Com o Cloud Firestore, você tem um recurso de consulta eficiente para especificar os
documentos que pretende recuperar de uma coleção ou grupo de coleções. Essas
consultas também podem ser usadas com get()
ou addSnapshotListener()
, conforme
descrito em Retornar dados e Receber atualizações em tempo real.
Dados de exemplo
Para começar, escreva alguns dados sobre cidades para demonstrarmos diversas formas de leitura:
Web
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"] });
Web
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"] });
Swift
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"] ])
Objective-C
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"] }];
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)
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);
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);
Java
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") 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() )
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() )
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")})}, });
Node.js
Go
PHP
Unity
CollectionReference citiesRef = db.Collection("cities"); citiesRef.Document("SF").SetAsync(new Dictionary<string, object>(){ { "Name", "San Francisco" }, { "State", "CA" }, { "Country", "USA" }, { "Capital", false }, { "Population", 860000 }, { "Regions", new ArrayList{"west_coast", "norcal"} } }); citiesRef.Document("LA").SetAsync(new Dictionary<string, object>(){ { "Name", "Los Angeles" }, { "State", "CA" }, { "Country", "USA" }, { "Capital", false }, { "Population", 3900000 }, { "Regions", new ArrayList{"west_coast", "socal"} } }); citiesRef.Document("DC").SetAsync(new Dictionary<string, object>(){ { "Name", "Washington D.C." }, { "State", null }, { "Country", "USA" }, { "Capital", true }, { "Population", 680000 }, { "Regions", new ArrayList{"east_coast"} } }); citiesRef.Document("TOK").SetAsync(new Dictionary<string, object>(){ { "Name", "Tokyo" }, { "State", null }, { "Country", "Japan" }, { "Capital", true }, { "Population", 9000000 }, { "Regions", new ArrayList{"kanto", "honshu"} } }); citiesRef.Document("BJ").SetAsync(new Dictionary<string, object>(){ { "Name", "Beijing" }, { "State", null }, { "Country", "China" }, { "Capital", true }, { "Population", 21500000 }, { "Regions", new ArrayList{"jingjinji", "hebei"} } });
C#
Ruby
Consultas simples
A seguinte consulta mostra todas as cidades do estado CA
:
Web
// 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"));
Web
// Create a reference to the cities collection var citiesRef = db.collection("cities"); // Create a query against the collection. var query = citiesRef.where("state", "==", "CA");
Swift
// 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")
Objective-C
// 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"];
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")
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");
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");
Java
Python
Python
C++
CollectionReference cities_ref = db->Collection("cities"); // Create a query against the collection. Query query_ca = cities_ref.WhereEqualTo("state", FieldValue::String("CA"));
Node.js
Go
PHP
Unity
CollectionReference citiesRef = db.Collection("cities"); Query query = citiesRef.WhereEqualTo("State", "CA"); query.GetSnapshotAsync().ContinueWithOnMainThread((querySnapshotTask) => { foreach (DocumentSnapshot documentSnapshot in querySnapshotTask.Result.Documents) { Debug.Log(String.Format("Document {0} returned by query State=CA", documentSnapshot.Id)); } });
C#
Ruby
A consulta a seguir retorna todas as capitais:
Web
import { collection, query, where } from "firebase/firestore"; const citiesRef = collection(db, "cities"); const q = query(citiesRef, where("capital", "==", true));
Web
var citiesRef = db.collection("cities"); var query = citiesRef.where("capital", "==", true);
Swift
let capitalCities = db.collection("cities").whereField("capital", isEqualTo: true)
Objective-C
FIRQuery *capitalCities = [[self.db collectionWithPath:@"cities"] queryWhereField:@"capital" isEqualTo:@YES];
Kotlin+KTX
val capitalCities = db.collection("cities").whereEqualTo("capital", true)
Java
Query capitalCities = db.collection("cities").whereEqualTo("capital", true);
Dart
final capitalcities = db.collection("cities").where("capital", isEqualTo: true);
Java
Python
Python
C++
Query capital_cities = db->Collection("cities").WhereEqualTo( "capital", FieldValue::Boolean(true));
Node.js
Go
PHP
Unity
CollectionReference citiesRef = db.Collection("cities"); Query query = citiesRef.WhereEqualTo("Capital", true); query.GetSnapshotAsync().ContinueWithOnMainThread((querySnapshotTask) => { foreach (DocumentSnapshot documentSnapshot in querySnapshotTask.Result.Documents) { Debug.Log(String.Format("Document {0} returned by query Capital=true", documentSnapshot.Id)); } });
C#
Ruby
Executar uma consulta
Depois de criar um objeto de consulta, use a função get()
para conseguir os resultados:
Web
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()); });
Web
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); });
Swift
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)") }
Objective-C
[[[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); } } }];
Kotlin+KTX
db.collection("cities") .whereEqualTo("capital", true) .get() .addOnSuccessListener { documents -> for (document in documents) { Log.d(TAG, "${document.id} => ${document.data}") } } .addOnFailureListener { exception -> Log.w(TAG, "Error getting documents: ", exception) }
Java
db.collection("cities") .whereEqualTo("capital", true) .get() .addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() { @Override public void onComplete(@NonNull Task<QuerySnapshot> task) { if (task.isSuccessful()) { for (QueryDocumentSnapshot document : task.getResult()) { Log.d(TAG, document.getId() + " => " + document.getData()); } } else { Log.d(TAG, "Error getting documents: ", task.getException()); } } });
Dart
db.collection("cities").where("capital", isEqualTo: true).get().then( (querySnapshot) { print("Successfully completed"); for (var docSnapshot in querySnapshot.docs) { print('${docSnapshot.id} => ${docSnapshot.data()}'); } }, onError: (e) => print("Error completing: $e"), );
Java
Python
Python
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; } });
Node.js
Go
PHP
PHP
Para mais informações sobre como instalar e criar um cliente do Cloud Firestore, consulte Bibliotecas de cliente do Cloud Firestore.
Unity
Query capitalQuery = db.Collection("cities").WhereEqualTo("Capital", true); capitalQuery.GetSnapshotAsync().ContinueWithOnMainThread(task => { QuerySnapshot capitalQuerySnapshot = task.Result; foreach (DocumentSnapshot documentSnapshot in capitalQuerySnapshot.Documents) { Debug.Log(String.Format("Document data for {0} document:", documentSnapshot.Id)); Dictionary<string, object> city = documentSnapshot.ToDictionary(); foreach (KeyValuePair<string, object> pair in city) { Debug.Log(String.Format("{0}: {1}", pair.Key, pair.Value)); } // Newline to separate entries Debug.Log(""); }; });
C#
Ruby
Consulte Receber dados para mais informações sobre como recuperar os resultados da consulta. Também é possível adicionar um listener a uma consulta para receber os resultados atuais e detectar futuras atualizações.
Operadores de consulta
O método where()
usa três parâmetros: um campo para filtrar, um operador de comparação e um valor. O Cloud Firestore oferece suporte aos seguintes operadores
de comparação:
<
menor que<=
menor que ou igual a==
igual a>
maior que>=
maior que ou igual a!=
diferente dearray-contains
array-contains-any
in
not-in
Exemplo:
Web
const stateQuery = query(citiesRef, where("state", "==", "CA")); const populationQuery = query(citiesRef, where("population", "<", 100000)); const nameQuery = query(citiesRef, where("name", ">=", "San Francisco"));
Web
const stateQuery = citiesRef.where("state", "==", "CA"); const populationQuery = citiesRef.where("population", "<", 100000); const nameQuery = citiesRef.where("name", ">=", "San Francisco");
Swift
let stateQuery = citiesRef.whereField("state", isEqualTo: "CA") let populationQuery = citiesRef.whereField("population", isLessThan: 100000) let nameQuery = citiesRef.whereField("name", isGreaterThanOrEqualTo: "San Francisco")
Objective-C
FIRQuery *stateQuery = [citiesRef queryWhereField:@"state" isEqualTo:@"CA"]; FIRQuery *populationQuery = [citiesRef queryWhereField:@"population" isLessThan:@100000]; FIRQuery *nameQuery = [citiesRef queryWhereField:@"name" isGreaterThanOrEqualTo:@"San Francisco"];
Kotlin+KTX
val stateQuery = citiesRef.whereEqualTo("state", "CA") val populationQuery = citiesRef.whereLessThan("population", 100000) val nameQuery = citiesRef.whereGreaterThanOrEqualTo("name", "San Francisco")
Java
Query stateQuery = citiesRef.whereEqualTo("state", "CA"); Query populationQuery = citiesRef.whereLessThan("population", 100000); Query nameQuery = citiesRef.whereGreaterThanOrEqualTo("name", "San Francisco");
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");
Java
Python
Python
C++
cities_ref.WhereEqualTo("state", FieldValue::String("CA")); cities_ref.WhereLessThan("population", FieldValue::Integer(100000)); cities_ref.WhereGreaterThanOrEqualTo("name", FieldValue::String("San Francisco"));
Node.js
Go
PHP
Unity
Query stateQuery = citiesRef.WhereEqualTo("State", "CA"); Query populationQuery = citiesRef.WhereGreaterThan("Population", 1000000); Query nameQuery = citiesRef.WhereGreaterThanOrEqualTo("Name", "San Francisco");
C#
Ruby
Diferente de (!=
)
Use o operador "diferente de" (!=
) para retornar os documentos em que o campo especificado
existe e não corresponde ao valor da comparação. Exemplo:
Web
const notCapitalQuery = query(citiesRef, where("capital", "!=", false));
Web
citiesRef.where("capital", "!=", false);
Swift
let notEqualQuery = citiesRef.whereField("capital", isNotEqualTo: false)
Objective-C
query = [citiesRef queryWhereField:@"capital" isNotEqualTo:@NO];
Kotlin+KTX
val notCapitalQuery = citiesRef.whereNotEqualTo("capital", false)
Java
Query notCapitalQuery = citiesRef.whereNotEqualTo("capital", false);
Dart
final citiesRef = db.collection("cities"); final notCapitals = citiesRef.where("capital", isNotEqualTo: true);
Java
Python
// Snippet not yet available
C++
cities_ref.WhereNotEqualTo("capital", FieldValue::Boolean(false));
Node.js
Go
// Snippet not yet available
PHP
Unity
Query query = citiesRef.WhereNotEqualTo("capital", false); Query query = citiesRef.WhereNotEqualTo("capital", false);
C#
// Snippet not yet available
Ruby
Essa consulta retorna todos os documentos city
em que o campo capital
existe com um
valor diferente de false
ou null
. Isso inclui os documentos city
em que o
valor do campo capital
é igual a true
ou a qualquer valor não booleano além de null
.
Essa consulta não retorna os documentos city
em que o campo capital
não
existe. As consultas "diferente de" (!=
) e not-in
não selecionam os documentos em que o campo especificado não existe.
Haverá um campo quando ele estiver definido como qualquer valor, incluindo uma string vazia (""
),
null
e NaN
(não numérico). Observe que os valores de campos com null
não
correspondem a cláusulas !=
, porque x != null
é considerado como undefined
.
Limitações
Observe as seguintes limitações para as consultas !=
:
- Apenas os documentos nos quais o campo determinado existe podem corresponder à consulta.
- Não é possível combinar
not-in
e!=
em uma consulta composta. - Em uma consulta composta, as comparações de intervalos (
<
,<=
,>
e>=
) e de valores diferentes (!=
enot-in
) precisam filtrar no mesmo campo.
Associação de matriz
Use o operador array-contains
para filtrar com base nos valores
da matriz. Exemplo:
Web
import { query, where } from "firebase/firestore"; const q = query(citiesRef, where("regions", "array-contains", "west_coast"));
Web
citiesRef.where("regions", "array-contains", "west_coast");
Swift
citiesRef .whereField("regions", arrayContains: "west_coast")
Objective-C
[citiesRef queryWhereField:@"state" arrayContains:@"west_coast"];
Kotlin+KTX
val citiesRef = db.collection("cities") citiesRef.whereArrayContains("regions", "west_coast")
Java
CollectionReference citiesRef = db.collection("cities"); citiesRef.whereArrayContains("regions", "west_coast");
Dart
final citiesRef = db.collection("cities"); final westCoastcities = citiesRef.where("regions", arrayContains: "west_coast");
Java
Python
Python
C++
CollectionReference cities_ref = db->Collection("cities"); cities_ref.WhereArrayContains("region", FieldValue::String("west_coast"));
Node.js
Go
PHP
Unity
CollectionReference citiesRef = db.Collection("cities"); Query arrayContainsQuery = citiesRef.WhereArrayContains("region", "west_coast");
C#
Ruby
Essa consulta retorna todos os documentos city
em que o campo regions
é uma matriz
contendo west_coast
. Se a matriz tiver várias instâncias do valor
consultado, o documento será incluído nos resultados apenas uma vez.
É possível usar no máximo uma cláusula array-contains
por disjunção (grupo or
).
Não é possível combinar array-contains
com array-contains-any
na mesma
disjunção.
in
, not-in
e array-contains-any
Use o operador in
para combinar até 30
cláusulas de igualdade (==
) no mesmo campo utilizando um OR
lógico. Uma consulta in
retorna documentos em que o campo especificado corresponde a qualquer um dos valores de comparação.
Exemplo:
Web
import { query, where } from "firebase/firestore"; const q = query(citiesRef, where('country', 'in', ['USA', 'Japan']));
Web
citiesRef.where('country', 'in', ['USA', 'Japan']);
Swift
let citiesRef = db.collection("cities") citiesRef.whereField("country", in: ["USA", "Japan"])
Objective-C
FIRCollectionReference *citiesRef = [self.db collectionWithPath:@"cities"]; [citiesRef queryWhereField:@"country" in:@[@"USA", @"Japan"]];
Kotlin+KTX
val citiesRef = db.collection("cities") citiesRef.whereIn("country", listOf("USA", "Japan"))
Java
CollectionReference citiesRef = db.collection("cities"); citiesRef.whereIn("country", Arrays.asList("USA", "Japan"));
Dart
final citiesRef = db.collection("cities"); final cities = citiesRef.where("country", whereIn: ["USA", "Japan"]);
Java
Python
Python
C++
CollectionReference cities_ref = db->Collection("cities"); cities_ref.WhereIn("country", std::vector<FieldValue> { FieldValue::String("USA"), FieldValue::String("Japan") });
Node.js
Go
PHP
Unity
CollectionReference citiesRef = db.Collection("cities"); ListcountriesList = new List<object>() {"USA", "Japan"}; Query whereInQuery = citiesRef.WhereIn("country", countriesList);
C#
Ruby
Essa consulta retorna todos os documentos city
em que o campo country
está definido
como USA
ou Japan
. Considerando os dados de exemplo, isso inclui
os documentos SF
, LA
, DC
e TOK
.
not-in
Use o operador not-in
para combinar até 10 cláusulas "diferente de" (!=
) no
mesmo campo utilizando um AND
lógico. Uma consulta not-in
retorna documentos em que o campo especificado existe, não é null
e não corresponde a nenhum dos valores de comparação. Exemplo:
Web
import { query, where } from "firebase/firestore"; const q = query(citiesRef, where('country', 'not-in', ['USA', 'Japan']));
Web
citiesRef.where('country', 'not-in', ['USA', 'Japan']);
Swift
citiesRef.whereField("country", notIn: ["USA", "Japan"])
Objective-C
[citiesRef queryWhereField:@"country" notIn:@[@"USA", @"Japan"]];
Kotlin+KTX
citiesRef.whereNotIn("country", listOf("USA", "Japan"))
Java
citiesRef.whereNotIn("country", Arrays.asList("USA", "Japan"));
Dart
final citiesRef = db.collection("cities"); final cities = citiesRef.where("country", whereNotIn: ["USA", "Japan"]);
Java
Python
// Snippet not yet available
C++
cities_ref.WhereNotIn("country", std::vector<FieldValue> { FieldValue::String("USA"), FieldValue::String("Japan") });
Node.js
Go
// Snippet not yet available
PHP
Unity
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
Ruby
Essa consulta retorna todos os documentos city
em que o campo country
existe e
não está definido como USA
, Japan
ou null
. Considerando os dados de exemplo, isso inclui os
documentos London
e Hong Kong
.
As consultas not-in
não selecionam os documentos em que
o campo especificado não existe. Haverá um campo quando ele estiver definido como qualquer valor,
incluindo uma string vazia (""
), null
e NaN
(não numérico). Observe
que x != null
é considerado como undefined
. Uma consulta not-in
com
null
como um dos valores de comparação não corresponderá a nenhum documento.
array-contains-any
Use o operador array-contains-any
para combinar até 30
cláusulas array-contains
no mesmo campo utilizando um OR
lógico. Uma
consulta array-contains-any
retorna documentos em que o campo especificado é uma matriz
que contém um ou mais valores de comparação:
Web
import { query, where } from "firebase/firestore"; const q = query(citiesRef, where('regions', 'array-contains-any', ['west_coast', 'east_coast']));
Web
citiesRef.where('regions', 'array-contains-any', ['west_coast', 'east_coast']);
Swift
let citiesRef = db.collection("cities") citiesRef.whereField("regions", arrayContainsAny: ["west_coast", "east_coast"])
Objective-C
FIRCollectionReference *citiesRef = [self.db collectionWithPath:@"cities"]; [citiesRef queryWhereField:@"regions" arrayContainsAny:@[@"west_coast", @"east_coast"]];
Kotlin+KTX
val citiesRef = db.collection("cities") citiesRef.whereArrayContainsAny("regions", listOf("west_coast", "east_coast"))
Java
CollectionReference citiesRef = db.collection("cities"); citiesRef.whereArrayContainsAny("regions", Arrays.asList("west_coast", "east_coast"));
Dart
final citiesRef = db.collection("cities"); final cities = citiesRef .where("regions", arrayContainsAny: ["west_coast", "east_coast"]);
Java
Python
Python
C++
CollectionReference cities_ref = db->Collection("cities"); cities_ref.WhereArrayContainsAny("region", std::vector<FieldValue> { FieldValue::String("west_coast"), FieldValue::String("east_coast") });
Node.js
Go
PHP
Unity
Query query = citiesRef.WhereArrayContainsAny( "regions", new List<object>() { new List<object>(){"west_coast"}, new List<object>(){"east_coast"}});
C#
Ruby
Essa consulta retorna todos os documentos de cidades em que o campo regions
é uma matriz
que contém west_coast
ou east_coast
. Considerando os dados de exemplo, isso inclui
os documentos SF
, LA
e DC
.
Os resultados de array-contains-any
são eliminados. Mesmo que o campo da matriz de um documento
corresponda a mais de um dos valores de comparação, o conjunto de resultados incluirá
esse documento apenas uma vez.
array-contains-any
sempre filtra pelo tipo de dado da matriz. Por exemplo, a
consulta acima não retornaria um documento de cidade em que, em vez de uma matriz, o
campo regions
fosse a string west_coast
.
É possível usar um valor de matriz como um valor de comparação para in
, mas, diferentemente de
array-contains-any
, a cláusula corresponderá a uma correspondência exata de comprimento, ordem e valores de matriz. Exemplo:
Web
import { query, where } from "firebase/firestore"; const q = query(citiesRef, where('regions', 'in', [['west_coast'], ['east_coast']]));
Web
citiesRef.where('regions', 'in', [['west_coast'], ['east_coast']]);
Swift
citiesRef.whereField("regions", in: [["west_coast"], ["east_coast"]])
Objective-C
[citiesRef queryWhereField:@"regions" in:@[@[@"west_coast"], @[@"east_coast"]]];
Kotlin+KTX
citiesRef.whereIn("regions", listOf(arrayOf("west_coast"), arrayOf("east_coast")))
Java
citiesRef.whereIn("regions", Arrays.asList(new String[]{"west_coast"}, new String[]{"east_coast"}));
Dart
final citiesRef = db.collection("cities"); final cities = citiesRef.where("regions", whereIn: [ ["west_coast"], ["east_coast"] ]);
Java
Python
Python
C++
cities_ref.WhereIn("region", std::vector<FieldValue> { FieldValue::String("west_coast"), FieldValue::String("east_coast") });
Node.js
Go
PHP
Unity
Query query = citiesRef.WhereIn(new FieldPath("regions"), new List<string>{"west_coast", "east_coast"});
C#
Ruby
Essa consulta retorna todos os documentos de cidades em que o campo regions
é uma matriz que contém exatamente um elemento de west_coast
ou east_coast
.
Considerando os dados de exemplo, apenas o documento DC
se qualifica com seu campo regions
de ["east_coast"]
. No entanto, o documento SF
não corresponde, porque seu campo regions
é ["west_coast", "norcal"]
.
Limitações
Veja abaixo as limitações de in
, not-in
e array-contains-any
:
- O Cloud Firestore é compatível com consultas lógicas
OR
por meio dos operadoresor
,in
earray-contains-any
. Essas consultas são limitadas a 30 disjunções com base no formulário normal disjuntivo da consulta. - É possível usar no máximo uma cláusula
array-contains
por disjunção (grupoor
). Não é possível combinararray-contains
comarray-contains-any
na mesma disjunção. - Não é possível combinar
not-in
com!=
. not-in
aceita até 10 valores de comparação.
Consultas (AND
) compostas
É possível combinar restrições com um AND
lógico encadeando vários operadores
de igualdade (==
ou array-contains
). No entanto, é preciso criar um
índice composto para combinar operadores de igualdade com os operadores
de desigualdade, <
, <=
, >
e !=
.
Web
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));
Web
const q1 = citiesRef.where("state", "==", "CO").where("name", "==", "Denver"); const q2 = citiesRef.where("state", "==", "CA").where("population", "<", 1000000);
Swift
citiesRef .whereField("state", isEqualTo: "CO") .whereField("name", isEqualTo: "Denver") citiesRef .whereField("state", isEqualTo: "CA") .whereField("population", isLessThan: 1000000)
Objective-C
[[citiesRef queryWhereField:@"state" isEqualTo:@"CO"] queryWhereField:@"name" isGreaterThanOrEqualTo:@"Denver"]; [[citiesRef queryWhereField:@"state" isEqualTo:@"CA"] queryWhereField:@"population" isLessThan:@1000000];
Kotlin+KTX
citiesRef.whereEqualTo("state", "CO").whereEqualTo("name", "Denver") citiesRef.whereEqualTo("state", "CA").whereLessThan("population", 1000000)
Java
citiesRef.whereEqualTo("state", "CO").whereEqualTo("name", "Denver"); citiesRef.whereEqualTo("state", "CA").whereLessThan("population", 1000000);
Dart
final citiesRef = db.collection("cities"); citiesRef .where("state", isEqualTo: "CO") .where("name", isEqualTo: "Denver"); citiesRef .where("state", isEqualTo: "CA") .where("population", isLessThan: 1000000);
Java
Python
Python
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));
Node.js
Go
PHP
Unity
Query chainedQuery = citiesRef .WhereEqualTo("State", "CA") .WhereEqualTo("Name", "San Francisco");
C#
Ruby
É possível fazer comparações de intervalos (<
, <=
, >
, >=
) ou de valores diferentes (!=
)
apenas em um único campo e incluir no máximo uma
cláusula array-contains
ou array-contains-any
em uma
consulta composta:
Válido: filtros de intervalo em apenas um campo
Web
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));
Web
const q1 = citiesRef.where("state", ">=", "CA").where("state", "<=", "IN"); const q2 = citiesRef.where("state", "==", "CA").where("population", ">", 1000000);
Swift
citiesRef .whereField("state", isGreaterThanOrEqualTo: "CA") .whereField("state", isLessThanOrEqualTo: "IN") citiesRef .whereField("state", isEqualTo: "CA") .whereField("population", isGreaterThan: 1000000)
Objective-C
[[citiesRef queryWhereField:@"state" isGreaterThanOrEqualTo:@"CA"] queryWhereField:@"state" isLessThanOrEqualTo:@"IN"]; [[citiesRef queryWhereField:@"state" isEqualTo:@"CA"] queryWhereField:@"population" isGreaterThan:@1000000];
Kotlin+KTX
citiesRef.whereGreaterThanOrEqualTo("state", "CA") .whereLessThanOrEqualTo("state", "IN") citiesRef.whereEqualTo("state", "CA") .whereGreaterThan("population", 1000000)
Java
citiesRef.whereGreaterThanOrEqualTo("state", "CA") .whereLessThanOrEqualTo("state", "IN"); citiesRef.whereEqualTo("state", "CA") .whereGreaterThan("population", 1000000);
Dart
final citiesRef = db.collection("cities"); citiesRef .where("state", isGreaterThanOrEqualTo: "CA") .where("state", isLessThanOrEqualTo: "IN"); citiesRef .where("state", isEqualTo: "CA") .where("population", isGreaterThan: 1000000);
Java
Python
Python
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));
Node.js
Go
PHP
Unity
Query rangeQuery = citiesRef .WhereGreaterThanOrEqualTo("State", "CA") .WhereLessThanOrEqualTo("State", "IN");
C#
Ruby
Inválido: filtros de intervalo em campos diferentes
Web
import { query, where } from "firebase/firestore"; const q = query(citiesRef, where("state", ">=", "CA"), where("population", ">", 100000));
Web
citiesRef.where("state", ">=", "CA").where("population", ">", 100000);
Swift
citiesRef .whereField("state", isGreaterThanOrEqualTo: "CA") .whereField("population", isGreaterThan: 1000000)
Objective-C
[[citiesRef queryWhereField:@"state" isGreaterThanOrEqualTo:@"CA"] queryWhereField:@"population" isGreaterThan:@1000000];
Kotlin+KTX
citiesRef.whereGreaterThanOrEqualTo("state", "CA") .whereGreaterThan("population", 100000)
Java
citiesRef.whereGreaterThanOrEqualTo("state", "CA").whereGreaterThan("population", 100000);
Dart
final citiesRef = db.collection("cities"); citiesRef .where("state", isGreaterThanOrEqualTo: "CA") .where("population", isGreaterThan: 1000000);
Java
Python
Python
C++
// BAD EXAMPLE -- will crash the program: cities_ref.WhereGreaterThanOrEqualTo("state", FieldValue::String("CA")) .WhereGreaterThan("population", FieldValue::Integer(100000));
Node.js
Go
PHP
Unity
Query invalidRangeQuery = citiesRef .WhereGreaterThanOrEqualTo("State", "CA") .WhereGreaterThan("Population", 1000000);
C#
Ruby
OR
consultas
É possível combinar restrições com um OR
lógico. Exemplo:
Web
const q = query(citiesRef, or(where('capital', '==', true), where('population', '>=', 1000000) ) );
Web
Indisponível.
Swift
let query = db.collection("cities").whereFilter(Filter.orFilter([ Filter.whereField("capital", isEqualTo: true), Filter.whereField("population", isGreaterThanOrEqualTo: 1000000); ]))
Objective-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) ));
Java
Snippet indisponível
Python
Python
Snippet indisponível
C++
Snippet indisponível
Node.js
const bigCities = await citiesRef .where( Filter.or( Filter.where('capital', '==', true), Filter.where('population', '>=', 1000000) ) ) .get();
Go
PHP
Snippet indisponível
Unity
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#
Snippet indisponível
Ruby
Snippet indisponível
O Cloud Firestore usa índices compostos para exibir consultas OR
. Se
os índices não forem compatíveis com a consulta, o Cloud Firestore
vai sugerir índices adicionais para seu banco de dados.
É possível combinar consultas OR
com consultas compostas para filtrar combinações
de operações OR
e AND
. Exemplo:
Web
const q = query(collection(db, "cities"), and( where('state', '==', 'CA'), or( where('capital', '==', true), where('population', '>=', 1000000) ) ));
Web
Indisponível.
Swift
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); ]) ]))
Objective-C
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] ]] ]]];
Kotlin+KTX
val query = collection.where(Filter.and( Filter.equalTo("state", "CA"), Filter.or( Filter.equalTo("capital", true), Filter.greaterThanOrEqualTo("population", 1000000) ) ))
Java
Query query = collection.where(Filter.and( Filter.equalTo("state", "CA"), Filter.or( Filter.equalTo("capital", true), Filter.greaterThanOrEqualTo("population", 1000000) ) ));
Dart
var query = db.collection("cities") .where( Filter.and( Filter("state", isEqualTo: "CA"), Filter.or( Filter("capital", isEqualTo: true), Filter("population", isGreaterThan: 1000000) )));
Java
Snippet indisponível
Python
Snippet indisponível
Python
Snippet indisponível
C++
Snippet indisponível
Node.js
const bigCitiesInCalifornia = await citiesRef .where('state', '==', 'CA') .where( Filter.or( Filter.where('capital', '==', true), Filter.where('population', '>=', 1000000) ) ) .get();
Go
Snippet indisponível
PHP
Snippet indisponível
Unity
Query query = citiesRef.Where(Filter.And( Filter.EqualTo("state", "CA"), Filter.Or( Filter.EqualTo("capital", true), Filter.GreaterThanOrEqualTo("population", 1000000) ) ));
C#
Snippet indisponível
Ruby
Snippet indisponível
Limitações
Observe as seguintes limitações para as consultas or
:
- O Cloud Firestore limita uma consulta a um máximo de 30 perturbações com base no formato normal disjuntivo da consulta.
É mais provável que você atinja esse limite ao executar um
AND
de vários gruposOR
. - Não é possível combinar
not-in
comin
,array-contains-any
ouor
na mesma consulta.
Para uma descrição completa das limitações, consulte Limitações de consulta.
Consultas do grupo de coleções
Um grupo de coleções é composto de todas as coleções com o mesmo ID. Por padrão, por meio das consultas são recuperados resultados de uma única coleção no seu banco de dados. Use uma consulta de grupo de coleções para recuperar documentos de um grupo em vez de uma única coleção.
Por exemplo, é possível criar um grupo de coleções de landmarks
com a adição de uma subcoleção
de pontos de referência a cada cidade:
Web
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' }) ]);
Web
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' }) ]);
Swift
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)
Objective-C
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];
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)
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);
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);
Java
Python
Python
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
Go
PHP
Unity
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#
Ruby
Podemos usar a consulta simples e a composta descritas anteriormente para consultar
a subcoleção landmarks
de uma cidade, mas também é possível recuperar
os resultados da subcoleção landmarks
de todas as cidades ao mesmo tempo.
No grupo de coleções landmarks
estão todas as coleções com o ID landmarks
. Para consultá-lo, basta fazer uma consulta de grupo de coleções. Por exemplo,
com esta consulta de grupo de coleções são recuperados todos os pontos de referência museum
em todas as cidades:
Web
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()); });
Web
var museums = db.collectionGroup('landmarks').where('type', '==', 'museum'); museums.get().then((querySnapshot) => { querySnapshot.forEach((doc) => { console.log(doc.id, ' => ', doc.data()); }); });
Swift
db.collectionGroup("landmarks").whereField("type", isEqualTo: "museum").getDocuments { (snapshot, error) in // ... }
Objective-C
[[[self.db collectionGroupWithID:@"landmarks"] queryWhereField:@"type" isEqualTo:@"museum"] getDocumentsWithCompletion:^(FIRQuerySnapshot *snapshot, NSError *error) { // ... }];
Kotlin+KTX
db.collectionGroup("landmarks").whereEqualTo("type", "museum").get() .addOnSuccessListener { queryDocumentSnapshots -> // ... }
Java
db.collectionGroup("landmarks").whereEqualTo("type", "museum").get() .addOnSuccessListener(new OnSuccessListener<QuerySnapshot>() { @Override public void onSuccess(QuerySnapshot queryDocumentSnapshots) { // ... } });
Dart
db .collectionGroup("landmarks") .where("type", isEqualTo: "museum") .get() .then( (res) => print("Successfully completed"), onError: (e) => print("Error completing: $e"), );
Java
Python
Python
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
Go
PHP
Unity
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#
Ruby
Antes de usar uma consulta de grupo de coleções, é preciso criar um índice compatível com ela. Faça isso usando uma mensagem de erro, do console ou da CLI do Firebase.
No caso de SDKs da Web e para dispositivos móveis, você também precisa criar regras que permitam consultas de grupos de coleções.
Explicar o desempenho da sua consulta
O Cloud Firestore permite medir o desempenho das consultas no back-end e receber estatísticas detalhadas de desempenho sobre a execução de consultas de back-end em troca.
Os resultados do Query Explain ajudam a entender como suas consultas são executadas, mostrando ineficiências e o local de prováveis gargalos do lado do servidor.
Para mais informações, consulte o guia sobre Query Explain.
Limitações de consulta
Na lista a seguir, resumimos as limitações de consultas do Cloud Firestore:
- O Cloud Firestore é compatível com consultas lógicas
OR
por meio dos operadoresor
,in
earray-contains-any
. Essas consultas são limitadas a 30 disjunções com base no formulário normal disjuntivo da consulta. - É possível usar no máximo uma cláusula
array-contains
por disjunção (grupoor
). Não é possível combinararray-contains
comarray-contains-any
na mesma disjunção. - Não é possível combinar
not-in
comin
,array-contains-any
ouor
na mesma consulta. - Só é permitido um único
not-in
ou!=
por consulta. not-in
aceita até 10 valores de comparação.- A soma de filtros, ordens de classificação e caminho do documento pai (1 para uma subcoleção, 0 para uma coleção raiz) em uma consulta não pode exceder 100. Isso é calculado com base na forma normal disjuntiva da consulta.
- Uma consulta com um filtro de desigualdade em um campo implica ordenação por esse campo e filtra para a existência desse campo.
Limites de consultas OR
Para evitar que uma consulta se torne muito cara em termos computacionais,
o Cloud Firestore limita quantas cláusulas AND
e OR
podem ser combinadas.
Para aplicar esse limite, o Cloud Firestore converte consultas que executam um OR
lógico (or
, in
e array-contains-any
) para a
forma normal disjuntiva
(também conhecida como um OR
de AND
s). O Cloud Firestore limita uma consulta a
um máximo de 30 disjunções em forma normal disjuntiva.
Forma normal disjuntiva
O Cloud Firestore converte consultas em forma normal disjuntiva aplicando duas regras:
Flatten
Condições
A
,B
eC
:A and (B and C) => A and B and C
-
Condições
A
,B
,C
eD
: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)
Ao aplicar essas regras às consultas in
e array-contains-any
, lembre-se
de que esses operadores são abreviações de OR
. Por exemplo, a in [1,2]
é
uma forma abreviada de a = 1 OR a = 2
.
Os exemplos a seguir mostram o número de disjunções de consultas diferentes:
Consulta | Número de disjunções |
---|---|
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 A forma normal disjuntiva dessa consulta é igual à consulta acima. |
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 Essa consulta retorna um erro porque ultrapassa o limite de 30 disjunções. |
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
e existência
Quando você ordena uma consulta por um determinado campo, ela só pode retornar os documentos em que o campo de ordenação existe.
Por exemplo, a consulta a seguir não retornaria nenhum documento em que o campo
population
não estivesse definido, mesmo que atendesse aos filtros de consulta.
Java
db.collection("cities").whereEqualTo("country", “USA”).orderBy(“population”);
Um efeito relacionado se aplica a desigualdades. Uma consulta com um filtro de desigualdade
em um campo também implica ordenação por esse campo. A consulta
a seguir não retorna documentos sem um campo population
, mesmo que
country = USA
nesse documento. Como solução alternativa, você pode executar
consultas separadas para cada ordem ou atribuir um valor para todos os campos
que ordena.
Java
db.collection(“cities”).where(or(“country”, USA”), greaterThan(“population”, 250000));
A consulta acima inclui uma ordenação implícita sobre a desigualdade e é equivalente ao seguinte:
Java
db.collection(“cities”).where(or(“country”, USA”), greaterThan(“population”, 250000)).orderBy(“population”);
A seguir
- Saiba como ordenar e limitar dados nos resultados da consulta.
- Salve leituras quando quiser apenas contar os resultados.