Esegui query semplici e composte in Cloud Firestore

Cloud Firestore fornisce potenti funzionalità di query per specificare quali documenti desideri recuperare da una raccolta o da un gruppo di raccolte. Queste query possono essere utilizzate anche con get() o addSnapshotListener() , come descritto in Ottenere dati e ottenere aggiornamenti in tempo reale .

Dati di esempio

Per iniziare, scrivi alcuni dati sulle città in modo da poter esaminare diversi modi per rileggerli:

Web modular API

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

Web namespaced API

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
Veloce
Nota: questo prodotto non è disponibile sui target watchOS e App Clip.
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
Obiettivo-C
Nota: questo prodotto non è disponibile sui target watchOS e App Clip.
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

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

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
Giava
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
Pitone
class City:
    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")
cities_ref.document("BJ").set(
    City("Beijing", None, "China", True, 21500000, ["hebei"]).to_dict()
)
cities_ref.document("SF").set(
    City(
        "San Francisco", "CA", "USA", False, 860000, ["west_coast", "norcal"]
    ).to_dict()
)
cities_ref.document("LA").set(
    City(
        "Los Angeles", "CA", "USA", False, 3900000, ["west_coast", "socal"]
    ).to_dict()
)
cities_ref.document("DC").set(
    City("Washington D.C.", None, "USA", True, 680000, ["east_coast"]).to_dict()
)
cities_ref.document("TOK").set(
    City("Tokyo", None, "Japan", True, 9000000, ["kanto", "honshu"]).to_dict()
)
snippets.py

Python

class City:
    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
Andare
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
Unità
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
Rubino
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

Domande semplici

La seguente query restituisce tutte le città con CA dello stato:

Web modular API

// 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

Web namespaced API

// 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
Veloce
Nota: questo prodotto non è disponibile sui target watchOS e App Clip.
// 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
Obiettivo-C
Nota: questo prodotto non è disponibile sui target watchOS e App Clip.
// 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

// 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

// 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
Giava
// 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
Pitone
# Create a reference to the cities collection
cities_ref = db.collection("cities")

# Create a query against the collection
query_ref = cities_ref.where(filter=FieldFilter("state", "==", "CA"))
snippets.py

Python

# Create a reference to the cities collection
cities_ref = db.collection("cities")

# Create a query against the collection
query_ref = cities_ref.where(filter=FieldFilter("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
Andare
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
Unità
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
Rubino
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

La seguente query restituisce tutte le capitali:

Web modular API

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

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

Web namespaced API

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

var query = citiesRef.where("capital", "==", true);
test.firestore.js
Veloce
Nota: questo prodotto non è disponibile sui target watchOS e App Clip.
let capitalCities = db.collection("cities").whereField("capital", isEqualTo: true)
ViewController.swift
Obiettivo-C
Nota: questo prodotto non è disponibile sui target watchOS e App Clip.
FIRQuery *capitalCities =
    [[self.db collectionWithPath:@"cities"] queryWhereField:@"capital" isEqualTo:@YES];
ViewController.m

Kotlin+KTX

val capitalCities = db.collection("cities").whereEqualTo("capital", true)
DocSnippets.kt

Java

Query capitalCities = db.collection("cities").whereEqualTo("capital", true);
DocSnippets.java

Dart

final capitalcities =
    db.collection("cities").where("capital", isEqualTo: true);
firestore.dart
Giava
// 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
Pitone
cities_ref = db.collection("cities")

query = cities_ref.where(filter=FieldFilter("capital", "==", True))
snippets.py

Python

cities_ref = db.collection("cities")

query = cities_ref.where(filter=FieldFilter("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 = citiesRef.where('capital', '==', true);
index.js
Andare
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
Unità
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
Rubino
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

Esegui una query

Dopo aver creato un oggetto query, utilizza la funzione get() per recuperare i risultati:

Web modular API

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

Web namespaced API

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
Veloce
Nota: questo prodotto non è disponibile sui target watchOS e App Clip.
do {
  let querySnapshot = try await db.collection("cities").whereField("capital", isEqualTo: true)
    .getDocuments()
  for document in querySnapshot.documents {
    print("\(document.documentID) => \(document.data())")
  }
} catch {
  print("Error getting documents: \(error)")
}
ViewController.swift
Obiettivo-C
Nota: questo prodotto non è disponibile sui target watchOS e App Clip.
[[[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

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

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(
  (querySnapshot) {
    print("Successfully completed");
    for (var docSnapshot in querySnapshot.docs) {
      print('${docSnapshot.id} => ${docSnapshot.data()}');
    }
  },
  onError: (e) => print("Error completing: $e"),
);
firestore.dart
Giava
// 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
Pitone
# Note: Use of CollectionRef stream() is prefered to get()
docs = (
    db.collection("cities")
    .where(filter=FieldFilter("capital", "==", True))
    .stream()
)

for doc in docs:
    print(f"{doc.id} => {doc.to_dict()}")
snippets.py

Python

# Note: Use of CollectionRef stream() is prefered to get()
docs = (
    db.collection("cities")
    .where(filter=FieldFilter("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
Andare

import (
	"context"
	"fmt"

	"cloud.google.com/go/firestore"
	"google.golang.org/api/iterator"
)

func multipleDocs(ctx context.Context, client *firestore.Client) error {
	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())
	}
	return nil
}

retrieve_data_query.go
PHP

PHP

Per ulteriori informazioni sull'installazione e sulla creazione di un client Cloud Firestore, fare riferimento a Librerie client Cloud Firestore .

$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());
    }
}
data_query.php
Unità
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
Rubino
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

Vedi Ottieni dati per ulteriori informazioni sul recupero dei risultati della query. Puoi anche aggiungere un ascoltatore a una query per ottenere i risultati correnti e ascoltare gli aggiornamenti futuri.

Operatori di interrogazione

Il metodo where() accetta tre parametri: un campo su cui filtrare, un operatore di confronto e un valore. Cloud Firestore supporta i seguenti operatori di confronto:

Per esempio:

Web modular API

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

Web namespaced API

const stateQuery = citiesRef.where("state", "==", "CA");
const populationQuery = citiesRef.where("population", "<", 100000);
const nameQuery = citiesRef.where("name", ">=", "San Francisco");
test.firestore.js
Veloce
Nota: questo prodotto non è disponibile sui target watchOS e App Clip.
let stateQuery = citiesRef.whereField("state", isEqualTo: "CA")
let populationQuery = citiesRef.whereField("population", isLessThan: 100000)
let nameQuery = citiesRef.whereField("name", isGreaterThanOrEqualTo: "San Francisco")
ViewController.swift
Obiettivo-C
Nota: questo prodotto non è disponibile sui target watchOS e App Clip.
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

val stateQuery = citiesRef.whereEqualTo("state", "CA")
val populationQuery = citiesRef.whereLessThan("population", 100000)
val nameQuery = citiesRef.whereGreaterThanOrEqualTo("name", "San Francisco")
DocSnippets.kt

Java

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
Giava
Query stateQuery = cities.whereEqualTo("state", "CA");
Query populationQuery = cities.whereLessThan("population", 1000000L);
Query nameQuery = cities.whereGreaterThanOrEqualTo("name", "San Francisco");
QueryDataSnippets.java
Pitone
cities_ref = db.collection("cities")

cities_ref.where(filter=FieldFilter("state", "==", "CA"))
cities_ref.where(filter=FieldFilter("population", "<", 1000000))
cities_ref.where(filter=FieldFilter("name", ">=", "San Francisco"))
snippets.py

Python

cities_ref = db.collection("cities")

cities_ref.where(filter=FieldFilter("state", "==", "CA"))
cities_ref.where(filter=FieldFilter("population", "<", 1000000))
cities_ref.where(filter=FieldFilter("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
Andare
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
Unità
Query stateQuery = citiesRef.WhereEqualTo("State", "CA");
Query populationQuery = citiesRef.WhereGreaterThan("Population", 1000000);
Query nameQuery = citiesRef.WhereGreaterThanOrEqualTo("Name", "San Francisco");
C#
CollectionReference citiesRef = db.Collection("cities");
Query stateQuery = citiesRef.WhereEqualTo("State", "CA");
Query populationQuery = citiesRef.WhereGreaterThan("Population", 1000000);
Query nameQuery = citiesRef.WhereGreaterThanOrEqualTo("Name", "San Francisco");
Program.cs
Rubino
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

Non uguale ( != )

Utilizzare l'operatore diverso ( != ) per restituire documenti in cui il campo specificato esiste e non corrisponde al valore di confronto. Per esempio:

Web modular API

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

Web namespaced API

citiesRef.where("capital", "!=", false);
test.firestore.js
Veloce
Nota: questo prodotto non è disponibile sui target watchOS e App Clip.
let notEqualQuery = citiesRef.whereField("capital", isNotEqualTo: false)
ViewController.swift
Obiettivo-C
Nota: questo prodotto non è disponibile sui target watchOS e App Clip.
query = [citiesRef queryWhereField:@"capital" isNotEqualTo:@NO];
ViewController.m

Kotlin+KTX

val notCapitalQuery = citiesRef.whereNotEqualTo("capital", false)
DocSnippets.kt

Java

Query notCapitalQuery = citiesRef.whereNotEqualTo("capital", false);
DocSnippets.java

Dart

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

Query query = citiesRef.whereNotEqualTo("capital", false);
QueryDataSnippets.java
Pitone
// Snippet not yet available
C++
cities_ref.WhereNotEqualTo("capital", FieldValue::Boolean(false));
Node.js
const capitalNotFalseRes = await citiesRef.where('capital', '!=', false).get();
index.js
Andare
// Snippet not yet available
PHP
$stateQuery = $citiesRef->where('capital', '!=', false);
query_filter_not_eq.php
Unità
Query query = citiesRef.WhereNotEqualTo("capital", false);
Query query = citiesRef.WhereNotEqualTo("capital", false);
C#
// Snippet not yet available
Rubino
cities_ref = firestore.col collection_path
query = cities_ref.where "capital", "!=", false
query_data.rb

Questa query restituisce ogni documento city in cui esiste il campo capital con un valore diverso da false o null . Ciò include i documenti city in cui il valore del campo capital è uguale true o qualsiasi valore non booleano oltre null .

Questa query non restituisce documenti city in cui il campo capital non esiste. Le query non uguali ( != ) e not-in escludono i documenti in cui il campo specificato non esiste .

Un campo esiste quando è impostato su qualsiasi valore, inclusa una stringa vuota ( "" ), null e NaN (non un numero). Tieni presente che i valori del campo null non corrispondono alle clausole != , perché x != null restituisce undefined .

Limitazioni

Tieni presenti le seguenti limitazioni per le query != :

  • Solo i documenti in cui esiste il campo specificato possono corrispondere alla query.
  • Non è possibile combinare not-in e != in una query composta.
  • In una query composta, i confronti tra intervalli ( < , <= , > , >= ) e diversi da ( != , not-in ) devono essere tutti filtrati sullo stesso campo.

Appartenenza all'array

È possibile utilizzare l'operatore array-contains per filtrare in base ai valori dell'array. Per esempio:

Web modular API

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

Web namespaced API

citiesRef.where("regions", "array-contains", "west_coast");
test.firestore.js
Veloce
Nota: questo prodotto non è disponibile sui target watchOS e App Clip.
citiesRef
  .whereField("regions", arrayContains: "west_coast")
ViewController.swift
Obiettivo-C
Nota: questo prodotto non è disponibile sui target watchOS e App Clip.
[citiesRef queryWhereField:@"state" arrayContains:@"west_coast"];
ViewController.m

Kotlin+KTX

val citiesRef = db.collection("cities")

citiesRef.whereArrayContains("regions", "west_coast")
DocSnippets.kt

Java

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
Giava
CollectionReference citiesRef = db.collection("cities");
Query westCoastQuery = citiesRef.whereArrayContains("regions", "west_coast");
QueryDataSnippets.java
Pitone
cities_ref = db.collection("cities")

query = cities_ref.where(
    filter=FieldFilter("regions", "array_contains", "west_coast")
)
snippets.py

Python

cities_ref = db.collection("cities")

query = cities_ref.where(
    filter=FieldFilter("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
Andare
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
Unità
CollectionReference citiesRef = db.Collection("cities");
Query arrayContainsQuery = citiesRef.WhereArrayContains("region", "west_coast");
C#
CollectionReference citiesRef = db.Collection("cities");
Query query = citiesRef.WhereArrayContains("Regions", "west_coast");
Program.cs
Rubino
cities_ref = firestore.col collection_path
cities = cities_ref.where "regions", "array-contains", "west_coast"
query_data.rb

Questa query restituisce ogni documento city in cui il campo regions è un array che contiene west_coast . Se l'array contiene più istanze del valore su cui si esegue la query, il documento viene incluso nei risultati solo una volta.

È possibile utilizzare al massimo una clausola array-contains per disgiunzione ( or gruppo). Non è possibile combinare array-contains con array-contains-any nella stessa disgiunzione.

in , not-in e array-contains-any

Utilizza l'operatore in per combinare fino a 30 clausole di uguaglianza ( == ) sullo stesso campo con un OR logico. Una in restituisce documenti in cui il campo specificato corrisponde a uno qualsiasi dei valori di confronto. Per esempio:

Web modular API

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

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

Web namespaced API

citiesRef.where('country', 'in', ['USA', 'Japan']);
test.firestore.js
Veloce
Nota: questo prodotto non è disponibile sui target watchOS e App Clip.
let citiesRef = db.collection("cities")

citiesRef.whereField("country", in: ["USA", "Japan"])
ViewController.swift
Obiettivo-C
Nota: questo prodotto non è disponibile sui target watchOS e App Clip.
FIRCollectionReference *citiesRef = [self.db collectionWithPath:@"cities"];

[citiesRef queryWhereField:@"country" in:@[@"USA", @"Japan"]];
ViewController.m

Kotlin+KTX

val citiesRef = db.collection("cities")

citiesRef.whereIn("country", listOf("USA", "Japan"))
DocSnippets.kt

Java

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
Giava
CollectionReference citiesRef = db.collection("cities");

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

query = cities_ref.where(filter=FieldFilter("country", "in", ["USA", "Japan"]))
return query
snippets.py

Python

cities_ref = db.collection("cities")

query = cities_ref.where(filter=FieldFilter("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
Andare
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
Unità
CollectionReference citiesRef = db.Collection("cities");
List countriesList = new List<object>() {"USA", "Japan"};

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

Questa query restituisce ogni documento city in cui il campo country è impostato su USA o Japan . Dai dati di esempio, ciò include i documenti SF , LA , DC e TOK .

not-in

Utilizza l'operatore not-in per combinare fino a 10 clausole non uguali ( != ) nello stesso campo con un AND logico. Una query not-in restituisce documenti in cui esiste il campo specificato, non è null e non corrisponde a nessuno dei valori di confronto. Per esempio:

Web modular API

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

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

Web namespaced API

citiesRef.where('country', 'not-in', ['USA', 'Japan']);
test.firestore.js
Veloce
Nota: questo prodotto non è disponibile sui target watchOS e App Clip.
citiesRef.whereField("country", notIn: ["USA", "Japan"])
ViewController.swift
Obiettivo-C
Nota: questo prodotto non è disponibile sui target watchOS e App Clip.
[citiesRef queryWhereField:@"country" notIn:@[@"USA", @"Japan"]];
ViewController.m

Kotlin+KTX

citiesRef.whereNotIn("country", listOf("USA", "Japan"))
DocSnippets.kt

Java

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
Giava
CollectionReference citiesRef = db.collection("cities");

Query query = citiesRef.whereNotIn("country", Arrays.asList("USA", "Japan"));
QueryDataSnippets.java
Pitone
// 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
Andare
// 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
Unità
Query query = citiesRef.WhereNotIn(new FieldPath("country"), new List<string>{"USA", "Japan"});
Query query = citiesRef.WhereNotIn("country", new List<object>(){"USA", "Japan"});
C#
// Snippet not yet available
Rubino
cities_ref = firestore.col collection_path
usr_or_japan = cities_ref.where "country", "not_in", ["USA", "Japan"]
query_data.rb

Questa query restituisce ogni documento city in cui esiste il campo country e non è impostato su USA , Japan o null . Dai dati di esempio, ciò include i documenti London e Hong Kong .

Le query not-in escludono i documenti in cui il campo specificato non esiste. Un campo esiste quando è impostato su qualsiasi valore, inclusa una stringa vuota ( "" ), null e NaN (non un numero). Tieni presente che x != null restituisce undefined . Una query not-in con null come uno dei valori di confronto non corrisponde ad alcun documento.

array-contains-any

Utilizza l'operatore array-contains-any per combinare fino a 30 array-contains sullo stesso campo con un OR logico. Una array-contains-any restituisce documenti in cui il campo specificato è un array che contiene uno o più valori di confronto:

Web modular API

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

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

Web namespaced API

citiesRef.where('regions', 'array-contains-any',
    ['west_coast', 'east_coast']);
test.firestore.js
Veloce
Nota: questo prodotto non è disponibile sui target watchOS e App Clip.
let citiesRef = db.collection("cities")
citiesRef.whereField("regions", arrayContainsAny: ["west_coast", "east_coast"])
ViewController.swift
Obiettivo-C
Nota: questo prodotto non è disponibile sui target watchOS e App Clip.
FIRCollectionReference *citiesRef = [self.db collectionWithPath:@"cities"];

[citiesRef queryWhereField:@"regions" arrayContainsAny:@[@"west_coast", @"east_coast"]];
ViewController.m

Kotlin+KTX

val citiesRef = db.collection("cities")

citiesRef.whereArrayContainsAny("regions", listOf("west_coast", "east_coast"))
DocSnippets.kt

Java

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
Giava
CollectionReference citiesRef = db.collection("cities");

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

query = cities_ref.where(
    filter=FieldFilter(
        "regions", "array_contains_any", ["west_coast", "east_coast"]
    )
)
return query
snippets.py

Python

cities_ref = db.collection("cities")

query = cities_ref.where(
    filter=FieldFilter(
        "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
Andare
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
Unità
Query query = citiesRef.WhereArrayContainsAny(
                         "regions",
                         new List<object>()
                         {
                            new List<object>(){"west_coast"},
                            new List<object>(){"east_coast"}});
C#
CollectionReference citiesRef = db.Collection("cities");
Query query = citiesRef.WhereArrayContainsAny("Regions", new[] { "west_coast", "east_coast" });
Program.cs
Rubino
cities_ref = firestore.col collection_path
costal_cities = cities_ref.where "regions", "array-contains-any", ["west_coast", "east_coast"]
query_data.rb

Questa query restituisce ogni documento di città in cui il campo regions è un array che contiene west_coast o east_coast . Dai dati di esempio, ciò include i documenti SF , LA e DC .

I risultati di array-contains-any vengono deduplicati. Anche se il campo dell'array di un documento corrisponde a più di uno dei valori di confronto, il set di risultati include quel documento solo una volta.

array-contains-any filtra sempre in base al tipo di dati dell'array. Ad esempio, la query precedente non restituirebbe un documento di città in cui invece di un array, il campo regions è la stringa west_coast .

È possibile utilizzare un valore di array come valore di confronto per in , ma a differenza di array-contains-any , la clausola corrisponde a una corrispondenza esatta di lunghezza, ordine e valori dell'array. Per esempio:

Web modular API

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

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

Web namespaced API

citiesRef.where('regions', 'in',
    [['west_coast'], ['east_coast']]);
test.firestore.js
Veloce
Nota: questo prodotto non è disponibile sui target watchOS e App Clip.
citiesRef.whereField("regions", in: [["west_coast"], ["east_coast"]])
ViewController.swift
Obiettivo-C
Nota: questo prodotto non è disponibile sui target watchOS e App Clip.
[citiesRef queryWhereField:@"regions" in:@[@[@"west_coast"], @[@"east_coast"]]];
ViewController.m

Kotlin+KTX

citiesRef.whereIn("regions", listOf(arrayOf("west_coast"), arrayOf("east_coast")))
DocSnippets.kt

Java

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
Giava
CollectionReference citiesRef = db.collection("cities");

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

query = cities_ref.where(
    filter=FieldFilter("regions", "in", [["west_coast"], ["east_coast"]])
)
return query
snippets.py

Python

cities_ref = db.collection("cities")

query = cities_ref.where(
    filter=FieldFilter("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
Andare
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
Unità
Query query = citiesRef.WhereIn(new FieldPath("regions"), new List<string>{"west_coast", "east_coast"});
C#
CollectionReference citiesRef = db.Collection("cities");
Query query = citiesRef.WhereIn("Regions",
    new[] { new[] { "west_coast" }, new[] { "east_coast" } });
Program.cs
Rubino
cities_ref = firestore.col collection_path
exactly_one_cost = cities_ref.where "regions", "in", [["west_coast"], ["east_coast"]]
query_data.rb

Questa query restituisce ogni documento di città in cui il campo regions è un array che contiene esattamente un elemento di west_coast o east_coast . Dai dati di esempio, solo il documento DC si qualifica con il campo delle regions di ["east_coast"] . Il documento SF , tuttavia, non corrisponde perché il campo delle regions è ["west_coast", "norcal"] .

Limitazioni

Tieni presenti le seguenti limitazioni per in , not-in e array-contains-any :

  • Cloud Firestore fornisce supporto per query OR logiche tramite gli operatori or , in e array-contains-any . Queste query sono limitate a 30 disgiunzioni basate sulla forma normale disgiuntiva della query .
  • È possibile utilizzare al massimo una clausola array-contains per disgiunzione ( or gruppo). Non è possibile combinare array-contains con array-contains-any nella stessa disgiunzione.
  • Non è possibile combinare not-in con not equals != .
  • not-in supporta fino a 10 valori di confronto.

Query composte ( AND ).

È possibile combinare i vincoli con un AND logico concatenando più operatori di uguaglianza ( == o array-contains ). Tuttavia, è necessario creare un indice composito per combinare gli operatori di uguaglianza con gli operatori di disuguaglianza < , <= , > e != .

Web modular API

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

Web namespaced API

const q1 = citiesRef.where("state", "==", "CO").where("name", "==", "Denver");
const q2 = citiesRef.where("state", "==", "CA").where("population", "<", 1000000);
test.firestore.js
Veloce
Nota: questo prodotto non è disponibile sui target watchOS e App Clip.
citiesRef
  .whereField("state", isEqualTo: "CO")
  .whereField("name", isEqualTo: "Denver")
citiesRef
  .whereField("state", isEqualTo: "CA")
  .whereField("population", isLessThan: 1000000)
ViewController.swift
Obiettivo-C
Nota: questo prodotto non è disponibile sui target watchOS e App Clip.
[[citiesRef queryWhereField:@"state" isEqualTo:@"CO"]
    queryWhereField:@"name" isGreaterThanOrEqualTo:@"Denver"];
[[citiesRef queryWhereField:@"state" isEqualTo:@"CA"]
    queryWhereField:@"population" isLessThan:@1000000];
ViewController.m

Kotlin+KTX

citiesRef.whereEqualTo("state", "CO").whereEqualTo("name", "Denver")
citiesRef.whereEqualTo("state", "CA").whereLessThan("population", 1000000)
DocSnippets.kt

Java

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
Giava
Query chainedQuery1 = cities.whereEqualTo("state", "CO").whereEqualTo("name", "Denver");
QueryDataSnippets.java
Pitone
cities_ref = db.collection("cities")

denver_query = cities_ref.where(filter=FieldFilter("state", "==", "CO")).where(
    filter=FieldFilter("name", "==", "Denver")
)
large_us_cities_query = cities_ref.where(
    filter=FieldFilter("state", "==", "CA")
).where(filter=FieldFilter("population", ">", 1000000))
snippets.py

Python

cities_ref = db.collection("cities")

denver_query = cities_ref.where(filter=FieldFilter("state", "==", "CO")).where(
    filter=FieldFilter("name", "==", "Denver")
)
large_us_cities_query = cities_ref.where(
    filter=FieldFilter("state", "==", "CA")
).where(filter=FieldFilter("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
Andare
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
Unità
Query chainedQuery = citiesRef
    .WhereEqualTo("State", "CA")
    .WhereEqualTo("Name", "San Francisco");
C#
CollectionReference citiesRef = db.Collection("cities");
Query chainedQuery = citiesRef
    .WhereEqualTo("State", "CA")
    .WhereEqualTo("Name", "San Francisco");
Program.cs
Rubino
chained_query = cities_ref.where("state", "=", "CA").where("name", "=", "San Francisco")
query_data.rb

È possibile eseguire confronti tra intervalli ( < , <= , > , >= ) o diversi ( != ) solo su un singolo campo ed è possibile includere al massimo una clausola array-contains o array-contains-any in una query composta :

Valido : filtri di intervallo su un solo campo

Web modular API

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

Web namespaced API

const q1 = citiesRef.where("state", ">=", "CA").where("state", "<=", "IN");
const q2 = citiesRef.where("state", "==", "CA").where("population", ">", 1000000);
test.firestore.js
Veloce
Nota: questo prodotto non è disponibile sui target watchOS e App Clip.
citiesRef
  .whereField("state", isGreaterThanOrEqualTo: "CA")
  .whereField("state", isLessThanOrEqualTo: "IN")
citiesRef
  .whereField("state", isEqualTo: "CA")
  .whereField("population", isGreaterThan: 1000000)
ViewController.swift
Obiettivo-C
Nota: questo prodotto non è disponibile sui target watchOS e App Clip.
[[citiesRef queryWhereField:@"state" isGreaterThanOrEqualTo:@"CA"]
    queryWhereField:@"state" isLessThanOrEqualTo:@"IN"];
[[citiesRef queryWhereField:@"state" isEqualTo:@"CA"]
    queryWhereField:@"population" isGreaterThan:@1000000];
ViewController.m

Kotlin+KTX

citiesRef.whereGreaterThanOrEqualTo("state", "CA")
    .whereLessThanOrEqualTo("state", "IN")
citiesRef.whereEqualTo("state", "CA")
    .whereGreaterThan("population", 1000000)
DocSnippets.kt

Java

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
Giava
Query validQuery1 =
    cities.whereGreaterThanOrEqualTo("state", "CA").whereLessThanOrEqualTo("state", "IN");
Query validQuery2 = cities.whereEqualTo("state", "CA").whereGreaterThan("population", 1000000);
QueryDataSnippets.java
Pitone
cities_ref = db.collection("cities")
cities_ref.where(filter=FieldFilter("state", ">=", "CA")).where(
    filter=FieldFilter("state", "<=", "IN")
)
snippets.py

Python

cities_ref = db.collection("cities")
cities_ref.where(filter=FieldFilter("state", ">=", "CA")).where(
    filter=FieldFilter("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
Andare
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
Unità
Query rangeQuery = citiesRef
    .WhereGreaterThanOrEqualTo("State", "CA")
    .WhereLessThanOrEqualTo("State", "IN");
C#
CollectionReference citiesRef = db.Collection("cities");
Query rangeQuery = citiesRef
    .WhereGreaterThanOrEqualTo("State", "CA")
    .WhereLessThanOrEqualTo("State", "IN");
Program.cs
Rubino
range_query = cities_ref.where("state", ">=", "CA").where("state", "<=", "IN")
query_data.rb

Non valido : filtri di intervallo su campi diversi

Web modular API

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

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

Web namespaced API

citiesRef.where("state", ">=", "CA").where("population", ">", 100000);
test.firestore.js
Veloce
Nota: questo prodotto non è disponibile sui target watchOS e App Clip.
Nota: questo prodotto non è disponibile sui target watchOS e App Clip.
citiesRef
  .whereField("state", isGreaterThanOrEqualTo: "CA")
  .whereField("population", isGreaterThan: 1000000)
ViewController.swift
Obiettivo-C
Nota: questo prodotto non è disponibile sui target watchOS e App Clip.
[[citiesRef queryWhereField:@"state" isGreaterThanOrEqualTo:@"CA"]
    queryWhereField:@"population" isGreaterThan:@1000000];
ViewController.m

Kotlin+KTX

citiesRef.whereGreaterThanOrEqualTo("state", "CA")
    .whereGreaterThan("population", 100000)
DocSnippets.kt

Java

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
Giava
Query invalidRangeQuery =
    cities.whereGreaterThanOrEqualTo("state", "CA").whereGreaterThan("population", 100000);
QueryDataSnippets.java
Pitone
cities_ref = db.collection("cities")
cities_ref.where(filter=FieldFilter("state", ">=", "CA")).where(
    filter=FieldFilter("population", ">=", 1000000)
)
snippets.py

Python

cities_ref = db.collection("cities")
cities_ref.where(filter=FieldFilter("state", ">=", "CA")).where(
    filter=FieldFilter("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
Andare
query := cities.Where("state", ">=", "CA").Where("population", ">", 1000000)
query.go
PHP
$invalidRangeQuery = $citiesRef
    ->where('state', '>=', 'CA')
    ->where('population', '>', 1000000);
query_filter_range_invalid.php
Unità
Query invalidRangeQuery = citiesRef
    .WhereGreaterThanOrEqualTo("State", "CA")
    .WhereGreaterThan("Population", 1000000);
C#
CollectionReference citiesRef = db.Collection("cities");
Query invalidRangeQuery = citiesRef
    .WhereGreaterThanOrEqualTo("State", "CA")
    .WhereGreaterThan("Population", 1000000);
Program.cs
Rubino
invalid_range_query = cities_ref.where("state", ">=", "CA").where("population", ">", 1_000_000)
query_data.rb

OR query

È possibile combinare i vincoli con un OR logico. Per esempio:

Web modular API

const q = query(citiesRef,  
  or(where('capital', '==', true),
     where('population', '>=', 1000000)
  )
);

Web namespaced API

Non disponibile.

Veloce
let query = db.collection("cities").whereFilter(Filter.orFilter([
                Filter.whereField("capital", isEqualTo: true),
                Filter.whereField("population", isGreaterThanOrEqualTo: 1000000);
            ]))
Obiettivo-C
  FIRCollectionReference *collection = [self.db collectionWithPath:@"cities"];
  FIRQuery *query = [collection queryWhereFilter:[FIRFilter orFilterWithFilters:@[
      [FIRFilter filterWhereField:@"capital" isEqualTo:@YES],
      [FIRFilter filterWhereField:@"population" isGreaterThanOrEqualTo:@1000000]
  ]]];

Kotlin+KTX

val query = collection.where(Filter.or(
        Filter.equalTo("capital", true),
        Filter.greaterThanOrEqualTo("population", 1000000)    
))

Java

Query query = collection.where(Filter.or(
        Filter.equalTo("capital", true),
        Filter.greaterThanOrEqualTo("population", 1000000)
));

Dart

var query = db.collection("cities")
  .where(
    Filter.or(
      Filter("capital", isEqualTo: true),
      Filter("population", isGreaterThan: 1000000)
    ));
firestore.dart
Giava

Frammento non disponibile.

Pitone
from google.cloud import firestore
from google.cloud.firestore_v1.base_query import FieldFilter, Or


def query_or_composite_filter(project_id: str) -> None:
    # Instantiate the Firestore client
    client = firestore.Client(project=project_id)
    col_ref = client.collection("users")

    filter_1 = FieldFilter("birthYear", "==", 1906)
    filter_2 = FieldFilter("birthYear", "==", 1912)

    # Create the union filter of the two filters (queries)
    or_filter = Or(filters=[filter_1, filter_2])

    # Execute the query
    docs = col_ref.where(filter=or_filter).stream()

    print("Documents found:")
    for doc in docs:
        print(f"ID: {doc.id}")


query_filter_or.py

Python

Frammento non disponibile.

C++

Frammento non disponibile.

Node.js
const bigCities = await citiesRef
  .where(
    Filter.or(
      Filter.where('capital', '==', true),
      Filter.where('population', '>=', 1000000)
    )
  )
  .get();
index.js
Andare
import (
	"context"
	"fmt"
	"io"

	firestore "cloud.google.com/go/firestore"
	"google.golang.org/api/iterator"
)

func queryFilterOr(w io.Writer, projectId string) error {
	// Instantiate a client
	ctx := context.Background()
	client, err := firestore.NewClient(ctx, projectId)
	if err != nil {
		return err
	}
	// always be sure to close the client to release resources
	defer client.Close()

	q1 := firestore.PropertyFilter{
		Path:     "birthYear",
		Operator: "==",
		Value:    1906,
	}

	q2 := firestore.PropertyFilter{
		Path:     "birthYear",
		Operator: "==",
		Value:    1815,
	}

	orFilter := firestore.OrFilter{
		Filters: []firestore.EntityFilter{q1, q2},
	}

	orQuery := client.Collection("users").WhereEntity(orFilter)
	it := orQuery.Documents(ctx)
	if err != nil {
		return err
	}

	fmt.Fprint(w, "Individual documents:\n")
	for {
		doc, err := it.Next()
		if err == iterator.Done {
			break
		}
		if err != nil {
			return fmt.Errorf("documents iterator: %w", err)
		}
		fmt.Fprintf(w, "%s: %s", doc.Ref.ID, doc.Data()["birthYear"])
	}

	return nil
}

query_filter_or.go
PHP

Frammento non disponibile.

Unità
Query query = citiesRef.Where(Filter.Or(
        Filter.EqualTo("State", "CA"),
        Filter.GreaterThanOrEqualTo("population", 1000000)
));
query.GetSnapshotAsync().ContinueWithOnMainThread((querySnapshotTask) =>
{
    foreach (DocumentSnapshot documentSnapshot in querySnapshotTask.Result.Documents)
    {
        Debug.Log(String.Format("Document {0} returned by query State=CA or population >= {1}", documentSnapshot.Id, 1000000));
    } 
});
C#

Frammento non disponibile.

Rubino

Frammento non disponibile.

Cloud Firestore utilizza i tuoi indici compositi per servire query OR . Se i tuoi indici non supportano la query, Cloud Firestore suggerisce indici aggiuntivi per il tuo database .

È possibile combinare query OR con query composte per filtrare combinazioni di operazioni OR e AND . Per esempio:

Web modular API

const q = query(collection(db, "cities"), and(
  where('state', '==', 'CA'),   
  or(
    where('capital', '==', true),
    where('population', '>=', 1000000)
  )
));
test.firestore.js

Web namespaced API

Non disponibile.

Veloce
Nota: questo prodotto non è disponibile sui target watchOS e App Clip.
let query = db.collection("cities").whereFilter(Filter.andFilter([
    Filter.whereField("state", isEqualTo: "CA"),
    Filter.orFilter([
        Filter.whereField("capital", isEqualTo: true),
        Filter.whereField("population", isGreaterThanOrEqualTo: 1000000);
    ])
]))
ViewController.swift
Obiettivo-C
Nota: questo prodotto non è disponibile sui target watchOS e App Clip.
FIRCollectionReference *collection = [self.db collectionWithPath:@"cities"];
FIRQuery *query = [collection queryWhereFilter:[FIRFilter andFilterWithFilters:@[
  [FIRFilter filterWhereField:@"state" isEqualTo:@"CA"],
  [FIRFilter orFilterWithFilters:@[
    [FIRFilter filterWhereField:@"capital" isEqualTo:@YES],
    [FIRFilter filterWhereField:@"population" isGreaterThanOrEqualTo:@1000000]
  ]]
]]];
ViewController.m

Kotlin+KTX

val query = collection.where(Filter.and(
    Filter.equalTo("state", "CA"),
    Filter.or(
        Filter.equalTo("capital", true),
        Filter.greaterThanOrEqualTo("population", 1000000)
    )
))
DocSnippets.kt

Java

Query query = collection.where(Filter.and(
    Filter.equalTo("state", "CA"),
    Filter.or(
        Filter.equalTo("capital", true),
        Filter.greaterThanOrEqualTo("population", 1000000)
    )
));
DocSnippets.java

Dart

var query = db.collection("cities")
  .where(
    Filter.and(
      Filter("state", isEqualTo: "CA"),
    Filter.or(
      Filter("capital", isEqualTo: true),
      Filter("population", isGreaterThan: 1000000)
    )));
firestore.dart
Giava

Frammento non disponibile.

Pitone

Frammento non disponibile.

Python

Frammento non disponibile.

C++

Frammento non disponibile.

Node.js
const bigCitiesInCalifornia = await citiesRef
  .where('state', '==', 'CA')
  .where(
    Filter.or(
      Filter.where('capital', '==', true),
      Filter.where('population', '>=', 1000000)
    )
  )
  .get();
index.js
Andare

Frammento non disponibile.

PHP

Frammento non disponibile.

Unità
Query query = citiesRef.Where(Filter.And(
    Filter.EqualTo("state", "CA"),
    Filter.Or(
        Filter.EqualTo("capital", true),
        Filter.GreaterThanOrEqualTo("population", 1000000)
    )
));
C#

Frammento non disponibile.

Rubino

Frammento non disponibile.

Limitazioni

Tieni presenti le seguenti limitazioni per or query:

Per una descrizione completa delle limitazioni, consulta Limitazioni delle query .

Query sul gruppo di raccolta

Un gruppo di raccolte è costituito da tutte le raccolte con lo stesso ID. Per impostazione predefinita, le query recuperano i risultati da una singola raccolta nel database. Utilizzare una query del gruppo di raccolte per recuperare documenti da un gruppo di raccolte anziché da una singola raccolta.

Ad esempio, puoi creare un gruppo di raccolte landmarks aggiungendo una sottoraccolta di punti di riferimento a ciascuna città:

Web modular API

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

Web namespaced API

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
Veloce
Nota: questo prodotto non è disponibile sui target watchOS e App Clip.
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
Obiettivo-C
Nota: questo prodotto non è disponibile sui target watchOS e App Clip.
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

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

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
Giava
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
Pitone
cities = db.collection("cities")

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

Python

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++
// Get a new write batch
WriteBatch batch = db->batch();

DocumentReference sf_ref = db->Collection("cities").Document("SF");
batch.Set(sf_ref,{{"name", FieldValue::String("Golden Gate Bridge")}, {"type", FieldValue::String("bridge")}});
batch.Set(sf_ref,{{"name", FieldValue::String("Legion of Honor")}, {"type", FieldValue::String("museum")}});

DocumentReference la_ref = db->Collection("cities").Document("LA");
batch.Set(la_ref,{{"name", FieldValue::String("Griffith Park")}, {"type", FieldValue::String("park")}});
batch.Set(la_ref,{{"name", FieldValue::String("The Getty")}, {"type", FieldValue::String("museum")}});

DocumentReference dc_ref = db->Collection("cities").Document("DC");
batch.Set(dc_ref,{{"name", FieldValue::String("Lincoln Memorial")}, {"type", FieldValue::String("memorial")}});
batch.Set(dc_ref,{{"name", FieldValue::String("National Air and Space Museum")}, {"type", FieldValue::String("museum")}});

DocumentReference tok_ref = db->Collection("cities").Document("TOK");
batch.Set(tok_ref,{{"name", FieldValue::String("Ueno Park")}, {"type", FieldValue::String("park")}});
batch.Set(tok_ref,{{"name", FieldValue::String("National Museum of Nature and Science")}, {"type", FieldValue::String("museum")}});

DocumentReference bj_ref = db->Collection("cities").Document("BJ");
batch.Set(bj_ref,{{"name", FieldValue::String("Jingshan Park")}, {"type", FieldValue::String("park")}});
batch.Set(bj_ref,{{"name", FieldValue::String("Beijing Ancient Observatory")}, {"type", FieldValue::String("museum")}});

// Commit the batch
batch.Commit().OnCompletion([](const Future<void>& future) {
  if (future.error() == Error::kErrorOk) {
    std::cout << "Write batch success!" << std::endl;
  } else {
    std::cout << "Write batch failure: " << future.error_message() << std::endl;
  }
});
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
Andare
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: %w", 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: %w", 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
Unità
List<Task<DocumentReference>> futures =
    new List<Task<DocumentReference>>(){
        citiesRef
            .Document("SF")
            .Collection("landmarks")
            .AddAsync(
                new Dictionary<string, object>()
                {
                    {"name", "Golden Gate Bridge"},
                    {"type", "bridge"},
                }
                ),
        citiesRef
            .Document("SF")
            .Collection("landmarks")
            .AddAsync(
                new Dictionary<string, object>()
                {
                    {"name", "Legion of Honor"},
                    {"type", "museum"},
                }
                ),
        citiesRef
            .Document("LA")
            .Collection("landmarks")
            .AddAsync(
                new Dictionary<string, object>() 
                {
                    {"name", "Griffith Park"},
                    {"type", "park"},
                }
                ),
        citiesRef
            .Document("LA")
            .Collection("landmarks")
            .AddAsync(
                new Dictionary<string, object>() 
                {
                    {"name", "The Getty"},
                    {"type", "museum"},
                }
                ),
        citiesRef
            .Document("DC")
            .Collection("landmarks")
            .AddAsync(
                new Dictionary<string, object>() 
                {
                    {"name", "Lincoln Memorial"},
                    {"type", "memorial"},
                }
                ),
        citiesRef
            .Document("DC")
            .Collection("landmarks")
            .AddAsync(
                new Dictionary<string, object>()
                {
                    {"name", "National Air and Space Museum"},
                    {"type", "museum"},
                }
                ),
        citiesRef
            .Document("TOK")
            .Collection("landmarks")
            .AddAsync(
                new Dictionary<string, object>()
                {
                    {"name", "Ueno Park"},
                    {"type", "park"},
                }
                ),
        citiesRef
            .Document("TOK")
            .Collection("landmarks")
            .AddAsync(
                new Dictionary<string, object>()
                {
                    {"name", "National Museum of Nature and Science"},
                    {"type", "museum"},
                }
                ),
        citiesRef
            .Document("BJ")
            .Collection("landmarks")
            .AddAsync(
                new Dictionary<string, object>()
                {
                    {"name", "Jingshan Park"},
                    {"type", "park"},
                }
                ),
        citiesRef
            .Document("BJ")
            .Collection("landmarks")
            .AddAsync(
                new Dictionary<string, object>()
                {
                    {"name", "Beijing Ancient Observatory"},
                    {"type", "museum"},
                }
                )};
DocumentReference[] landmarks = Task.WhenAll(futures).Result;
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);
            }
        }

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

        private static void InvalidRangeQuery(string project)
        {
            FirestoreDb db = FirestoreDb.Create(project);
            CollectionReference citiesRef = db.Collection("cities");
            Query invalidRangeQuery = citiesRef
                .WhereGreaterThanOrEqualTo("State", "CA")
                .WhereGreaterThan("Population", 1000000);
        }

        public static void Main(string[] args)
        {
            if (args.Length < 2)
            {
                Console.Write(Usage);
                return;
            }
            string command = args[0].ToLower();
            string project = string.Join(" ",
                new ArraySegment<string>(args, 1, args.Length - 1));
            switch (command)
            {
                case "query-create-examples":
                    QueryCreateExamples(project).Wait();
                    break;

                case "create-query-state":
                    CreateQueryState(project).Wait();
                    break;

                case "create-query-capital":
                    CreateQueryCapital(project).Wait();
                    break;

                case "simple-queries":
                    SimpleQueries(project).Wait();
                    break;

                case "array-contains-query":
                    ArrayContainsQuery(project).Wait();
                    break;

                case "array-contains-any-query":
                    ArrayContainsAnyQuery(project).Wait();
                    break;

                case "in-query":
                    InQueryWithoutArray(project).Wait();
                    break;

                case "in-query-array":
                    InQueryWithArray(project).Wait();
                    break;

                case "collection-group-query":
                    CollectionGroupQuery(project).Wait();
                    break;

                case "chained-query":
                    ChainedQuery(project).Wait();
                    break;

                case "composite-index-chained-query":
                    CompositeIndexChainedQuery(project).Wait();
                    break;

                case "range-query":
                    RangeQuery(project).Wait();
                    break;

                case "invalid-range-query":
                    InvalidRangeQuery(project);
                    break;

                default:
                    Console.Write(Usage);
                    return;
            }
        }
    }
}

Program.cs
Rubino
cities_ref = firestore.col collection_path

sf_landmarks = cities_ref.document("SF").collection("landmarks")
sf_landmarks.document.set(
  {
    name: "Golden Gate Bridge",
    type: "bridge"
  }
)
sf_landmarks.document.set(
  {
    name: "Legion of Honor",
    type: "museum"
  }
)

la_landmarks = cities_ref.document("LA").collection("landmarks")
la_landmarks.document.set(
  {
    name: "Griffith Park",
    type: "park"
  }
)
la_landmarks.document.set(
  {
    name: "The Getty",
    type: "museum"
  }
)

dc_landmarks = cities_ref.document("DC").collection("landmarks")
dc_landmarks.document.set(
  {
    name: "Lincoln Memorial",
    type: "memorial"
  }
)
dc_landmarks.document.set(
  {
    name: "National Air and Space Museum",
    type: "museum"
  }
)

tok_landmarks = cities_ref.document("TOK").collection("landmarks")
tok_landmarks.document.set(
  {
    name: "Ueno Park",
    type: "park"
  }
)
tok_landmarks.document.set(
  {
    name: "National Museum of Nature and Science",
    type: "museum"
  }
)

bj_landmarks = cities_ref.document("BJ").collection("landmarks")
bj_landmarks.document.set(
  {
    name: "Jingshan Park",
    type: "park"
  }
)
bj_landmarks.document.set(
  {
    name: "Beijing Ancient Observatory",
    type: "museum"
  }
)
query_data.rb

Possiamo utilizzare la query semplice e composta descritta in precedenza per interrogare la sottoraccolta landmarks di una singola città, ma potresti anche voler recuperare i risultati dalla sottoraccolta landmarks di ogni città contemporaneamente.

Il gruppo di raccolta landmarks è costituito da tutte le raccolte con l'ID landmarks ed è possibile interrogarlo utilizzando una query del gruppo di raccolta. Ad esempio, questa query del gruppo di raccolte recupera tutti i punti di riferimento museum in tutte le città:

Web modular API

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

const museums = query(collectionGroup(db, 'landmarks'), where('type', '==', 'museum'));
const querySnapshot = await getDocs(museums);
querySnapshot.forEach((doc) => {
    console.log(doc.id, ' => ', doc.data());
});
fs_collection_group_query.js

Web namespaced API

var museums = db.collectionGroup('landmarks').where('type', '==', 'museum');
museums.get().then((querySnapshot) => {
    querySnapshot.forEach((doc) => {
        console.log(doc.id, ' => ', doc.data());
    });
});
test.firestore.js
Veloce
Nota: questo prodotto non è disponibile sui target watchOS e App Clip.
db.collectionGroup("landmarks").whereField("type", isEqualTo: "museum").getDocuments { (snapshot, error) in
  // ...
}
ViewController.swift
Obiettivo-C
Nota: questo prodotto non è disponibile sui target watchOS e App Clip.
[[[self.db collectionGroupWithID:@"landmarks"] queryWhereField:@"type" isEqualTo:@"museum"]
    getDocumentsWithCompletion:^(FIRQuerySnapshot *snapshot, NSError *error) {
    // ...
}];
ViewController.m

Kotlin+KTX

db.collectionGroup("landmarks").whereEqualTo("type", "museum").get()
    .addOnSuccessListener { queryDocumentSnapshots ->
        // ...
    }
DocSnippets.kt

Java

db.collectionGroup("landmarks").whereEqualTo("type", "museum").get()
        .addOnSuccessListener(new OnSuccessListener<QuerySnapshot>() {
            @Override
            public void onSuccess(QuerySnapshot queryDocumentSnapshots) {
                // ...
            }
        });
DocSnippets.java

Dart

db
    .collectionGroup("landmarks")
    .where("type", isEqualTo: "museum")
    .get()
    .then(
      (res) => print("Successfully completed"),
      onError: (e) => print("Error completing: $e"),
    );
firestore.dart
Giava
final Query museums = db.collectionGroup("landmarks").whereEqualTo("type", "museum");
final ApiFuture<QuerySnapshot> querySnapshot = museums.get();
for (DocumentSnapshot document : querySnapshot.get().getDocuments()) {
  System.out.println(document.getId());
}
QueryDataSnippets.java
Pitone
museums = db.collection_group("landmarks").where(
    filter=FieldFilter("type", "==", "museum")
)
docs = museums.stream()
for doc in docs:
    print(f"{doc.id} => {doc.to_dict()}")
snippets.py

Python

museums = db.collection_group("landmarks").where(
    filter=FieldFilter("type", "==", "museum")
)
docs = museums.stream()
async for doc in docs:
    print(f"{doc.id} => {doc.to_dict()}")
snippets.py
C++
db->CollectionGroup("landmarks")
.WhereEqualTo("type", FieldValue::String("museum")).Get()
.OnCompletion([](const firebase::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;
  }
});
Node.js
const querySnapshot = await db.collectionGroup('landmarks').where('type', '==', 'museum').get();
querySnapshot.forEach((doc) => {
  console.log(doc.id, ' => ', doc.data());
});
index.js
Andare
import (
	"context"
	"fmt"
	"io"

	"cloud.google.com/go/firestore"
	"google.golang.org/api/iterator"
)

// collectionGroupQuery runs a collection group query over the data created by
// collectionGroupSetup.
func collectionGroupQuery(w io.Writer, projectID string) error {
	ctx := context.Background()

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

	it := client.CollectionGroup("landmarks").Where("type", "==", "museum").Documents(ctx)
	for {
		doc, err := it.Next()
		if err == iterator.Done {
			break
		}
		if err != nil {
			return fmt.Errorf("documents iterator: %w", err)
		}
		fmt.Fprintf(w, "%s: %s", doc.Ref.ID, doc.Data()["name"])
	}

	return nil
}

collection_group_query.go
PHP
$museums = $db->collectionGroup('landmarks')->where('type', '==', 'museum');
foreach ($museums->documents() as $document) {
    printf('%s => %s' . PHP_EOL, $document->id(), $document->data()['name']);
}
query_collection_group_filter_eq.php
Unità
Query museums = db.CollectionGroup("landmarks").WhereEqualTo("type", "museum");
museums.GetSnapshotAsync().ContinueWithOnMainThread((querySnapshotTask) =>
{
    foreach (DocumentSnapshot documentSnapshot in querySnapshotTask.Result.Documents)
    {
        Debug.Log(String.Format("Document {0} returned by query State=CA", documentSnapshot.Id));
    } 
});
C#
Query museums = db.CollectionGroup("landmarks").WhereEqualTo("Type", "museum");
QuerySnapshot querySnapshot = await museums.GetSnapshotAsync();
foreach (DocumentSnapshot document in querySnapshot.Documents)
{
    Console.WriteLine($"{document.Reference.Path}: {document.GetValue<string>("Name")}");
}
Program.cs
Rubino
museums = firestore.collection_group("landmarks").where("type", "==", "museum")
museums.get do |museum|
  puts "#{museum[:type]} name is #{museum[:name]}."
end
query_data.rb

Prima di utilizzare una query del gruppo di raccolta, è necessario creare un indice che supporti la query del gruppo di raccolta. Puoi creare un indice tramite un messaggio di errore, la console o la CLI di Firebase .

Per gli SDK Web e mobili, devi anche creare regole che consentano le query del gruppo di raccolta .

Limitazioni delle query

L'elenco seguente riepiloga le limitazioni delle query di Cloud Firestore:

  • Cloud Firestore fornisce supporto per query OR logiche tramite gli operatori or , in e array-contains-any . Queste query sono limitate a 30 disgiunzioni basate sulla forma normale disgiuntiva della query .
  • In una query composta, i confronti tra intervalli ( < , <= , > , >= ) e diversi da ( != , not-in ) devono essere tutti filtrati sullo stesso campo.
  • È possibile utilizzare al massimo una clausola array-contains per disgiunzione ( or gruppo). Non è possibile combinare array-contains con array-contains-any nella stessa disgiunzione.
  • Non è possibile combinare not-in con in , array-contains-any o or nella stessa query.
  • È consentito solo un singolo not-in o != ` per query.
  • not-in supporta fino a 10 valori di confronto.
  • La somma di filtri, ordinamenti e percorso del documento principale (1 per una sottoraccolta, 0 per una raccolta radice) in una query non può superare 100. Questo viene calcolato in base alla forma normale disgiuntiva della query .
  • Una query con un filtro di disuguaglianza su un campo implica l'ordinamento in base a quel campo e filtri per l'esistenza di quel campo .

Limiti sulle query OR

Per evitare che una query diventi troppo costosa dal punto di vista computazionale, Cloud Firestore limita il numero di clausole AND e OR che puoi combinare. Per applicare questo limite, Cloud Firestore converte le query che eseguono operazioni OR logiche ( or , in e array-contains-any ) nella forma normale disgiuntiva (nota anche come OR di AND ). Cloud Firestore limita una query a un massimo di 30 disgiunzioni in forma normale disgiuntiva.

Forma normale disgiuntiva

Cloud Firestore converte le query nella forma normale disgiuntiva applicando due regole:

  • Appiattire

    Date le condizioni A , B e C :

    A and (B and C) => A and B and C

  • Diritto distributivo

    Date le condizioni A , B , C e D :

    • A and (B or C) => (A and B) or (A and C)
    • (A or B) and (C or D) => (A and C) or (A and D) or (B and C) or (B and D)

Quando applichi queste regole alle query in e array-contains-any , ricorda che questi operatori sono abbreviazioni di OR . Ad esempio, a in [1,2] è una scorciatoia per a = 1 OR a = 2 .

I seguenti esempi mostrano il numero di disgiunzioni per diverse query:

Domanda Numero di disgiunzioni
query(collectionRef, where("a", "==", 1))
1
query(collectionRef, or( where("a", "==", 1), where("b", "==", 2) ))
2
query(collectionRef,
        or( and( where("a", "==", 1), where("c", "==", 3) ),
            and( where("a", "==", 1), where("d", "==", 4) ),
            and( where("b", "==", 2), where("c", "==", 3) ),
            and( where("b", "==", 2), where("d", "==", 4) )
        )
      )
4
query(collectionRef,
        and( or( where("a", "==", 1), where("b", "==", 2) ),
             or( where("c", "==", 3), where("d", "==", 4) )
        )
      )

4

La forma normale disgiuntiva di questa query è uguale alla query precedente.

query(collectionRef, where("a", "in", [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]) )
10
query(collectionRef,
        and( where("a", "in", [1, 2, 3, 4, 5]),
             where("b", "in", [1, 2, 3, 4, 5, 6, 7, 8, 9, 10])
        )
      )

50

Questa query restituisce un errore perché supera il limite di 30 disgiunzioni.

query(collectionRef,
        or( where("a", "in", [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]),
            where("b", "in", [1, 2, 3, 4, 5, 6, 7, 8, 9, 10])
        )
      )
20
query(collectionRef,
        and( where("a", "in", [1, 2, 3, 4, 5]),
             or( where("b", "==", 2),
                 where("c", "==", 3)
             )
        )
      )
10

orderBy ed esistenza

Quando ordini una query in base a un determinato campo, la query può restituire solo i documenti in cui esiste il campo ordinato per.

Ad esempio, la query seguente non restituirebbe alcun documento in cui il campo population non è impostato, anche se soddisfano altrimenti i filtri della query.

Giava
db.collection("cities").whereEqualTo("country", “USA”).orderBy(“population”);

Un effetto correlato si applica alle disuguaglianze. Una query con un filtro di disuguaglianza su un campo implica anche l'ordinamento in base a quel campo. La seguente query non restituisce documenti senza un campo population anche se country = USA in quel documento. Come soluzione alternativa, è possibile eseguire query separate per ciascun ordinamento oppure assegnare un valore per tutti i campi in base all'ordine.

Giava
db.collection(“cities”).where(or(“country”, USA”), greaterThan(“population”, 250000));

La query precedente include un ordine implicito sulla disuguaglianza ed è equivalente alla seguente:

Giava
db.collection(“cities”).where(or(“country”, USA”), greaterThan(“population”, 250000)).orderBy(“population”);

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