesRef = db.collection('cities');

// Create a query against the collection
const queryRef = citiesRef.where('state', '==', 'CA');
index.js
Einfach loslegen (Go)
query := client.Collection("cities").Where("state", "==", "CA")
query.go
PHP
$citiesRef = $db->collection('samples/php/cities');
$query = $citiesRef->where('state', '=', 'CA');
$snapshot = $query->documents();
foreach ($snapshot as $document) {
    printf('Document %s returned by query state=CA' . PHP_EOL, $document->id());
}
query_filter_eq_string.php
Unity
CollectionReference citiesRef = db.Collection("cities");
Query query = citiesRef.WhereEqualTo("State", "CA");
query.GetSnapshotAsync().ContinueWithOnMainThread((querySnapshotTask) =>
{
    foreach (DocumentSnapshot documentSnapshot in querySnapshotTask.Result.Documents)
    {
        Debug.Log(String.Format("Document {0} returned by query State=CA", documentSnapshot.Id));
    }
});
C#
CollectionReference citiesRef = db.Collection("cities");
Query query = citiesRef.WhereEqualTo("State", "CA");
QuerySnapshot querySnapshot = await query.GetSnapshotAsync();
foreach (DocumentSnapshot documentSnapshot in querySnapshot.Documents)
{
    Console.WriteLine("Document {0} returned by query State=CA", documentSnapshot.Id);
}
Program.cs
Ruby
cities_ref = firestore.col collection_path

query = cities_ref.where "state", "=", "CA"

query.get do |city|
  puts "Document #{city.document_id} returned by query state=CA."
end
query_data.rb

Die folgende Abfrage gibt alle Hauptstädte zurück:

Webversion 9

import { collection, query, where } from "firebase/firestore";
const citiesRef = collection(db, "cities");

const q = query(citiesRef, where("capital", "==", true));
simple_queries_again.js

Webversion 8

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

var query = citiesRef.where("capital", "==", true);
test.firestore.js
Swift
Hinweis: Dieses Produkt nicht ist auf WatchOS- und App Clip-Zielen verfügbar. 
let capitalCities = db.collection("cities").whereField("capital", isEqualTo: true)
ViewController.swift
Objective-C
Hinweis: Dieses Produkt nicht ist auf WatchOS- und App Clip-Zielen verfügbar. 
FIRQuery *capitalCities =
    [[self.db collectionWithPath:@"cities"] queryWhereField:@"capital" isEqualTo:@YES];
ViewController.m
Kotlin+KTX
Android
val capitalCities = db.collection("cities").whereEqualTo("capital", true)
DocSnippets.kt
Java
Android
Query capitalCities = db.collection("cities").whereEqualTo("capital", true);
DocSnippets.java

Dart

final capitalcities =
    db.collection("cities").where("capital", isEqualTo: true);
firestore.dart
Java
// Create a reference to the cities collection
CollectionReference cities = db.collection("cities");
// Create a query against the collection.
Query query = cities.whereEqualTo("capital", true);
// retrieve  query results asynchronously using query.get()
ApiFuture<QuerySnapshot> querySnapshot = query.get();

for (DocumentSnapshot document : querySnapshot.get().getDocuments()) {
  System.out.println(document.getId());
}
QueryDataSnippets.java
Python
cities_ref = db.collection(u'cities')

query = cities_ref.where(u'capital', u'==', True)
snippets.py
Python
(Async)
cities_ref = db.collection("cities")

query = cities_ref.where("capital", "==", True)
snippets.py
C++
Query capital_cities = db->Collection("cities").WhereEqualTo(
    "capital", FieldValue::Boolean(true));
snippets.cpp
Node.js
// Create a reference to the cities collection
const citiesRef = db.collection('cities');

// Create a query against the collection
const allCapitalsRes = await citiesRef.where('capital', '==', true).get();
index.js
Einfach loslegen (Go)
query := client.Collection("cities").Where("capital", "==", true)
query.go
PHP
$citiesRef = $db->collection('samples/php/cities');
$query = $citiesRef->where('capital', '=', true);
$snapshot = $query->documents();
foreach ($snapshot as $document) {
    printf('Document %s returned by query capital=true' . PHP_EOL, $document->id());
}
query_filter_eq_boolean.php
Unity
CollectionReference citiesRef = db.Collection("cities");
Query query = citiesRef.WhereEqualTo("Capital", true);
query.GetSnapshotAsync().ContinueWithOnMainThread((querySnapshotTask) =>
{
    foreach (DocumentSnapshot documentSnapshot in querySnapshotTask.Result.Documents)
    {
        Debug.Log(String.Format("Document {0} returned by query Capital=true", documentSnapshot.Id));
    }
});
C#
CollectionReference citiesRef = db.Collection("cities");
Query query = citiesRef.WhereEqualTo("Capital", true);
QuerySnapshot querySnapshot = await query.GetSnapshotAsync();
foreach (DocumentSnapshot documentSnapshot in querySnapshot.Documents)
{
    Console.WriteLine("Document {0} returned by query Capital=true", documentSnapshot.Id);
}
Program.cs
Ruby
cities_ref = firestore.col collection_path

query = cities_ref.where "capital", "=", true

query.get do |city|
  puts "Document #{city.document_id} returned by query capital=true."
end
query_data.rb

Abfrage ausführen

Nach dem Erstellen eines Abfrageobjekts rufen Sie die Ergebnisse mithilfe der Funktion get() ab:

Webversion 9

import { collection, query, where, getDocs } from "firebase/firestore";

const q = query(collection(db, "cities"), where("capital", "==", true));

const querySnapshot = await getDocs(q);
querySnapshot.forEach((doc) => {
  // doc.data() is never undefined for query doc snapshots
  console.log(doc.id, " => ", doc.data());
});
get_multiple.js

Webversion 8

db.collection("cities").where("capital", "==", true)
    .get()
    .then((querySnapshot) => {
        querySnapshot.forEach((doc) => {
            // doc.data() is never undefined for query doc snapshots
            console.log(doc.id, " => ", doc.data());
        });
    })
    .catch((error) => {
        console.log("Error getting documents: ", error);
    });
test.firestore.js
Swift
Hinweis: Dieses Produkt nicht ist auf WatchOS- und App Clip-Zielen verfügbar. 
db.collection("cities").whereField("capital", isEqualTo: true)
    .getDocuments() { (querySnapshot, err) in
        if let err = err {
            print("Error getting documents: \(err)")
        } else {
            for document in querySnapshot!.documents {
                print("\(document.documentID) => \(document.data())")
            }
        }
}
ViewController.swift
Objective-C
Hinweis: Dieses Produkt nicht ist auf WatchOS- und App Clip-Zielen verfügbar. 
[[[self.db collectionWithPath:@"cities"] queryWhereField:@"capital" isEqualTo:@(YES)]
    getDocumentsWithCompletion:^(FIRQuerySnapshot *snapshot, NSError *error) {
      if (error != nil) {
        NSLog(@"Error getting documents: %@", error);
      } else {
        for (FIRDocumentSnapshot *document in snapshot.documents) {
          NSLog(@"%@ => %@", document.documentID, document.data);
        }
      }
    }];
ViewController.m
Kotlin+KTX
Android
db.collection("cities")
        .whereEqualTo("capital", true)
        .get()
        .addOnSuccessListener { documents ->
            for (document in documents) {
                Log.d(TAG, "${document.id} => ${document.data}")
            }
        }
        .addOnFailureListener { exception ->
            Log.w(TAG, "Error getting documents: ", exception)
        }
DocSnippets.kt
Java
Android
db.collection("cities")
        .whereEqualTo("capital", true)
        .get()
        .addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {
            @Override
            public void onComplete(@NonNull Task<QuerySnapshot> task) {
                if (task.isSuccessful()) {
                    for (QueryDocumentSnapshot document : task.getResult()) {
                        Log.d(TAG, document.getId() + " => " + document.getData());
                    }
                } else {
                    Log.d(TAG, "Error getting documents: ", task.getException());
                }
            }
        });
DocSnippets.java

Dart

db.collection("cities").where("capital", isEqualTo: true).get().then(
      (res) => print("Successfully completed"),
      onError: (e) => print("Error completing: $e"),
    );
firestore.dart
Java
// asynchronously retrieve multiple documents
ApiFuture<QuerySnapshot> future = db.collection("cities").whereEqualTo("capital", true).get();
// future.get() blocks on response
List<QueryDocumentSnapshot> documents = future.get().getDocuments();
for (DocumentSnapshot document : documents) {
  System.out.println(document.getId() + " => " + document.toObject(City.class));
}
RetrieveDataSnippets.java
Python
# Note: Use of CollectionRef stream() is prefered to get()
docs = db.collection(u'cities').where(u'capital', u'==', True).stream()

for doc in docs:
    print(f'{doc.id} => {doc.to_dict()}')
snippets.py
Python
(Async)
# Note: Use of CollectionRef stream() is prefered to get()
docs = db.collection("cities").where("capital", "==", True).stream()

async for doc in docs:
    print(f"{doc.id} => {doc.to_dict()}")
snippets.py
C++
db->Collection("cities")
    .WhereEqualTo("capital", FieldValue::Boolean(true))
    .Get()
    .OnCompletion([](const Future<QuerySnapshot>& future) {
      if (future.error() == Error::kErrorOk) {
        for (const DocumentSnapshot& document :
             future.result()->documents()) {
          std::cout << document << std::endl;
        }
      } else {
        std::cout << "Error getting documents: " << future.error_message()
                  << std::endl;
      }
    });
snippets.cpp
Node.js
const citiesRef = db.collection('cities');
const snapshot = await citiesRef.where('capital', '==', true).get();
if (snapshot.empty) {
  console.log('No matching documents.');
  return;
}

snapshot.forEach(doc => {
  console.log(doc.id, '=>', doc.data());
});
index.js
Einfach loslegen (Go)
fmt.Println("All capital cities:")
iter := client.Collection("cities").Where("capital", "==", true).Documents(ctx)
for {
	doc, err := iter.Next()
	if err == iterator.Done {
		break
	}
	if err != nil {
		return err
	}
	fmt.Println(doc.Data())
}
retrieve.go
PHP

PHP

$citiesRef = $db->collection('samples/php/cities');
$query = $citiesRef->where('capital', '=', true);
$documents = $query->documents();
foreach ($documents as $document) {
    if ($document->exists()) {
        printf('Document data for document %s:' . PHP_EOL, $document->id());
        print_r($document->data());
        printf(PHP_EOL);
    } else {
        printf('Document %s does not exist!' . PHP_EOL, $document->id());
    }
}
Unity
Query capitalQuery = db.Collection("cities").WhereEqualTo("Capital", true);
capitalQuery.GetSnapshotAsync().ContinueWithOnMainThread(task => {
  QuerySnapshot capitalQuerySnapshot = task.Result;
  foreach (DocumentSnapshot documentSnapshot in capitalQuerySnapshot.Documents) {
    Debug.Log(String.Format("Document data for {0} document:", documentSnapshot.Id));
    Dictionary<string, object> city = documentSnapshot.ToDictionary();
    foreach (KeyValuePair<string, object> pair in city) {
      Debug.Log(String.Format("{0}: {1}", pair.Key, pair.Value));
    }

    // Newline to separate entries
    Debug.Log("");
  };
});
C#
Query capitalQuery = db.Collection("cities").WhereEqualTo("Capital", true);
QuerySnapshot capitalQuerySnapshot = await capitalQuery.GetSnapshotAsync();
foreach (DocumentSnapshot documentSnapshot in capitalQuerySnapshot.Documents)
{
    Console.WriteLine("Document data for {0} document:", documentSnapshot.Id);
    Dictionary<string, object> city = documentSnapshot.ToDictionary();
    foreach (KeyValuePair<string, object> pair in city)
    {
        Console.WriteLine("{0}: {1}", pair.Key, pair.Value);
    }
    Console.WriteLine("");
}
Program.cs
Ruby
cities_ref = firestore.col collection_path

query = cities_ref.where "capital", "=", true

query.get do |city|
  puts "#{city.document_id} data: #{city.data}."
end
get_data.rb

Weitere Informationen zum Abrufen von Abfrageergebnissen finden Sie unter Daten abrufen. Sie können einer Abfrage auch einen Listener hinzufügen, um die aktuellen Ergebnisse abzurufen und auf zukünftige Aktualisierungen zu überwachen.

Abfrageoperatoren

Die Methode where() benötigt drei Parameter: ein Feld zum Filtern, einen Vergleichs-Operator und einen Wert. Firestore unterstützt die folgenden Vergleichsoperatoren:

Beispiel:

Webversion 9

const stateQuery = query(citiesRef, where("state", "==", "CA"));
const populationQuery = query(citiesRef, where("population", "<", 100000));
const nameQuery = query(citiesRef, where("name", ">=", "San Francisco"));
example_filters.js

Webversion 8

const stateQuery = citiesRef.where("state", "==", "CA");
const populationQuery = citiesRef.where("population", "<", 100000);
const nameQuery = citiesRef.where("name", ">=", "San Francisco");
test.firestore.js
Swift
Hinweis: Dieses Produkt nicht ist auf WatchOS- und App Clip-Zielen verfügbar. 
let stateQuery = citiesRef.whereField("state", isEqualTo: "CA")
let populationQuery = citiesRef.whereField("population", isLessThan: 100000)
let nameQuery = citiesRef.whereField("name", isGreaterThanOrEqualTo: "San Francisco")
ViewController.swift
Objective-C
Hinweis: Dieses Produkt nicht ist auf WatchOS- und App Clip-Zielen verfügbar. 
FIRQuery *stateQuery = [citiesRef queryWhereField:@"state" isEqualTo:@"CA"];
FIRQuery *populationQuery = [citiesRef queryWhereField:@"population" isLessThan:@100000];
FIRQuery *nameQuery = [citiesRef queryWhereField:@"name" isGreaterThanOrEqualTo:@"San Francisco"];
ViewController.m
Kotlin+KTX
Android
val stateQuery = citiesRef.whereEqualTo("state", "CA")
val populationQuery = citiesRef.whereLessThan("population", 100000)
val nameQuery = citiesRef.whereGreaterThanOrEqualTo("name", "San Francisco")
DocSnippets.kt
Java
Android
Query stateQuery = citiesRef.whereEqualTo("state", "CA");
Query populationQuery = citiesRef.whereLessThan("population", 100000);
Query nameQuery = citiesRef.whereGreaterThanOrEqualTo("name", "San Francisco");
DocSnippets.java

Dart

final citiesRef = db.collection("cities");
final stateQuery = citiesRef.where("state", isEqualTo: "CA");
final populationQuery = citiesRef.where("population", isLessThan: 100000);
final nameQuery = citiesRef.where("name", isEqualTo: "San Francisco");
firestore.dart
Java
Query stateQuery = cities.whereEqualTo("state", "CA");
Query populationQuery = cities.whereLessThan("population", 1000000L);
Query nameQuery = cities.whereGreaterThanOrEqualTo("name", "San Francisco");
QueryDataSnippets.java
Python
cities_ref = db.collection(u'cities')

cities_ref.where(u'state', u'==', u'CA')
cities_ref.where(u'population', u'<', 1000000)
cities_ref.where(u'name', u'>=', u'San Francisco')
snippets.py
Python
(Async)
cities_ref = db.collection("cities")

cities_ref.where("state", "==", "CA")
cities_ref.where("population", "<", 1000000)
cities_ref.where("name", ">=", "San Francisco")
snippets.py
C++
cities_ref.WhereEqualTo("state", FieldValue::String("CA"));
cities_ref.WhereLessThan("population", FieldValue::Integer(100000));
cities_ref.WhereGreaterThanOrEqualTo("name",
                                     FieldValue::String("San Francisco"));
snippets.cpp
Node.js
const stateQueryRes = await citiesRef.where('state', '==', 'CA').get();
const populationQueryRes = await citiesRef.where('population', '<', 1000000).get();
const nameQueryRes = await citiesRef.where('name', '>=', 'San Francisco').get();
index.js
Einfach loslegen (Go)
countryQuery := cities.Where("state", "==", "CA")
popQuery := cities.Where("population", "<", 1000000)
cityQuery := cities.Where("name", ">=", "San Francisco")
query.go
PHP
$stateQuery = $citiesRef->where('state', '=', 'CA');
$populationQuery = $citiesRef->where('population', '>', 1000000);
$nameQuery = $citiesRef->where('name', '>=', 'San Francisco');
query_filter_single_examples.php
Unity
Query stateQuery = citiesRef.WhereEqualTo("State", "CA");
Query populationQuery = citiesRef.WhereGreaterThan("Population", 1000000);
Query nameQuery = citiesRef.WhereGreaterThanOrEqualTo("Name", "San Francisco");
C#
Query stateQuery = citiesRef.WhereEqualTo("State", "CA");
Query populationQuery = citiesRef.WhereGreaterThan("Population", 1000000);
Query nameQuery = citiesRef.WhereGreaterThanOrEqualTo("Name", "San Francisco");
Program.cs
Ruby
state_query      = cities_ref.where "state", "=", "CA"
population_query = cities_ref.where "population", ">", 1_000_000
name_query       = cities_ref.where "name", ">=", "San Francisco"
query_data.rb

Ungleich (!=)

Mit dem Operator „ungleich“ (!=) werden Dokumente zurückgegeben, in denen das angegebene Feld vorhanden ist und es nicht mit dem Vergleichswert übereinstimmt. Beispiel:

Webversion 9

const notCapitalQuery = query(citiesRef, where("capital", "!=", false));
simple_query_not_equal.js

Webversion 8

citiesRef.where("capital", "!=", false);
test.firestore.js
Swift
Hinweis: Dieses Produkt nicht ist auf WatchOS- und App Clip-Zielen verfügbar. 
let notEqualQuery = citiesRef.whereField("capital", isNotEqualTo: false)
ViewController.swift
Objective-C
Hinweis: Dieses Produkt nicht ist auf WatchOS- und App Clip-Zielen verfügbar. 
query = [citiesRef queryWhereField:@"capital" isNotEqualTo:@NO];
ViewController.m
Kotlin+KTX
Android
val notCapitalQuery = citiesRef.whereNotEqualTo("capital", false)
DocSnippets.kt
Java
Android
Query notCapitalQuery = citiesRef.whereNotEqualTo("capital", false);
DocSnippets.java

Dart

final citiesRef = db.collection("cities");
final notCapitals = citiesRef.where("capital", isNotEqualTo: true);
firestore.dart
Java
CollectionReference citiesRef = db.collection("cities");

Query query = citiesRef.whereNotEqualTo("capital", false);
QueryDataSnippets.java
Python
// Snippet not yet available
C++
// Snippet not yet available
Node.js
const capitalNotFalseRes = await citiesRef.where('capital', '!=', false).get();
index.js
Einfach loslegen (Go)
// Snippet not yet available
PHP
$stateQuery = $citiesRef->where('capital', '!=', false);
query_filter_not_eq.php
Unity
// Snippet not yet available
C#
// Snippet not yet available
Ruby
cities_ref = firestore.col collection_path
query = cities_ref.where "capital", "!=", false
query_data.rb

Diese Abfrage gibt alle city-Dokumente zurück, in denen das Feld capital mit einem anderen Wert als false oder null vorhanden ist. Dazu gehören city-Dokumente, deren capital-Feldwert gleich true oder einem beliebigen nicht-boolesche Wert außer null ist.

Diese Abfrage gibt keine city-Dokumente zurück, in denen das Feld capital nicht vorhanden ist. Ungleiche (!=)- und not-in-Abfragen schließen Dokumente aus, bei denen das angegebene Feld nicht vorhanden ist.

Ein Feld ist vorhanden, wenn es auf einen beliebigen Wert gesetzt ist, einschließlich einer leeren Zeichenfolge (""), null und NaN (keine Zahl). Die null-Feldwerte stimmen nicht mit den !=-Klauseln überein, da x != null als undefined ausgewertet wird.

Beschränkungen

Beachten Sie folgende Einschränkungen für !=-Abfragen:

  • Nur Dokumente, in denen das angegebene Feld vorhanden ist, können mit der Abfrage übereinstimmen.
  • not-in und != können nicht in zusammengesetzten Abfragen kombiniert werden.
  • In zusammengesetzten Abfragen müssen alle Bereichs- (<, <=, >, >=) und Ungleich-Vergleiche (!=, not-in) in demselben Feld filtern.

Arraymitgliedschaft

Mit dem Operator array-contains können Sie auf Basis von Arraywerten filtern. Beispiel:

Webversion 9

import { query, where } from "firebase/firestore";
const q = query(citiesRef, where("regions", "array-contains", "west_coast"));
array_contains_filter.js

Webversion 8

citiesRef.where("regions", "array-contains", "west_coast");
test.firestore.js
Swift
Hinweis: Dieses Produkt nicht ist auf WatchOS- und App Clip-Zielen verfügbar. 
citiesRef
  .whereField("regions", arrayContains: "west_coast")
ViewController.swift
Objective-C
Hinweis: Dieses Produkt nicht ist auf WatchOS- und App Clip-Zielen verfügbar. 
[citiesRef queryWhereField:@"state" arrayContains:@"west_coast"];
ViewController.m
Kotlin+KTX
Android
val citiesRef = db.collection("cities")

citiesRef.whereArrayContains("regions", "west_coast")
DocSnippets.kt
Java
Android
CollectionReference citiesRef = db.collection("cities");

citiesRef.whereArrayContains("regions", "west_coast");
DocSnippets.java

Dart

final citiesRef = db.collection("cities");
final westCoastcities =
    citiesRef.where("regions", arrayContains: "west_coast");
firestore.dart
Java
CollectionReference citiesRef = db.collection("cities");
Query westCoastQuery = citiesRef.whereArrayContains("regions", "west_coast");
QueryDataSnippets.java
Python
cities_ref = db.collection(u'cities')

query = cities_ref.where(u'regions', u'array_contains', u'west_coast')
snippets.py
Python
(Async)
cities_ref = db.collection("cities")

query = cities_ref.where("regions", "array_contains", "west_coast")
snippets.py
C++
CollectionReference cities_ref = db->Collection("cities");

cities_ref.WhereArrayContains("region", FieldValue::String("west_coast"));
snippets.cpp
Node.js
const westCoastCities = citiesRef.where('regions', 'array-contains',
  'west_coast').get();
index.js
Einfach loslegen (Go)
query := cities.Where("regions", "array-contains", "west_coast").Documents(ctx)
query.go
PHP
$containsQuery = $citiesRef->where('regions', 'array-contains', 'west_coast');
query_filter_array_contains.php
Unity
CollectionReference citiesRef = db.Collection("cities");
Query arrayContainsQuery = citiesRef.WhereArrayContains("region", "west_coast");
C#
Query query = citiesRef.WhereArrayContains("Regions", "west_coast");
Program.cs
Ruby
cities_ref = firestore.col collection_path
cities = cities_ref.where "regions", "array-contains", "west_coast"
query_data.rb

Diese Abfrage gibt jedes city-Dokument zurück, in dem das Feld regions ein Array ist, das west_coast enthält. Wenn das Array mehrere Instanzen des abgefragten Werts enthält, wird das Dokument nur einmal in die Ergebnisse aufgenommen.

Sie können pro Abfrage höchstens eine array-contains-Klausel verwenden. Sie können array-contains nicht mit array-contains-any kombinieren.

in, not-in und array-contains-any

Mit dem Operator in können Sie bis zu 10 Gleichheitsklauseln (==) für dasselbe Feld mit einem logischen OR kombinieren. Eine in-Abfrage gibt Dokumente zurück, bei denen das angegebene Feld mit einem der Vergleichswerte übereinstimmt. Beispiel:

Webversion 9

import { query, where } from "firebase/firestore";

const q = query(citiesRef, where('country', 'in', ['USA', 'Japan']));
in_filter.js

Webversion 8

citiesRef.where('country', 'in', ['USA', 'Japan']);
test.firestore.js
Swift
Hinweis: Dieses Produkt nicht ist auf WatchOS- und App Clip-Zielen verfügbar. 
let citiesRef = db.collection("cities")

citiesRef.whereField("country", in: ["USA", "Japan"])
ViewController.swift
Objective-C
Hinweis: Dieses Produkt nicht ist auf WatchOS- und App Clip-Zielen verfügbar. 
FIRCollectionReference *citiesRef = [self.db collectionWithPath:@"cities"];

[citiesRef queryWhereField:@"country" in:@[@"USA", @"Japan"]];
ViewController.m
Kotlin+KTX
Android
val citiesRef = db.collection("cities")

citiesRef.whereIn("country", listOf("USA", "Japan"))
DocSnippets.kt
Java
Android
CollectionReference citiesRef = db.collection("cities");

citiesRef.whereIn("country", Arrays.asList("USA", "Japan"));
DocSnippets.java

Dart

final citiesRef = db.collection("cities");
final cities = citiesRef.where("country", whereIn: ["USA", "Japan"]);
firestore.dart
Java
CollectionReference citiesRef = db.collection("cities");

Query query = citiesRef.whereIn("country", Arrays.asList("USA", "Japan"));
QueryDataSnippets.java
Python
cities_ref = db.collection(u'cities')

query = cities_ref.where(u'country', u'in', [u'USA', u'Japan'])
return query
snippets.py
Python
(Async)
cities_ref = db.collection("cities")

query = cities_ref.where("country", "in", ["USA", "Japan"])
return query
snippets.py
C++
CollectionReference cities_ref = db->Collection("cities");

cities_ref.WhereIn("country", std::vector<FieldValue> {
  FieldValue::String("USA"),
  FieldValue::String("Japan")
});
snippets.cpp
Node.js
const usaOrJapan = await citiesRef.where('country', 'in', ['USA', 'Japan']).get();
index.js
Einfach loslegen (Go)
cities := client.Collection("cities")
query := cities.Where("country", "in", []string{"USA", "Japan"}).Documents(ctx)
query.go
PHP
$rangeQuery = $citiesRef->where('country', 'in', ['USA', 'Japan']);
query_filter_in.php
Unity
CollectionReference citiesRef = db.Collection("cities");
List countriesList = new List<object>() {"USA", "Japan"};

Query whereInQuery = citiesRef.WhereIn("country", countriesList);
C#
Query query = citiesRef.WhereIn("Country", new[] { "USA", "Japan" });
Program.cs
Ruby
cities_ref = firestore.col collection_path
usr_or_japan = cities_ref.where "country", "in", ["USA", "Japan"]
query_data.rb

Diese Abfrage gibt alle city-Dokumente zurück, bei denen das Feld country auf USA oder Japan gesetzt ist. Aus den Beispieldaten gehören die Dokumente SF, LA, DC und TOK dazu.

not-in

Mit dem Operator not-in können Sie bis zu 10 Nicht-Gleichheitsklauseln (!=) für dasselbe Feld mit einem logischen AND kombinieren. Eine not-in-Abfrage gibt Dokumente zurück, in denen das angegebene Feld vorhanden ist, nicht null ist und keinem der Vergleichswerte entspricht. Beispiel:

Webversion 9

import { query, where } from "firebase/firestore";

const q = query(citiesRef, where('country', 'not-in', ['USA', 'Japan']));
not_in_filter.js

Webversion 8

citiesRef.where('country', 'not-in', ['USA', 'Japan']);
test.firestore.js
Swift
Hinweis: Dieses Produkt nicht ist auf WatchOS- und App Clip-Zielen verfügbar. 
citiesRef.whereField("country", notIn: ["USA", "Japan"])
ViewController.swift
Objective-C
Hinweis: Dieses Produkt nicht ist auf WatchOS- und App Clip-Zielen verfügbar. 
[citiesRef queryWhereField:@"country" notIn:@[@"USA", @"Japan"]];
ViewController.m
Kotlin+KTX
Android
citiesRef.whereNotIn("country", listOf("USA", "Japan"))
DocSnippets.kt
Java
Android
citiesRef.whereNotIn("country", Arrays.asList("USA", "Japan"));
DocSnippets.java

Dart

final citiesRef = db.collection("cities");
final cities = citiesRef.where("country", whereNotIn: ["USA", "Japan"]);
firestore.dart
Java
CollectionReference citiesRef = db.collection("cities");

Query query = citiesRef.whereNotIn("country", Arrays.asList("USA", "Japan"));
QueryDataSnippets.java
Python
// Snippet not yet available
C++
cities_ref.WhereNotIn("country", std::vector<FieldValue> {
  FieldValue::String("USA"),
  FieldValue::String("Japan")
});
snippets.cpp
Node.js
const notUsaOrJapan = await citiesRef.where('country', 'not-in', ['USA', 'Japan']).get();
index.js
Einfach loslegen (Go)
// Snippet not yet available
PHP
$stateQuery = $citiesRef->where(
    'country',
    \Google\Cloud\Firestore\V1\StructuredQuery\FieldFilter\Operator::NOT_IN,
    ['USA', 'Japan']
);
query_filter_not_in.php
Unity
// Snippet not yet available
C#
// Snippet not yet available
Ruby
cities_ref = firestore.col collection_path
usr_or_japan = cities_ref.where "country", "not_in", ["USA", "Japan"]
query_data.rb

Diese Abfrage gibt alle city-Dokumente zurück, in denen das Feld country vorhanden und nicht auf USA, Japan oder null festgelegt ist. Aus den Beispieldaten gehören die Dokumente London, Hong Kong und dazu.

not-in-Abfragen schließen Dokumente aus, in denen das angegebene Feld nicht vorhanden ist. Ein Feld ist vorhanden, wenn es auf einen beliebigen Wert gesetzt ist, einschließlich einer leeren Zeichenfolge (""), null und NaN (keine Zahl). x != null ergibt undefined. Eine not-in-Abfrage mit null als einer der Vergleichswerte stimmt mit keinem Dokument überein.

array-contains-any

Mit dem Operator array-contains-any können Sie bis zu 10 array-contains-Klauseln für dasselbe Feld mit einem logischen OR kombinieren. Eine Abfrage wie array-contains-any gibt Dokumente zurück, bei denen das angegebene Feld ein Array ist, das mindestens einen der Vergleichswerte enthält:

Webversion 9

import { query, where } from "firebase/firestore";

const q = query(citiesRef,
  where('regions', 'array-contains-any', ['west_coast', 'east_coast']));
array_contains_any_filter.js

Webversion 8

citiesRef.where('regions', 'array-contains-any',
    ['west_coast', 'east_coast']);
test.firestore.js
Swift
Hinweis: Dieses Produkt nicht ist auf WatchOS- und App Clip-Zielen verfügbar. 
let citiesRef = db.collection("cities")
citiesRef.whereField("regions", arrayContainsAny: ["west_coast", "east_coast"])
ViewController.swift
Objective-C
Hinweis: Dieses Produkt nicht ist auf WatchOS- und App Clip-Zielen verfügbar. 
FIRCollectionReference *citiesRef = [self.db collectionWithPath:@"cities"];

[citiesRef queryWhereField:@"regions" arrayContainsAny:@[@"west_coast", @"east_coast"]];
ViewController.m
Kotlin+KTX
Android
val citiesRef = db.collection("cities")

citiesRef.whereArrayContainsAny("regions", listOf("west_coast", "east_coast"))
DocSnippets.kt
Java
Android
CollectionReference citiesRef = db.collection("cities");

citiesRef.whereArrayContainsAny("regions", Arrays.asList("west_coast", "east_coast"));
DocSnippets.java

Dart

final citiesRef = db.collection("cities");
final cities = citiesRef
    .where("regions", arrayContainsAny: ["west_coast", "east_coast"]);
firestore.dart
Java
CollectionReference citiesRef = db.collection("cities");

Query query =
    citiesRef.whereArrayContainsAny("regions", Arrays.asList("west_coast", "east_coast"));
QueryDataSnippets.java
Python
cities_ref = db.collection(u'cities')

query = cities_ref.where(
    u'regions', u'array_contains_any', [u'west_coast', u'east_coast']
)
return query
snippets.py
Python
(Async)
cities_ref = db.collection("cities")

query = cities_ref.where(
    "regions", "array_contains_any", ["west_coast", "east_coast"]
)
return query
snippets.py
C++
CollectionReference cities_ref = db->Collection("cities");

cities_ref.WhereArrayContainsAny("region", std::vector<FieldValue> {
  FieldValue::String("west_coast"),
  FieldValue::String("east_coast")
});
snippets.cpp
Node.js
const coastalCities = await citiesRef.where('regions', 'array-contains-any',
    ['west_coast', 'east_coast']).get();
index.js
Einfach loslegen (Go)
cities := client.Collection("cities")
query := cities.Where("regions", "array-contains-any", []string{"west_coast", "east_coast"}).Documents(ctx)
query.go
PHP
$containsQuery = $citiesRef->where('regions', 'array-contains-any', ['west_coast', 'east_coast']);
query_filter_array_contains_any.php
Unity
CollectionReference citiesRef = db.Collection("cities");
List regionsList = new List<object>() {"west_coast", "east_coast"};

Query arrayContainsAnyQuery = citiesRef.WhereArrayContainsAny("regions", regionsList);
C#
Query query = citiesRef.WhereArrayContainsAny("Regions", new[] { "west_coast", "east_coast" });
Program.cs
Ruby
cities_ref = firestore.col collection_path
costal_cities = cities_ref.where "regions", "array-contains-any", ["west_coast", "east_coast"]
query_data.rb

Diese Abfrage gibt jedes "city"-Dokument zurück, in dem das Feld regions ein Array mit west_coast oder east_coast ist. Aus den Beispieldaten gehören die Dokumente SF, LA und DC dazu.

Ergebnisse aus array-contains-any werden entfernt. Auch wenn das Arrayfeld eines Dokuments mit mehreren der Vergleichswerte übereinstimmt, enthält die Ergebnismenge dieses Dokument nur einmal.

array-contains-any filtert immer nach dem Arraydatentyp. Die obige Abfrage würde beispielsweise kein "city"-Dokument zurückgeben, in dem anstelle eines Arrays das Feld regions der String west_coast ist.

Sie können einen Arraywert als Vergleichswert für in verwenden. Im Gegensatz zu array-contains-any stimmt die Klausel aber mit einer genauen Übereinstimmung von Arraylänge, -reihenfolge und -werten überein. Beispiel:

Webversion 9

import { query, where } from "firebase/firestore";

const q = query(citiesRef, where('regions', 'in', [['west_coast', 'east_coast']]));
in_filter_with_array.js

Webversion 8

citiesRef.where('regions', 'in',
    [['west_coast', 'east_coast']]);
test.firestore.js
Swift
Hinweis: Dieses Produkt nicht ist auf WatchOS- und App Clip-Zielen verfügbar. 
citiesRef.whereField("regions", in: [["west_coast"], ["east_coast"]]);
ViewController.swift
Objective-C
Hinweis: Dieses Produkt nicht ist auf WatchOS- und App Clip-Zielen verfügbar. 
[citiesRef queryWhereField:@"regions" in:@[@[@"west_coast"], @[@"east_coast"]]];
ViewController.m
Kotlin+KTX
Android
citiesRef.whereIn("regions", listOf(arrayOf("west_coast"), arrayOf("east_coast")))
DocSnippets.kt
Java
Android
citiesRef.whereIn("regions", Arrays.asList(new String[]{"west_coast"}, new String[]{"east_coast"}));
DocSnippets.java

Dart

final citiesRef = db.collection("cities");
final cities = citiesRef.where("regions", whereIn: [
  ["west_coast"],
  ["east_coast"]
]);
firestore.dart
Java
CollectionReference citiesRef = db.collection("cities");

Query query =
    citiesRef.whereIn(
        "regions", Arrays.asList(Arrays.asList("west_coast"), Arrays.asList("east_coast")));
QueryDataSnippets.java
Python
cities_ref = db.collection(u'cities')

query = cities_ref.where(
    u'regions', u'in', [[u'west_coast'], [u'east_coast']]
)
return query
snippets.py
Python
(Async)
cities_ref = db.collection("cities")

query = cities_ref.where("regions", "in", [["west_coast"], ["east_coast"]])
return query
snippets.py
C++
cities_ref.WhereIn("region", std::vector<FieldValue> {
  FieldValue::String("west_coast"),
  FieldValue::String("east_coast")
});
snippets.cpp
Node.js
const exactlyOneCoast = await citiesRef.where('regions', 'in',
    [['west_coast', 'east_coast']]).get();
index.js
Einfach loslegen (Go)
cities := client.Collection("cities")
query := cities.Where("regions", "in", [][]string{{"west_coast"}, {"east_coast"}}).Documents(ctx)
query.go
PHP
$rangeQuery = $citiesRef->where('regions', 'in', [['west_coast'], ['east_coast']]);
query_filter_in_with_array.php
Unity
// Not yet supported in the Unity SDK
C#
Query query = citiesRef.WhereIn("Regions",
    new[] { new[] { "west_coast" }, new[] { "east_coast" } });
Program.cs
Ruby
cities_ref = firestore.col collection_path
exactly_one_cost = cities_ref.where "regions", "in", [["west_coast"], ["east_coast"]]
query_data.rb

Diese Abfrage gibt jedes "city"-Dokument zurück, in dem das Feld regions ein Array ist, das genau ein Element von entweder west_coast oder east_coast enthält. Aus den Beispieldaten entspricht nur das Dokument DC mit dem Feld regions von ["east_coast"] diesen Angaben. Das SF-Dokument stimmt jedoch nicht überein, da das Feld regions den Wert ["west_coast", "norcal"] enthält.

Beschränkungen

Beachten Sie die folgenden Einschränkungen für in, not-in und array-contains-any:

  • in, not-in und array-contains-any unterstützen bis zu zehn Vergleichswerte.
  • Sie können pro Abfrage höchstens eine array-contains-Klausel verwenden. Sie können array-contains nicht mit array-contains-any kombinieren.
  • Sie können pro Abfrage höchstens eine in-, not-in- oder array-contains-any-Klausel verwenden. Diese Operatoren können nicht in derselben Abfrage kombiniert werden.
  • Sie können not-in nicht mit ungleich != kombinieren.
  • Sie können Ihre Abfrage nicht nach einem Feld sortieren, das in einer Gleichheitsklausel (==) oder einer in-Klausel enthalten ist.

Kumulierende Abfragen

Sie können mehrere Gleichheitsoperatoren (== oder array-contains) verketten, um spezifischere Abfragen zu erstellen (logisches AND). Sie müssen jedoch einen zusammengesetzten Index erstellen, um Gleichheitsoperatoren mit den Ungleichheitsfiltern <, <=, > und != zu kombinieren.

Webversion 9

import { query, where } from "firebase/firestore";

const q1 = query(citiesRef, where("state", "==", "CO"), where("name", "==", "Denver"));
const q2 = query(citiesRef, where("state", "==", "CA"), where("population", "<", 1000000));
chain_filters.js

Webversion 8

const q1 = citiesRef.where("state", "==", "CO").where("name", "==", "Denver");
const q2 = citiesRef.where("state", "==", "CA").where("population", "<", 1000000);
test.firestore.js
Swift
Hinweis: Dieses Produkt nicht ist auf WatchOS- und App Clip-Zielen verfügbar. 
citiesRef
    .whereField("state", isEqualTo: "CO")
    .whereField("name", isEqualTo: "Denver")
citiesRef
    .whereField("state", isEqualTo: "CA")
    .whereField("population", isLessThan: 1000000)
ViewController.swift
Objective-C
Hinweis: Dieses Produkt nicht ist auf WatchOS- und App Clip-Zielen verfügbar. 
[[citiesRef queryWhereField:@"state" isEqualTo:@"CO"]
    queryWhereField:@"name" isGreaterThanOrEqualTo:@"Denver"];
[[citiesRef queryWhereField:@"state" isEqualTo:@"CA"]
    queryWhereField:@"population" isLessThan:@1000000];
ViewController.m
Kotlin+KTX
Android
citiesRef.whereEqualTo("state", "CO").whereEqualTo("name", "Denver")
citiesRef.whereEqualTo("state", "CA").whereLessThan("population", 1000000)
DocSnippets.kt
Java
Android
citiesRef.whereEqualTo("state", "CO").whereEqualTo("name", "Denver");
citiesRef.whereEqualTo("state", "CA").whereLessThan("population", 1000000);
DocSnippets.java

Dart

final citiesRef = db.collection("cities");
citiesRef
    .where("state", isEqualTo: "CO")
    .where("name", isEqualTo: "Denver");
citiesRef
    .where("state", isEqualTo: "CA")
    .where("population", isLessThan: 1000000);
firestore.dart
Java
Query chainedQuery1 = cities.whereEqualTo("state", "CO").whereEqualTo("name", "Denver");
QueryDataSnippets.java
Python
cities_ref = db.collection(u'cities')

denver_query = cities_ref.where(
    u'state', u'==', u'CO').where(u'name', u'==', u'Denver')
large_us_cities_query = cities_ref.where(
    u'state', u'==', u'CA').where(u'population', u'>', 1000000)
snippets.py
Python
(Async)
cities_ref = db.collection("cities")

denver_query = cities_ref.where("state", "==", "CO").where("name", "==", "Denver")
large_us_cities_query = cities_ref.where("state", "==", "CA").where(
    "population", ">", 1000000
)
snippets.py
C++
cities_ref.WhereEqualTo("state", FieldValue::String("CO"))
    .WhereEqualTo("name", FieldValue::String("Denver"));
cities_ref.WhereEqualTo("state", FieldValue::String("CA"))
    .WhereLessThan("population", FieldValue::Integer(1000000));
snippets.cpp
Node.js
citiesRef.where('state', '==', 'CO').where('name', '==', 'Denver');
citiesRef.where('state', '==', 'CA').where('population', '<', 1000000);
index.js
Einfach loslegen (Go)
denverQuery := cities.Where("name", "==", "Denver").Where("state", "==", "CO")
caliQuery := cities.Where("state", "==", "CA").Where("population", "<=", 1000000)
query := cities.Where("country", "==", "USA").Where("population", ">", 5000000)
query.go
PHP
$chainedQuery = $citiesRef
    ->where('state', '=', 'CA')
    ->where('name', '=', 'San Francisco');
query_filter_compound_multi_eq.php
Unity
Query chainedQuery = citiesRef
    .WhereEqualTo("State", "CA")
    .WhereEqualTo("Name", "San Francisco");
C#
Query chainedQuery = citiesRef
    .WhereEqualTo("State", "CA")
    .WhereEqualTo("Name", "San Francisco");
Program.cs
Ruby
chained_query = cities_ref.where("state", "=", "CA").where("name", "=", "San Francisco")
query_data.rb

Sie können einen Bereichs- (<, <=, >, >=) oder Nicht-Gleichheitsvergleich (!=) nur auf einem einzelnen Feld ausführen. Es können maximal eine array-contains- oder array-contains-any-Klausel in einer zusammengesetzten Abfrage sein:

Gültig: Bereichsfilter für nur ein Feld

Webversion 9

import { query, where } from "firebase/firestore";

const q1 = query(citiesRef, where("state", ">=", "CA"), where("state", "<=", "IN"));
const q2 = query(citiesRef, where("state", "==", "CA"), where("population", ">", 1000000));
valid_range_filters.js

Webversion 8

const q1 = citiesRef.where("state", ">=", "CA").where("state", "<=", "IN");
const q2 = citiesRef.where("state", "==", "CA").where("population", ">", 1000000);
test.firestore.js
Swift
Hinweis: Dieses Produkt nicht ist auf WatchOS- und App Clip-Zielen verfügbar. 
citiesRef
    .whereField("state", isGreaterThanOrEqualTo: "CA")
    .whereField("state", isLessThanOrEqualTo: "IN")
citiesRef
    .whereField("state", isEqualTo: "CA")
    .whereField("population", isGreaterThan: 1000000)
ViewController.swift
Objective-C
Hinweis: Dieses Produkt nicht ist auf WatchOS- und App Clip-Zielen verfügbar. 
[[citiesRef queryWhereField:@"state" isGreaterThanOrEqualTo:@"CA"]
    queryWhereField:@"state" isLessThanOrEqualTo:@"IN"];
[[citiesRef queryWhereField:@"state" isEqualTo:@"CA"]
    queryWhereField:@"population" isGreaterThan:@1000000];
ViewController.m
Kotlin+KTX
Android
citiesRef.whereGreaterThanOrEqualTo("state", "CA")
        .whereLessThanOrEqualTo("state", "IN")
citiesRef.whereEqualTo("state", "CA")
        .whereGreaterThan("population", 1000000)
DocSnippets.kt
Java
Android
citiesRef.whereGreaterThanOrEqualTo("state", "CA")
        .whereLessThanOrEqualTo("state", "IN");
citiesRef.whereEqualTo("state", "CA")
        .whereGreaterThan("population", 1000000);
DocSnippets.java

Dart

final citiesRef = db.collection("cities");
citiesRef
    .where("state", isGreaterThanOrEqualTo: "CA")
    .where("state", isLessThanOrEqualTo: "IN");
citiesRef
    .where("state", isEqualTo: "CA")
    .where("population", isGreaterThan: 1000000);
firestore.dart
Java
Query validQuery1 =
    cities.whereGreaterThanOrEqualTo("state", "CA").whereLessThanOrEqualTo("state", "IN");
Query validQuery2 = cities.whereEqualTo("state", "CA").whereGreaterThan("population", 1000000);
QueryDataSnippets.java
Python
cities_ref = db.collection(u'cities')
cities_ref.where(u'state', u'>=', u'CA').where(u'state', u'<=', u'IN')
snippets.py
Python
(Async)
cities_ref = db.collection("cities")
cities_ref.where("state", ">=", "CA").where("state", "<=", "IN")
snippets.py
C++
cities_ref.WhereGreaterThanOrEqualTo("state", FieldValue::String("CA"))
    .WhereLessThanOrEqualTo("state", FieldValue::String("IN"));
cities_ref.WhereEqualTo("state", FieldValue::String("CA"))
    .WhereGreaterThan("population", FieldValue::Integer(1000000));
snippets.cpp
Node.js
citiesRef.where('state', '>=', 'CA').where('state', '<=', 'IN');
citiesRef.where('state', '==', 'CA').where('population', '>', 1000000);
index.js
Einfach loslegen (Go)
stateQuery := cities.Where("state", ">=", "CA").Where("state", "<", "IN")
populationQuery := cities.Where("state", "==", "CA").Where("population", ">", 1000000)
query.go
PHP
$rangeQuery = $citiesRef
    ->where('state', '>=', 'CA')
    ->where('state', '<=', 'IN');
query_filter_range_valid.php
Unity
Query rangeQuery = citiesRef
    .WhereGreaterThanOrEqualTo("State", "CA")
    .WhereLessThanOrEqualTo("State", "IN");
C#
Query rangeQuery = citiesRef
    .WhereGreaterThanOrEqualTo("State", "CA")
    .WhereLessThanOrEqualTo("State", "IN");
Program.cs
Ruby
range_query = cities_ref.where("state", ">=", "CA").where("state", "<=", "IN")
query_data.rb

Ungültig: Bereichsfilter für verschiedene Felder

Webversion 9

import { query, where } from "firebase/firestore";

const q = query(citiesRef, where("state", ">=", "CA"), where("population", ">", 100000));
invalid_range_filters.js

Webversion 8

citiesRef.where("state", ">=", "CA").where("population", ">", 100000);
test.firestore.js
Swift
Hinweis: Dieses Produkt nicht ist auf WatchOS- und App Clip-Zielen verfügbar.
Hinweis: Dieses Produkt nicht ist auf WatchOS- und App Clip-Zielen verfügbar. 
citiesRef
    .whereField("state", isGreaterThanOrEqualTo: "CA")
    .whereField("population", isGreaterThan: 1000000)
ViewController.swift
Objective-C
Hinweis: Dieses Produkt nicht ist auf WatchOS- und App Clip-Zielen verfügbar. 
[[citiesRef queryWhereField:@"state" isGreaterThanOrEqualTo:@"CA"]
    queryWhereField:@"population" isGreaterThan:@1000000];
ViewController.m
Kotlin+KTX
Android
citiesRef.whereGreaterThanOrEqualTo("state", "CA")
        .whereGreaterThan("population", 100000)
DocSnippets.kt
Java
Android
citiesRef.whereGreaterThanOrEqualTo("state", "CA").whereGreaterThan("population", 100000);
DocSnippets.java

Dart

final citiesRef = db.collection("cities");
citiesRef
    .where("state", isGreaterThanOrEqualTo: "CA")
    .where("population", isGreaterThan: 1000000);
firestore.dart
Java
Query invalidRangeQuery =
    cities.whereGreaterThanOrEqualTo("state", "CA").whereGreaterThan("population", 100000);
QueryDataSnippets.java
Python
cities_ref = db.collection(u'cities')
cities_ref.where(
    u'state', u'>=', u'CA').where(u'population', u'>=', 1000000)
snippets.py
Python
(Async)
cities_ref = db.collection("cities")
cities_ref.where("state", ">=", "CA").where("population", ">=", 1000000)
snippets.py
C++
// BAD EXAMPLE -- will crash the program:
cities_ref.WhereGreaterThanOrEqualTo("state", FieldValue::String("CA"))
    .WhereGreaterThan("population", FieldValue::Integer(100000));
snippets.cpp
Node.js
citiesRef.where('state', '>=', 'CA').where('population', '>', 1000000);
index.js
Einfach loslegen (Go)
query := cities.Where("state", ">=", "CA").Where("population", ">", 1000000)
query.go
PHP
$invalidRangeQuery = $citiesRef
    ->where('state', '>=', 'CA')
    ->where('population', '>', 1000000);
query_filter_range_invalid.php
Unity
Query invalidRangeQuery = citiesRef
    .WhereGreaterThanOrEqualTo("State", "CA")
    .WhereGreaterThan("Population", 1000000);
C#
Query invalidRangeQuery = citiesRef
    .WhereGreaterThanOrEqualTo("State", "CA")
    .WhereGreaterThan("Population", 1000000);
Program.cs
Ruby
invalid_range_query = cities_ref.where("state", ">=", "CA").where("population", ">", 1_000_000)
query_data.rb

Sammlungsgruppenabfragen

Eine Sammlungsgruppe umfasst alle Sammlungen mit derselben ID. Standardmäßig rufen Abfragen Ergebnisse aus einer einzelnen Sammlung in einer Datenbank ab. Mit einer Sammlungsgruppenabfrage können Sie Dokumente aus einer Sammlungsgruppe statt aus einer einzelnen Sammlung abrufen.

So haben Sie beispielsweise die Möglichkeit, eine landmarks-Sammlungsgruppe zu erstellen, indem Sie jeder Stadt eine Untersammlung für Sehenswürdigkeiten hinzufügen:

Webversion 9

import { collection, addDoc } from "firebase/firestore";

const citiesRef = collection(db, 'cities');

await Promise.all([
    addDoc(collection(citiesRef, 'SF', 'landmarks'), {
        name: 'Golden Gate Bridge',
        type: 'bridge'
    }),
    addDoc(collection(citiesRef, 'SF', 'landmarks'), {
        name: 'Legion of Honor',
        type: 'museum'
    }),
    addDoc(collection(citiesRef, 'LA', 'landmarks'), {
        name: 'Griffith Park',
        type: 'park'
    }),
    addDoc(collection(citiesRef, 'LA', 'landmarks'), {
        name: 'The Getty',
        type: 'museum'
    }),
    addDoc(collection(citiesRef, 'DC', 'landmarks'), {
        name: 'Lincoln Memorial',
        type: 'memorial'
    }),
    addDoc(collection(citiesRef, 'DC', 'landmarks'), {
        name: 'National Air and Space Museum',
        type: 'museum'
    }),
    addDoc(collection(citiesRef, 'TOK', 'landmarks'), {
        name: 'Ueno Park',
        type: 'park'
    }),
    addDoc(collection(citiesRef, 'TOK', 'landmarks'), {
        name: 'National Museum of Nature and Science',
        type: 'museum'
    }),
    addDoc(collection(citiesRef, 'BJ', 'landmarks'), {
        name: 'Jingshan Park',
        type: 'park'
    }),
    addDoc(collection(citiesRef, 'BJ', 'landmarks'), {
        name: 'Beijing Ancient Observatory',
        type: 'museum'
    })
]);
fs_collection_group_query_data_setup.js

Webversion 8

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

var landmarks = Promise.all([
    citiesRef.doc('SF').collection('landmarks').doc().set({
        name: 'Golden Gate Bridge',
        type: 'bridge'
    }),
    citiesRef.doc('SF').collection('landmarks').doc().set({
        name: 'Legion of Honor',
        type: 'museum'
    }),
    citiesRef.doc('LA').collection('landmarks').doc().set({
        name: 'Griffith Park',
        type: 'park'
    }),
    citiesRef.doc('LA').collection('landmarks').doc().set({
        name: 'The Getty',
        type: 'museum'
    }),
    citiesRef.doc('DC').collection('landmarks').doc().set({
        name: 'Lincoln Memorial',
        type: 'memorial'
    }),
    citiesRef.doc('DC').collection('landmarks').doc().set({
        name: 'National Air and Space Museum',
        type: 'museum'
    }),
    citiesRef.doc('TOK').collection('landmarks').doc().set({
        name: 'Ueno Park',
        type: 'park'
    }),
    citiesRef.doc('TOK').collection('landmarks').doc().set({
        name: 'National Museum of Nature and Science',
        type: 'museum'
    }),
    citiesRef.doc('BJ').collection('landmarks').doc().set({
        name: 'Jingshan Park',
        type: 'park'
    }),
    citiesRef.doc('BJ').collection('landmarks').doc().set({
        name: 'Beijing Ancient Observatory',
        type: 'museum'
    })
]);
test.firestore.js
Swift
Hinweis: Dieses Produkt nicht ist auf WatchOS- und App Clip-Zielen verfügbar. 
let citiesRef = db.collection("cities")

var data = ["name": "Golden Gate Bridge", "type": "bridge"]
citiesRef.document("SF").collection("landmarks").addDocument(data: data)

data = ["name": "Legion of Honor", "type": "museum"]
citiesRef.document("SF").collection("landmarks").addDocument(data: data)

data = ["name": "Griffith Park", "type": "park"]
citiesRef.document("LA").collection("landmarks").addDocument(data: data)

data = ["name": "The Getty", "type": "museum"]
citiesRef.document("LA").collection("landmarks").addDocument(data: data)

data = ["name": "Lincoln Memorial", "type": "memorial"]
citiesRef.document("DC").collection("landmarks").addDocument(data: data)

data = ["name": "National Air and Space Museum", "type": "museum"]
citiesRef.document("DC").collection("landmarks").addDocument(data: data)

data = ["name": "Ueno Park", "type": "park"]
citiesRef.document("TOK").collection("landmarks").addDocument(data: data)

data = ["name": "National Museum of Nature and Science", "type": "museum"]
citiesRef.document("TOK").collection("landmarks").addDocument(data: data)

data = ["name": "Jingshan Park", "type": "park"]
citiesRef.document("BJ").collection("landmarks").addDocument(data: data)

data = ["name": "Beijing Ancient Observatory", "type": "museum"]
citiesRef.document("BJ").collection("landmarks").addDocument(data: data)
ViewController.swift
Objective-C
Hinweis: Dieses Produkt nicht ist auf WatchOS- und App Clip-Zielen verfügbar. 
FIRCollectionReference *citiesRef = [self.db collectionWithPath:@"cities"];

NSDictionary *data = @{@"name": @"Golden Gate Bridge", @"type": @"bridge"};
[[[citiesRef documentWithPath:@"SF"] collectionWithPath:@"landmarks"] addDocumentWithData:data];

data = @{@"name": @"Legion of Honor", @"type": @"museum"};
[[[citiesRef documentWithPath:@"SF"] collectionWithPath:@"landmarks"] addDocumentWithData:data];

data = @{@"name": @"Griffith Park", @"type": @"park"};
[[[citiesRef documentWithPath:@"LA"] collectionWithPath:@"landmarks"] addDocumentWithData:data];

data = @{@"name": @"The Getty", @"type": @"museum"};
[[[citiesRef documentWithPath:@"LA"] collectionWithPath:@"landmarks"] addDocumentWithData:data];

data = @{@"name": @"Lincoln Memorial", @"type": @"memorial"};
[[[citiesRef documentWithPath:@"DC"] collectionWithPath:@"landmarks"] addDocumentWithData:data];

data = @{@"name": @"National Air and Space Museum", @"type": @"museum"};
[[[citiesRef documentWithPath:@"DC"] collectionWithPath:@"landmarks"] addDocumentWithData:data];

data = @{@"name": @"Ueno Park", @"type": @"park"};
[[[citiesRef documentWithPath:@"TOK"] collectionWithPath:@"landmarks"] addDocumentWithData:data];

data = @{@"name": @"National Museum of Nature and Science", @"type": @"museum"};
[[[citiesRef documentWithPath:@"TOK"] collectionWithPath:@"landmarks"] addDocumentWithData:data];

data = @{@"name": @"Jingshan Park", @"type": @"park"};
[[[citiesRef documentWithPath:@"BJ"] collectionWithPath:@"landmarks"] addDocumentWithData:data];

data = @{@"name": @"Beijing Ancient Observatory", @"type": @"museum"};
[[[citiesRef documentWithPath:@"BJ"] collectionWithPath:@"landmarks"] addDocumentWithData:data];
ViewController.m
Kotlin+KTX
Android
val citiesRef = db.collection("cities")

val ggbData = mapOf(
        "name" to "Golden Gate Bridge",
        "type" to "bridge"
)
citiesRef.document("SF").collection("landmarks").add(ggbData)

val lohData = mapOf(
        "name" to "Legion of Honor",
        "type" to "museum"
)
citiesRef.document("SF").collection("landmarks").add(lohData)

val gpData = mapOf(
        "name" to "Griffth Park",
        "type" to "park"
)
citiesRef.document("LA").collection("landmarks").add(gpData)

val tgData = mapOf(
        "name" to "The Getty",
        "type" to "museum"
)
citiesRef.document("LA").collection("landmarks").add(tgData)

val lmData = mapOf(
        "name" to "Lincoln Memorial",
        "type" to "memorial"
)
citiesRef.document("DC").collection("landmarks").add(lmData)

val nasaData = mapOf(
        "name" to "National Air and Space Museum",
        "type" to "museum"
)
citiesRef.document("DC").collection("landmarks").add(nasaData)

val upData = mapOf(
        "name" to "Ueno Park",
        "type" to "park"
)
citiesRef.document("TOK").collection("landmarks").add(upData)

val nmData = mapOf(
        "name" to "National Musuem of Nature and Science",
        "type" to "museum"
)
citiesRef.document("TOK").collection("landmarks").add(nmData)

val jpData = mapOf(
        "name" to "Jingshan Park",
        "type" to "park"
)
citiesRef.document("BJ").collection("landmarks").add(jpData)

val baoData = mapOf(
        "name" to "Beijing Ancient Observatory",
        "type" to "musuem"
)
citiesRef.document("BJ").collection("landmarks").add(baoData)
DocSnippets.kt
Java
Android
CollectionReference citiesRef = db.collection("cities");

Map<String, Object> ggbData = new HashMap<>();
ggbData.put("name", "Golden Gate Bridge");
ggbData.put("type", "bridge");
citiesRef.document("SF").collection("landmarks").add(ggbData);

Map<String, Object> lohData = new HashMap<>();
lohData.put("name", "Legion of Honor");
lohData.put("type", "museum");
citiesRef.document("SF").collection("landmarks").add(lohData);

Map<String, Object> gpData = new HashMap<>();
gpData.put("name", "Griffith Park");
gpData.put("type", "park");
citiesRef.document("LA").collection("landmarks").add(gpData);

Map<String, Object> tgData = new HashMap<>();
tgData.put("name", "The Getty");
tgData.put("type", "museum");
citiesRef.document("LA").collection("landmarks").add(tgData);

Map<String, Object> lmData = new HashMap<>();
lmData.put("name", "Lincoln Memorial");
lmData.put("type", "memorial");
citiesRef.document("DC").collection("landmarks").add(lmData);

Map<String, Object> nasaData = new HashMap<>();
nasaData.put("name", "National Air and Space Museum");
nasaData.put("type", "museum");
citiesRef.document("DC").collection("landmarks").add(nasaData);

Map<String, Object> upData = new HashMap<>();
upData.put("name", "Ueno Park");
upData.put("type", "park");
citiesRef.document("TOK").collection("landmarks").add(upData);

Map<String, Object> nmData = new HashMap<>();
nmData.put("name", "National Museum of Nature and Science");
nmData.put("type", "museum");
citiesRef.document("TOK").collection("landmarks").add(nmData);

Map<String, Object> jpData = new HashMap<>();
jpData.put("name", "Jingshan Park");
jpData.put("type", "park");
citiesRef.document("BJ").collection("landmarks").add(jpData);

Map<String, Object> baoData = new HashMap<>();
baoData.put("name", "Beijing Ancient Observatory");
baoData.put("type", "museum");
citiesRef.document("BJ").collection("landmarks").add(baoData);
DocSnippets.java

Dart

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

final ggbData = {"name": "Golden Gate Bridge", "type": "bridge"};
citiesRef.doc("SF").collection("landmarks").add(ggbData);

final lohData = {"name": "Legion of Honor", "type": "museum"};
citiesRef.doc("SF").collection("landmarks").add(lohData);

final gpData = {"name": "Griffth Park", "type": "park"};
citiesRef.doc("LA").collection("landmarks").add(gpData);

final tgData = {"name": "The Getty", "type": "museum"};
citiesRef.doc("LA").collection("landmarks").add(tgData);

final lmData = {"name": "Lincoln Memorial", "type": "memorial"};
citiesRef.doc("DC").collection("landmarks").add(lmData);

final nasaData = {
  "name": "National Air and Space Museum",
  "type": "museum"
};
citiesRef.doc("DC").collection("landmarks").add(nasaData);

final upData = {"name": "Ueno Park", "type": "park"};
citiesRef.doc("TOK").collection("landmarks").add(upData);

final nmData = {
  "name": "National Musuem of Nature and Science",
  "type": "museum"
};
citiesRef.doc("TOK").collection("landmarks").add(nmData);

final jpData = {"name": "Jingshan Park", "type": "park"};
citiesRef.doc("BJ").collection("landmarks").add(jpData);

final baoData = {"name": "Beijing Ancient Observatory", "type": "musuem"};
citiesRef.doc("BJ").collection("landmarks").add(baoData);
firestore.dart
Java
CollectionReference cities = db.collection("cities");

final List<ApiFuture<WriteResult>> futures =
    Arrays.asList(
        cities
            .document("SF")
            .collection("landmarks")
            .document()
            .set(
                new HashMap<String, String>() {
                  {
                    put("name", "Golden Gate Bridge");
                    put("type", "bridge");
                  }
                }),
        cities
            .document("SF")
            .collection("landmarks")
            .document()
            .set(
                new HashMap<String, String>() {
                  {
                    put("name", "Legion of Honor");
                    put("type", "museum");
                  }
                }),
        cities
            .document("LA")
            .collection("landmarks")
            .document()
            .set(
                new HashMap<String, String>() {
                  {
                    put("name", "Griffith Park");
                    put("type", "park");
                  }
                }),
        cities
            .document("LA")
            .collection("landmarks")
            .document()
            .set(
                new HashMap<String, String>() {
                  {
                    put("name", "The Getty");
                    put("type", "museum");
                  }
                }),
        cities
            .document("DC")
            .collection("landmarks")
            .document()
            .set(
                new HashMap<String, String>() {
                  {
                    put("name", "Lincoln Memorial");
                    put("type", "memorial");
                  }
                }),
        cities
            .document("DC")
            .collection("landmarks")
            .document()
            .set(
                new HashMap<String, String>() {
                  {
                    put("name", "National Air and Space Museum");
                    put("type", "museum");
                  }
                }),
        cities
            .document("TOK")
            .collection("landmarks")
            .document()
            .set(
                new HashMap<String, String>() {
                  {
                    put("name", "Ueno Park");
                    put("type", "park");
                  }
                }),
        cities
            .document("TOK")
            .collection("landmarks")
            .document()
            .set(
                new HashMap<String, String>() {
                  {
                    put("name", "National Museum of Nature and Science");
                    put("type", "museum");
                  }
                }),
        cities
            .document("BJ")
            .collection("landmarks")
            .document()
            .set(
                new HashMap<String, String>() {
                  {
                    put("name", "Jingshan Park");
                    put("type", "park");
                  }
                }),
        cities
            .document("BJ")
            .collection("landmarks")
            .document()
            .set(
                new HashMap<String, String>() {
                  {
                    put("name", "Beijing Ancient Observatory");
                    put("type", "museum");
                  }
                }));
final List<WriteResult> landmarks = ApiFutures.allAsList(futures).get();
QueryDataSnippets.java
Python
cities = db.collection(u'cities')

sf_landmarks = cities.document(u'SF').collection(u'landmarks')
sf_landmarks.document().set({
    u'name': u'Golden Gate Bridge',
    u'type': u'bridge'
})
sf_landmarks.document().set({
    u'name': u'Legion of Honor',
    u'type': u'museum'
})
la_landmarks = cities.document(u'LA').collection(u'landmarks')
la_landmarks.document().set({
    u'name': u'Griffith Park',
    u'type': u'park'
})
la_landmarks.document().set({
    u'name': u'The Getty',
    u'type': u'museum'
})
dc_landmarks = cities.document(u'DC').collection(u'landmarks')
dc_landmarks.document().set({
    u'name': u'Lincoln Memorial',
    u'type': u'memorial'
})
dc_landmarks.document().set({
    u'name': u'National Air and Space Museum',
    u'type': u'museum'
})
tok_landmarks = cities.document(u'TOK').collection(u'landmarks')
tok_landmarks.document().set({
    u'name': u'Ueno Park',
    u'type': u'park'
})
tok_landmarks.document().set({
    u'name': u'National Museum of Nature and Science',
    u'type': u'museum'
})
bj_landmarks = cities.document(u'BJ').collection(u'landmarks')
bj_landmarks.document().set({
    u'name': u'Jingshan Park',
    u'type': u'park'
})
bj_landmarks.document().set({
    u'name': u'Beijing Ancient Observatory',
    u'type': u'museum'
})
snippets.py
Python
(Async)
cities = db.collection("cities")

sf_landmarks = cities.document("SF").collection("landmarks")
await sf_landmarks.document().set({"name": "Golden Gate Bridge", "type": "bridge"})
await sf_landmarks.document().set({"name": "Legion of Honor", "type": "museum"})
la_landmarks = cities.document("LA").collection("landmarks")
await la_landmarks.document().set({"name": "Griffith Park", "type": "park"})
await la_landmarks.document().set({"name": "The Getty", "type": "museum"})
dc_landmarks = cities.document("DC").collection("landmarks")
await dc_landmarks.document().set({"name": "Lincoln Memorial", "type": "memorial"})
await dc_landmarks.document().set(
    {"name": "National Air and Space Museum", "type": "museum"}
)
tok_landmarks = cities.document("TOK").collection("landmarks")
await tok_landmarks.document().set({"name": "Ueno Park", "type": "park"})
await tok_landmarks.document().set(
    {"name": "National Museum of Nature and Science", "type": "museum"}
)
bj_landmarks = cities.document("BJ").collection("landmarks")
await bj_landmarks.document().set({"name": "Jingshan Park", "type": "park"})
await bj_landmarks.document().set(
    {"name": "Beijing Ancient Observatory", "type": "museum"}
)
snippets.py
C++
// This is not yet supported.
Node.js
const citiesRef = db.collection('cities');

await citiesRef.doc('SF').collection('landmarks').doc().set({
  name: 'Golden Gate Bridge',
  type: 'bridge'
});
await citiesRef.doc('SF').collection('landmarks').doc().set({
  name: 'Legion of Honor',
  type: 'museum'
});
await citiesRef.doc('LA').collection('landmarks').doc().set({
  name: 'Griffith Park',
  type: 'park'
});
await citiesRef.doc('LA').collection('landmarks').doc().set({
  name: 'The Getty',
  type: 'museum'
});
await citiesRef.doc('DC').collection('landmarks').doc().set({
  name: 'Lincoln Memorial',
  type: 'memorial'
});
await citiesRef.doc('DC').collection('landmarks').doc().set({
  name: 'National Air and Space Museum',
  type: 'museum'
});
await citiesRef.doc('TOK').collection('landmarks').doc().set({
  name: 'Ueno Park',
  type: 'park'
});
await citiesRef.doc('TOK').collection('landmarks').doc().set({
  name: 'National Museum of Nature and Science',
  type: 'museum'
});
await citiesRef.doc('BJ').collection('landmarks').doc().set({
  name: 'Jingshan Park',
  type: 'park'
});
await citiesRef.doc('BJ').collection('landmarks').doc().set({
  name: 'Beijing Ancient Observatory',
  type: 'museum'
});
index.js
Einfach loslegen (Go)
import (
	"context"
	"fmt"

	"cloud.google.com/go/firestore"
)

// collectionGroupSetup sets up a collection group to query.
func collectionGroupSetup(projectID, cityCollection string) error {
	ctx := context.Background()

	client, err := firestore.NewClient(ctx, projectID)
	if err != nil {
		return fmt.Errorf("firestore.NewClient: %v", err)
	}
	defer client.Close()

	landmarks := []struct {
		city, name, t string
	}{
		{"SF", "Golden Gate Bridge", "bridge"},
		{"SF", "Legion of Honor", "museum"},
		{"LA", "Griffith Park", "park"},
		{"LA", "The Getty", "museum"},
		{"DC", "Lincoln Memorial", "memorial"},
		{"DC", "National Air and Space Museum", "museum"},
		{"TOK", "Ueno Park", "park"},
		{"TOK", "National Museum of Nature and Science", "museum"},
		{"BJ", "Jingshan Park", "park"},
		{"BJ", "Beijing Ancient Observatory", "museum"},
	}

	cities := client.Collection(cityCollection)
	for _, l := range landmarks {
		if _, err := cities.Doc(l.city).Collection("landmarks").NewDoc().Set(ctx, map[string]string{
			"name": l.name,
			"type": l.t,
		}); err != nil {
			return fmt.Errorf("Set: %v", err)
		}
	}

	return nil
}

collection_group_setup.go
PHP
$citiesRef = $db->collection('samples/php/cities');
$citiesRef->document('SF')->collection('landmarks')->newDocument()->set([
    'name' => 'Golden Gate Bridge',
    'type' => 'bridge'
]);
$citiesRef->document('SF')->collection('landmarks')->newDocument()->set([
    'name' => 'Legion of Honor',
    'type' => 'museum'
]);
$citiesRef->document('LA')->collection('landmarks')->newDocument()->set([
    'name' => 'Griffith Park',
    'type' => 'park'
]);
$citiesRef->document('LA')->collection('landmarks')->newDocument()->set([
    'name' => 'The Getty',
    'type' => 'museum'
]);
$citiesRef->document('DC')->collection('landmarks')->newDocument()->set([
    'name' => 'Lincoln Memorial',
    'type' => 'memorial'
]);
$citiesRef->document('DC')->collection('landmarks')->newDocument()->set([
    'name' => 'National Air and Space Museum',
    'type' => 'museum'
]);
$citiesRef->document('TOK')->collection('landmarks')->newDocument()->set([
    'name' => 'Ueno Park',
    'type' => 'park'
]);
$citiesRef->document('TOK')->collection('landmarks')->newDocument()->set([
    'name' => 'National Museum of Nature and Science',
    'type' => 'museum'
]);
$citiesRef->document('BJ')->collection('landmarks')->newDocument()->set([
    'name' => 'Jingshan Park',
    'type' => 'park'
]);
$citiesRef->document('BJ')->collection('landmarks')->newDocument()->set([
    'name' => 'Beijing Ancient Observatory',
    'type' => 'museum'
]);
print('Added example landmarks collections to the cities collection.' . PHP_EOL);
query_collection_group_dataset.php
Unity
// Not yet supported in the Unity SDK
C#
// Copyright(c) 2017 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not
// use this file except in compliance with the License. You may obtain a copy of
// the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations under
// the License.

using Google.Cloud.Firestore;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Threading.Tasks;

namespace GoogleCloudSamples
{
    public class QueryData
    {
        public static string Usage = @"Usage:
C:\> dotnet run command YOUR_PROJECT_ID

Where command is one of
    query-create-examples
    create-query-state
    create-query-capital
    simple-queries
    array-contains-query
    array-contains-any-query
    in-query
    in-query-array
    collection-group-query
    chained-query
    composite-index-chained-query
    range-query
    invalid-range-query
";
        private static async Task QueryCreateExamples(string project)
        {
            FirestoreDb db = FirestoreDb.Create(project);
            CollectionReference citiesRef = db.Collection("cities");
            await citiesRef.Document("SF").SetAsync(new Dictionary<string, object>(){
                { "Name", "San Francisco" },
                { "State", "CA" },
                { "Country", "USA" },
                { "Capital", false },
                { "Population", 860000 },
                { "Regions", new ArrayList{"west_coast", "norcal"} }
            });
            await citiesRef.Document("LA").SetAsync(new Dictionary<string, object>(){
                { "Name", "Los Angeles" },
                { "State", "CA" },
                { "Country", "USA" },
                { "Capital", false },
                { "Population", 3900000 },
                { "Regions", new ArrayList{"west_coast", "socal"} }
            });
            await citiesRef.Document("DC").SetAsync(new Dictionary<string, object>(){
                { "Name", "Washington D.C." },
                { "State", null },
                { "Country", "USA" },
                { "Capital", true },
                { "Population", 680000 },
                { "Regions", new ArrayList{"east_coast"} }
            });
            await citiesRef.Document("TOK").SetAsync(new Dictionary<string, object>(){
                { "Name", "Tokyo" },
                { "State", null },
                { "Country", "Japan" },
                { "Capital", true },
                { "Population", 9000000 },
                { "Regions", new ArrayList{"kanto", "honshu"} }
            });
            await citiesRef.Document("BJ").SetAsync(new Dictionary<string, object>(){
                { "Name", "Beijing" },
                { "State", null },
                { "Country", "China" },
                { "Capital", true },
                { "Population", 21500000 },
                { "Regions", new ArrayList{"jingjinji", "hebei"} }
            });
            Console.WriteLine("Added example cities data to the cities collection.");
        }

        private static async Task CreateQueryState(string project)
        {
            FirestoreDb db = FirestoreDb.Create(project);
            CollectionReference citiesRef = db.Collection("cities");
            Query query = citiesRef.WhereEqualTo("State", "CA");
            QuerySnapshot querySnapshot = await query.GetSnapshotAsync();
            foreach (DocumentSnapshot documentSnapshot in querySnapshot.Documents)
            {
                Console.WriteLine("Document {0} returned by query State=CA", documentSnapshot.Id);
            }
        }

        private static async Task CreateQueryCapital(string project)
        {
            FirestoreDb db = FirestoreDb.Create(project);
            CollectionReference citiesRef = db.Collection("cities");
            Query query = citiesRef.WhereEqualTo("Capital", true);
            QuerySnapshot querySnapshot = await query.GetSnapshotAsync();
            foreach (DocumentSnapshot documentSnapshot in querySnapshot.Documents)
            {
                Console.WriteLine("Document {0} returned by query Capital=true", documentSnapshot.Id);
            }
        }

        private static async Task SimpleQueries(string project)
        {
            FirestoreDb db = FirestoreDb.Create(project);
            CollectionReference citiesRef = db.Collection("cities");
            Query stateQuery = citiesRef.WhereEqualTo("State", "CA");
            Query populationQuery = citiesRef.WhereGreaterThan("Population", 1000000);
            Query nameQuery = citiesRef.WhereGreaterThanOrEqualTo("Name", "San Francisco");
            QuerySnapshot stateQuerySnapshot = await stateQuery.GetSnapshotAsync();
            foreach (DocumentSnapshot documentSnapshot in stateQuerySnapshot.Documents)
            {
                Console.WriteLine("Document {0} returned by query State=CA", documentSnapshot.Id);
            }
            QuerySnapshot populationQuerySnapshot = await populationQuery.GetSnapshotAsync();
            foreach (DocumentSnapshot documentSnapshot in populationQuerySnapshot.Documents)
            {
                Console.WriteLine("Document {0} returned by query Population>1000000", documentSnapshot.Id);
            }
            QuerySnapshot nameQuerySnapshot = await nameQuery.GetSnapshotAsync();
            foreach (DocumentSnapshot documentSnapshot in nameQuerySnapshot.Documents)
            {
                Console.WriteLine("Document {0} returned by query Name>=San Francisco", documentSnapshot.Id);
            }
        }

        private static async Task ArrayContainsQuery(string project)
        {
            FirestoreDb db = FirestoreDb.Create(project);
            CollectionReference citiesRef = db.Collection("cities");
            Query query = citiesRef.WhereArrayContains("Regions", "west_coast");
            QuerySnapshot querySnapshot = await query.GetSnapshotAsync();
            foreach (DocumentSnapshot documentSnapshot in querySnapshot.Documents)
            {
                Console.WriteLine("Document {0} returned by query 'Regions array_contains west_coast'", documentSnapshot.Id);
            }
        }

        private static async Task ArrayContainsAnyQuery(string project)
        {
            FirestoreDb db = FirestoreDb.Create(project);
            CollectionReference citiesRef = db.Collection("cities");
            Query query = citiesRef.WhereArrayContainsAny("Regions", new[] { "west_coast", "east_coast" });
            QuerySnapshot querySnapshot = await query.GetSnapshotAsync();
            foreach (DocumentSnapshot documentSnapshot in querySnapshot.Documents)
            {
                Console.WriteLine("Document {0} returned by query 'Regions array_contains_any {{west_coast, east_coast}}'", documentSnapshot.Id);
            }
        }

        private static async Task InQueryWithoutArray(string project)
        {
            FirestoreDb db = FirestoreDb.Create(project);
            CollectionReference citiesRef = db.Collection("cities");
            Query query = citiesRef.WhereIn("Country", new[] { "USA", "Japan" });
            QuerySnapshot querySnapshot = await query.GetSnapshotAsync();
            foreach (DocumentSnapshot documentSnapshot in querySnapshot.Documents)
            {
                Console.WriteLine("Document {0} returned by query 'Country in {{USA, Japan}}'", documentSnapshot.Id);
            }
        }

        private static async Task InQueryWithArray(string project)
        {
            FirestoreDb db = FirestoreDb.Create(project);
            CollectionReference citiesRef = db.Collection("cities");
            Query query = citiesRef.WhereIn("Regions",
                new[] { new[] { "west_coast" }, new[] { "east_coast" } });
            QuerySnapshot querySnapshot = await query.GetSnapshotAsync();
            foreach (DocumentSnapshot documentSnapshot in querySnapshot.Documents)
            {
                Console.WriteLine("Document {0} returned by query 'Regions in {{west_coast}}, {{east_coast}}'", documentSnapshot.Id);
            }
        }

        private static async Task CollectionGroupQuery(string project)
        {
            FirestoreDb db = FirestoreDb.Create(project);
            CollectionReference citiesRef = db.Collection("cities");
            await citiesRef.Document("SF").Collection("landmarks").Document()
                .CreateAsync(new { Name = "Golden Gate Bridge", Type = "bridge" });
            await citiesRef.Document("SF").Collection("landmarks").Document()
                .CreateAsync(new { Name = "Legion of Honor", Type = "museum" });
            await citiesRef.Document("LA").Collection("landmarks").Document()
                .CreateAsync(new { Name = "Griffith Park", Type = "park" });
            await citiesRef.Document("DC").Collection("landmarks").Document()
                .CreateAsync(new { Name = "Lincoln Memorial", Type = "memorial" });
            await citiesRef.Document("DC").Collection("landmarks").Document()
                .CreateAsync(new { Name = "National Air And Space Museum", Type = "museum" });
            await citiesRef.Document("TOK").Collection("landmarks").Document()
                .CreateAsync(new { Name = "Ueno Park", Type = "park" });
            await citiesRef.Document("TOK").Collection("landmarks").Document()
                .CreateAsync(new { Name = "National Museum of Nature and Science", Type = "museum" });
            await citiesRef.Document("BJ").Collection("landmarks").Document()
                .CreateAsync(new { Name = "Jingshan Park", Type = "park" });
            await citiesRef.Document("BJ").Collection("landmarks").Document()
                .CreateAsync(new { Name = "Beijing Ancient Observatory", Type = "museum" });

            Query museums = db.CollectionGroup("landmarks").WhereEqualTo("Type", "museum");
            QuerySnapshot querySnapshot = await museums.GetSnapshotAsync();
            foreach (DocumentSnapshot document in querySnapshot.Documents)
            {
                Console.WriteLine($"{document.Reference.Path}: {document.GetValue<string>("Name")}");
            }
        }

        private static async Task ChainedQuery(string project)
        {
            FirestoreDb db = FirestoreDb.Create(project);
            CollectionReference citiesRef = db.Collection("cities");
            Query chainedQuery = citiesRef
                .WhereEqualTo("State", "CA")
                .WhereEqualTo("Name", "San Francisco");
            QuerySnapshot querySnapshot = await chainedQuery.GetSnapshotAsync();
            foreach (DocumentSnapshot documentSnapshot in querySnapshot.Documents)
            {
                Console.WriteLine("Document {0} returned by query State=CA and Name=San Francisco", documentSnapshot.Id);
            }
        }

        private static async Task CompositeIndexChainedQuery(string project)
        {
            FirestoreDb db = FirestoreDb.Create(project);
            CollectionReference citiesRef = db.Collection("cities");
            Query chainedQuery = citiesRef
                .WhereEqualTo("State", "CA")
                .WhereLessThan("Population", 1000000);
            QuerySnapshot querySnapshot = await chainedQuery.GetSnapshotAsync();
            foreach (DocumentSnapshot documentSnapshot in querySnapshot.Documents)
            {
                Console.WriteLine("Document {0} returned by query State=CA and Population<1000000", documentSnapshot.Id);
            }