ক্লাউড ফায়ারস্টোরে সহজ এবং যৌগিক প্রশ্নগুলি সম্পাদন করুন৷

Cloud Firestore আপনি একটি সংগ্রহ বা সংগ্রহ গোষ্ঠী থেকে কোন নথিগুলি পুনরুদ্ধার করতে চান তা নির্দিষ্ট করার জন্য শক্তিশালী ক্যোয়ারী কার্যকারিতা প্রদান করে৷ এই প্রশ্নগুলি get() বা addSnapshotListener() এর সাথেও ব্যবহার করা যেতে পারে, যেমন Get Data এবং Get Realtime Updates- এ বর্ণনা করা হয়েছে।

উদাহরণ ডেটা

শুরু করতে, শহরগুলি সম্পর্কে কিছু ডেটা লিখুন যাতে আমরা এটিকে আবার পড়ার বিভিন্ন উপায় দেখতে পারি:

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"] });
example_data.js

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"] });
test.firestore.js
সুইফট
দ্রষ্টব্য: এই পণ্যটি watchOS এবং অ্যাপ ক্লিপ লক্ষ্যে উপলব্ধ নয়। 
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
উদ্দেশ্য-C
দ্রষ্টব্য: এই পণ্যটি watchOS এবং অ্যাপ ক্লিপ লক্ষ্যে উপলব্ধ নয়। 
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 

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
জাভা 
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
পাইথন 
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
সি++ 
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
যাও 
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
পিএইচপি 
$citiesRef = $db->collection('samples/php/cities');
$citiesRef->document('SF')->set([
    'name' => 'San Francisco',
    'state' => 'CA',
    'country' => 'USA',
    'capital' => false,
    'population' => 860000,
    'density' => 18000,
    'regions' => ['west_coast', 'norcal']
]);
$citiesRef->document('LA')->set([
    'name' => 'Los Angeles',
    'state' => 'CA',
    'country' => 'USA',
    'capital' => false,
    'population' => 3900000,
    'density' => 8000,
    'regions' => ['west_coast', 'socal']
]);
$citiesRef->document('DC')->set([
    'name' => 'Washington D.C.',
    'state' => null,
    'country' => 'USA',
    'capital' => true,
    'population' => 680000,
    'density' => 11000,
    'regions' => ['east_coast']
]);
$citiesRef->document('TOK')->set([
    'name' => 'Tokyo',
    'state' => null,
    'country' => 'Japan',
    'capital' => true,
    'population' => 9000000,
    'density' => 16000,
    'regions' => ['kanto', 'honshu']
]);
$citiesRef->document('BJ')->set([
    'name' => 'Beijing',
    'state' => null,
    'country' => 'China',
    'capital' => true,
    'population' => 21500000,
    'density' => 3500,
    'regions' => ['jingjinji', 'hebei']
]);
printf('Added example cities data to the cities collection.' . PHP_EOL);
query_filter_dataset.php
ঐক্য 
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"} }
});
সি# 
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 },
    { "Density", 18000 },
    { "Regions", new[] {"west_coast", "norcal"} }
});
await citiesRef.Document("LA").SetAsync(new Dictionary<string, object>
{
    { "Name", "Los Angeles" },
    { "State", "CA" },
    { "Country", "USA" },
    { "Capital", false },
    { "Population", 3900000 },
    { "Density", 8300 },
    { "Regions", new[] {"west_coast", "socal"} }
});
await citiesRef.Document("DC").SetAsync(new Dictionary<string, object>
{
    { "Name", "Washington D.C." },
    { "State", null },
    { "Country", "USA" },
    { "Capital", true },
    { "Population", 680000 },
    { "Density", 11300 },
    { "Regions", new[] {"east_coast"} }
});
await citiesRef.Document("TOK").SetAsync(new Dictionary<string, object>
{
    { "Name", "Tokyo" },
    { "State", null },
    { "Country", "Japan" },
    { "Capital", true },
    { "Population", 9000000 },
    { "Density", 16000 },
    { "Regions", new[] {"kanto", "honshu"} }
});
await citiesRef.Document("BJ").SetAsync(new Dictionary<string, object>
{
    { "Name", "Beijing" },
    { "State", null },
    { "Country", "China" },
    { "Capital", true },
    { "Population", 21500000 },
    { "Density", 3500 },
    { "Regions", new[] {"jingjinji", "hebei"} }
});
Console.WriteLine("Added example cities data to the cities collection.");
Program.cs
রুবি 
cities_ref = firestore.col collection_path
cities_ref.doc("SF").set(
  {
    name:       "San Francisco",
    state:      "CA",
    country:    "USA",
    capital:    false,
    density:    18_000,
    population: 860_000,
    regions:    ["west_coast", "norcal"]
  }
)
cities_ref.doc("LA").set(
  {
    name:       "Los Angeles",
    state:      "CA",
    country:    "USA",
    capital:    false,
    density:    8_300,
    population: 3_900_000,
    regions:    ["west_coast", "socal"]
  }
)
cities_ref.doc("DC").set(
  {
    name:       "Washington D.C.",
    state:      nil,
    country:    "USA",
    capital:    true,
    density:    11_300,
    population: 680_000,
    regions:    ["east_coast"]
  }
)
cities_ref.doc("TOK").set(
  {
    name:       "Tokyo",
    state:      nil,
    country:    "Japan",
    capital:    true,
    density:    16_000,
    population: 9_000_000,
    regions:    ["kanto", "honshu"]
  }
)
cities_ref.doc("BJ").set(
  {
    name:       "Beijing",
    state:      nil,
    country:    "China",
    capital:    true,
    density:    3_500,
    population: 21_500_000,
    regions:    ["jingjinji", "hebei"]
  }
)
query_data.rb

সহজ প্রশ্ন

নিম্নলিখিত ক্যোয়ারী রাজ্য CA সহ সমস্ত শহর ফেরত দেয়:

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"));
simple_queries.js

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");
test.firestore.js
সুইফট
দ্রষ্টব্য: এই পণ্যটি watchOS এবং অ্যাপ ক্লিপ লক্ষ্যে উপলব্ধ নয়। 
// 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
উদ্দেশ্য-C
দ্রষ্টব্য: এই পণ্যটি watchOS এবং অ্যাপ ক্লিপ লক্ষ্যে উপলব্ধ নয়। 
// 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 

// 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
জাভা 
// 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
পাইথন 
# 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
সি++ 
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
যাও 
query := client.Collection("cities").Where("state", "==", "CA")
query.go
পিএইচপি 
$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
ঐক্য 
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));
    } 
});
সি# 
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
রুবি 
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

নিম্নলিখিত ক্যোয়ারী সমস্ত রাজধানী শহর ফেরত দেয়:

Web 

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

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

Web

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

var query = citiesRef.where("capital", "==", true);
test.firestore.js
সুইফট
দ্রষ্টব্য: এই পণ্যটি watchOS এবং অ্যাপ ক্লিপ লক্ষ্যে উপলব্ধ নয়। 
let capitalCities = db.collection("cities").whereField("capital", isEqualTo: true)
ViewController.swift
উদ্দেশ্য-C
দ্রষ্টব্য: এই পণ্যটি watchOS এবং অ্যাপ ক্লিপ লক্ষ্যে উপলব্ধ নয়। 
FIRQuery *capitalCities =
    [[self.db collectionWithPath:@"cities"] queryWhereField:@"capital" isEqualTo:@YES];
ViewController.m

Kotlin 

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
জাভা 
// 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
পাইথন 
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
সি++ 
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
যাও 
query := client.Collection("cities").Where("capital", "==", true)
query.go
পিএইচপি 
$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
ঐক্য 
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));
    } 
});
সি# 
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
রুবি 
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

একটি প্রশ্ন চালান

একটি ক্যোয়ারী অবজেক্ট তৈরি করার পরে, ফলাফলগুলি পুনরুদ্ধার করতে get() ফাংশনটি ব্যবহার করুন:

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());
});
get_multiple.js

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);
    });
test.firestore.js
সুইফট
দ্রষ্টব্য: এই পণ্যটি watchOS এবং অ্যাপ ক্লিপ লক্ষ্যে উপলব্ধ নয়। 
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
উদ্দেশ্য-C
দ্রষ্টব্য: এই পণ্যটি watchOS এবং অ্যাপ ক্লিপ লক্ষ্যে উপলব্ধ নয়। 
[[[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 

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
জাভা 
// 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
পাইথন 
# 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
সি++ 
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
যাও 

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
পিএইচপি

পিএইচপি

একটি Cloud Firestore ক্লায়েন্ট ইনস্টল এবং তৈরি করার বিষয়ে আরও জানতে, Cloud Firestore ক্লায়েন্ট লাইব্রেরি দেখুন। 

$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
ঐক্য 
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("");
  };
});
সি# 
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
রুবি 
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

ক্যোয়ারী ফলাফল পুনরুদ্ধার সম্পর্কে আরও তথ্যের জন্য ডেটা পান দেখুন। আপনি বর্তমান ফলাফল পেতে এবং ভবিষ্যতের আপডেটগুলি শুনতে একটি প্রশ্নের সাথে একজন শ্রোতাকে যুক্ত করতে পারেন৷

ক্যোয়ারী অপারেটর

where() পদ্ধতিতে তিনটি প্যারামিটার লাগে: ফিল্টার করার জন্য একটি ক্ষেত্র, একটি তুলনা অপারেটর এবং একটি মান। Cloud Firestore নিম্নলিখিত তুলনা অপারেটরগুলিকে সমর্থন করে:

যেমন:

Web 

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

const stateQuery = citiesRef.where("state", "==", "CA");
const populationQuery = citiesRef.where("population", "<", 100000);
const nameQuery = citiesRef.where("name", ">=", "San Francisco");
test.firestore.js
সুইফট
দ্রষ্টব্য: এই পণ্যটি watchOS এবং অ্যাপ ক্লিপ লক্ষ্যে উপলব্ধ নয়। 
let stateQuery = citiesRef.whereField("state", isEqualTo: "CA")
let populationQuery = citiesRef.whereField("population", isLessThan: 100000)
let nameQuery = citiesRef.whereField("name", isGreaterThanOrEqualTo: "San Francisco")
ViewController.swift
উদ্দেশ্য-C
দ্রষ্টব্য: এই পণ্যটি watchOS এবং অ্যাপ ক্লিপ লক্ষ্যে উপলব্ধ নয়। 
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 

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
জাভা 
Query stateQuery = cities.whereEqualTo("state", "CA");
Query populationQuery = cities.whereLessThan("population", 1000000L);
Query nameQuery = cities.whereGreaterThanOrEqualTo("name", "San Francisco");
QueryDataSnippets.java
পাইথন 
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
সি++ 
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
যাও 
countryQuery := cities.Where("state", "==", "CA")
popQuery := cities.Where("population", "<", 1000000)
cityQuery := cities.Where("name", ">=", "San Francisco")
query.go
পিএইচপি 
$stateQuery = $citiesRef->where('state', '=', 'CA');
$populationQuery = $citiesRef->where('population', '>', 1000000);
$nameQuery = $citiesRef->where('name', '>=', 'San Francisco');
query_filter_single_examples.php
ঐক্য 
Query stateQuery = citiesRef.WhereEqualTo("State", "CA");
Query populationQuery = citiesRef.WhereGreaterThan("Population", 1000000);
Query nameQuery = citiesRef.WhereGreaterThanOrEqualTo("Name", "San Francisco");
সি# 
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
রুবি 
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

সমান নয় ( != )

নট ইকুয়াল ( != ) অপারেটর ব্যবহার করুন যেখানে প্রদত্ত ক্ষেত্রটি বিদ্যমান রয়েছে এবং তুলনা মানের সাথে মেলে না। যেমন:

Web 

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

Web

citiesRef.where("capital", "!=", false);
test.firestore.js
সুইফট
দ্রষ্টব্য: এই পণ্যটি watchOS এবং অ্যাপ ক্লিপ লক্ষ্যে উপলব্ধ নয়। 
let notEqualQuery = citiesRef.whereField("capital", isNotEqualTo: false)
ViewController.swift
উদ্দেশ্য-C
দ্রষ্টব্য: এই পণ্যটি watchOS এবং অ্যাপ ক্লিপ লক্ষ্যে উপলব্ধ নয়। 
query = [citiesRef queryWhereField:@"capital" isNotEqualTo:@NO];
ViewController.m

Kotlin 

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

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

এই ক্যোয়ারীটি প্রতিটি city নথি প্রদান করে যেখানে capital ফিল্ডটি false বা null ছাড়া অন্য একটি মান সহ বিদ্যমান। এটি city নথিগুলি অন্তর্ভুক্ত করে যেখানে capital ক্ষেত্র মান true বা null ব্যতীত অন্য কোনো নন-বুলিয়ান মানের সমান।

এই প্রশ্নটি city নথিগুলি ফেরত দেয় না যেখানে capital ক্ষেত্রটি বিদ্যমান নেই৷ নট-ইকুয়াল ( != ) এবং not-in কোয়েরি নথিগুলিকে বাদ দেয় যেখানে প্রদত্ত ক্ষেত্রটি বিদ্যমান নেই ।

একটি ক্ষেত্র বিদ্যমান থাকে যখন এটি একটি খালি স্ট্রিং ( "" ), null , এবং NaN (কোন সংখ্যা নয়) সহ যেকোনো মানতে সেট করা থাকে। মনে রাখবেন যে null ফিল্ডের মান মেলে না != ক্লজ, কারণ x != null মূল্যায়ন করে undefined .

সীমাবদ্ধতা

!= প্রশ্নগুলির জন্য নিম্নলিখিত সীমাবদ্ধতাগুলি নোট করুন:

  • শুধুমাত্র নথি যেখানে প্রদত্ত ক্ষেত্র বিদ্যমান আছে ক্যোয়ারী মেলে.
  • আপনি একটি যৌগিক প্রশ্নে not-in এবং != একত্রিত করতে পারবেন না।

অ্যারে সদস্যপদ

আপনি অ্যারের মানগুলির উপর ভিত্তি করে ফিল্টার করতে array-contains অপারেটর ব্যবহার করতে পারেন। যেমন:

Web 

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

Web

citiesRef.where("regions", "array-contains", "west_coast");
test.firestore.js
সুইফট
দ্রষ্টব্য: এই পণ্যটি watchOS এবং অ্যাপ ক্লিপ লক্ষ্যে উপলব্ধ নয়। 
citiesRef
  .whereField("regions", arrayContains: "west_coast")
ViewController.swift
উদ্দেশ্য-C
দ্রষ্টব্য: এই পণ্যটি watchOS এবং অ্যাপ ক্লিপ লক্ষ্যে উপলব্ধ নয়। 
[citiesRef queryWhereField:@"state" arrayContains:@"west_coast"];
ViewController.m

Kotlin 

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
জাভা 
CollectionReference citiesRef = db.collection("cities");
Query westCoastQuery = citiesRef.whereArrayContains("regions", "west_coast");
QueryDataSnippets.java
পাইথন 
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
সি++ 
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
যাও 
query := cities.Where("regions", "array-contains", "west_coast").Documents(ctx)
query.go
পিএইচপি 
$containsQuery = $citiesRef->where('regions', 'array-contains', 'west_coast');
query_filter_array_contains.php
ঐক্য 
CollectionReference citiesRef = db.Collection("cities");
Query arrayContainsQuery = citiesRef.WhereArrayContains("region", "west_coast");
সি# 
CollectionReference citiesRef = db.Collection("cities");
Query query = citiesRef.WhereArrayContains("Regions", "west_coast");
Program.cs
রুবি 
cities_ref = firestore.col collection_path
cities = cities_ref.where "regions", "array-contains", "west_coast"
query_data.rb

এই ক্যোয়ারীটি প্রতিটি city নথি প্রদান করে যেখানে regions ক্ষেত্রটি একটি অ্যারে যা west_coast ধারণ করে। যদি অ্যারেতে আপনি যে মানের প্রশ্ন করেন তার একাধিক দৃষ্টান্ত থাকে, তাহলে নথিটি শুধুমাত্র একবার ফলাফলে অন্তর্ভুক্ত করা হয়।

আপনি সর্বাধিক একটি array-contains ব্যবহার করতে পারেন- প্রতি বিচ্ছিন্নতা ( or গোষ্ঠী) ধারা রয়েছে। আপনি একই বিচ্ছিন্নতার মধ্যে array-contains এর সাথে array-contains-any একত্রিত করতে পারবেন না।

in , not-in , এবং array-contains-any

লজিক্যাল OR সাথে একই ক্ষেত্রে 30টি পর্যন্ত সমতা ( == ) ক্লজ একত্রিত করতে in অপারেটর ব্যবহার করুন। একটি in কোয়েরি নথি প্রদান করে যেখানে প্রদত্ত ক্ষেত্রটি তুলনামূলক মানগুলির সাথে মেলে। যেমন:

Web 

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

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

Web

citiesRef.where('country', 'in', ['USA', 'Japan']);
test.firestore.js
সুইফট
দ্রষ্টব্য: এই পণ্যটি watchOS এবং অ্যাপ ক্লিপ লক্ষ্যে উপলব্ধ নয়। 
let citiesRef = db.collection("cities")

citiesRef.whereField("country", in: ["USA", "Japan"])
ViewController.swift
উদ্দেশ্য-C
দ্রষ্টব্য: এই পণ্যটি watchOS এবং অ্যাপ ক্লিপ লক্ষ্যে উপলব্ধ নয়। 
FIRCollectionReference *citiesRef = [self.db collectionWithPath:@"cities"];

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

Kotlin 

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

Query query = citiesRef.whereIn("country", Arrays.asList("USA", "Japan"));
QueryDataSnippets.java
পাইথন 
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
সি++ 
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
যাও 
cities := client.Collection("cities")
query := cities.Where("country", "in", []string{"USA", "Japan"}).Documents(ctx)
query.go
পিএইচপি 
$rangeQuery = $citiesRef->where('country', 'in', ['USA', 'Japan']);
query_filter_in.php
ঐক্য 
CollectionReference citiesRef = db.Collection("cities");
List countriesList = new List<object>() {"USA", "Japan"};

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

এই প্রশ্নটি প্রতিটি city নথি প্রদান করে যেখানে country ক্ষেত্রটি USA বা Japan সেট করা আছে। উদাহরণের ডেটা থেকে, এতে SF , LA , DC , এবং TOK নথি অন্তর্ভুক্ত রয়েছে৷

not-in

লজিক্যাল AND সাথে একই ক্ষেত্রে 10টি সমান ( != ) ক্লজ একত্রিত করতে not-in অপারেটর ব্যবহার করুন। একটি not-in ক্যোয়ারী নথি প্রদান করে যেখানে প্রদত্ত ক্ষেত্রটি বিদ্যমান, null নয় এবং তুলনামূলক মানের কোনোটির সাথে মেলে না। যেমন:

Web 

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

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

Web

citiesRef.where('country', 'not-in', ['USA', 'Japan']);
test.firestore.js
সুইফট
দ্রষ্টব্য: এই পণ্যটি watchOS এবং অ্যাপ ক্লিপ লক্ষ্যে উপলব্ধ নয়। 
citiesRef.whereField("country", notIn: ["USA", "Japan"])
ViewController.swift
উদ্দেশ্য-C
দ্রষ্টব্য: এই পণ্যটি watchOS এবং অ্যাপ ক্লিপ লক্ষ্যে উপলব্ধ নয়। 
[citiesRef queryWhereField:@"country" notIn:@[@"USA", @"Japan"]];
ViewController.m

Kotlin 

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

Query query = citiesRef.whereNotIn("country", Arrays.asList("USA", "Japan"));
QueryDataSnippets.java
পাইথন 
// Snippet not yet available
সি++ 
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
যাও 
// Snippet not yet available
পিএইচপি 
$stateQuery = $citiesRef->where(
    'country',
    \Google\Cloud\Firestore\V1\StructuredQuery\FieldFilter\Operator::NOT_IN,
    ['USA', 'Japan']
);
query_filter_not_in.php
ঐক্য 
Query query = citiesRef.WhereNotIn(new FieldPath("country"), new List<string>{"USA", "Japan"});
Query query = citiesRef.WhereNotIn("country", new List<object>(){"USA", "Japan"});
সি# 
// Snippet not yet available
রুবি 
cities_ref = firestore.col collection_path
usr_or_japan = cities_ref.where "country", "not_in", ["USA", "Japan"]
query_data.rb

এই ক্যোয়ারীটি প্রতিটি city নথি প্রদান করে যেখানে country ক্ষেত্রটি বিদ্যমান এবং USA , Japan , বা null সেট করা নেই। উদাহরণের তথ্য থেকে, এতে London এবং Hong Kong নথি অন্তর্ভুক্ত রয়েছে।

not-in কোয়েরি নথিগুলিকে বাদ দেয় যেখানে প্রদত্ত ক্ষেত্রটি বিদ্যমান নেই। একটি ক্ষেত্র বিদ্যমান থাকে যখন এটি একটি খালি স্ট্রিং ( "" ), null , এবং NaN (কোন সংখ্যা নয়) সহ যেকোনো মানতে সেট করা থাকে। উল্লেখ্য যে x != null মূল্যায়ন করে undefined . তুলনামূলক মানগুলির মধ্যে একটি হিসাবে null সহ একটি not-in কোয়েরি কোনো নথির সাথে মেলে না।

array-contains-any

একটি লজিক্যাল OR সাথে একই ক্ষেত্রে 30টি পর্যন্ত array-contains ধারাগুলিকে একত্রিত করতে array-contains-any অপারেটর ব্যবহার করুন। একটি array-contains-any কোয়েরি নথি প্রদান করে যেখানে প্রদত্ত ক্ষেত্রটি একটি অ্যারে যা এক বা একাধিক তুলনা মান ধারণ করে:

Web 

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

citiesRef.where('regions', 'array-contains-any',
    ['west_coast', 'east_coast']);
test.firestore.js
সুইফট
দ্রষ্টব্য: এই পণ্যটি watchOS এবং অ্যাপ ক্লিপ লক্ষ্যে উপলব্ধ নয়। 
let citiesRef = db.collection("cities")
citiesRef.whereField("regions", arrayContainsAny: ["west_coast", "east_coast"])
ViewController.swift
উদ্দেশ্য-C
দ্রষ্টব্য: এই পণ্যটি watchOS এবং অ্যাপ ক্লিপ লক্ষ্যে উপলব্ধ নয়। 
FIRCollectionReference *citiesRef = [self.db collectionWithPath:@"cities"];

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

Kotlin 

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

Query query =
    citiesRef.whereArrayContainsAny("regions", Arrays.asList("west_coast", "east_coast"));
QueryDataSnippets.java
পাইথন 
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
সি++ 
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
যাও 
cities := client.Collection("cities")
query := cities.Where("regions", "array-contains-any", []string{"west_coast", "east_coast"}).Documents(ctx)
query.go
পিএইচপি 
$containsQuery = $citiesRef->where('regions', 'array-contains-any', ['west_coast', 'east_coast']);
query_filter_array_contains_any.php
ঐক্য 
Query query = citiesRef.WhereArrayContainsAny(
                         "regions",
                         new List<object>()
                         {
                            new List<object>(){"west_coast"},
                            new List<object>(){"east_coast"}});
সি# 
CollectionReference citiesRef = db.Collection("cities");
Query query = citiesRef.WhereArrayContainsAny("Regions", new[] { "west_coast", "east_coast" });
Program.cs
রুবি 
cities_ref = firestore.col collection_path
costal_cities = cities_ref.where "regions", "array-contains-any", ["west_coast", "east_coast"]
query_data.rb

এই ক্যোয়ারীটি প্রতিটি শহরের নথি প্রদান করে যেখানে regions ক্ষেত্রটি একটি অ্যারে যা west_coast বা east_coast ধারণ করে। উদাহরণের ডেটা থেকে, এতে SF , LA , এবং DC নথি অন্তর্ভুক্ত রয়েছে৷

array-contains-any এর ফলাফল ডি-ডুপ করা হয়। এমনকি যদি একটি নথির অ্যারে ক্ষেত্র তুলনামূলক মানগুলির একটির বেশি মেলে, ফলাফল সেটে সেই নথিটি শুধুমাত্র একবারই অন্তর্ভুক্ত থাকে।

array-contains-any সবসময় অ্যারের ডেটা টাইপ দ্বারা ফিল্টার করে। উদাহরণস্বরূপ, উপরের ক্যোয়ারীটি একটি শহরের নথি প্রদান করবে না যেখানে একটি অ্যারের পরিবর্তে, regions ক্ষেত্রটি স্ট্রিং west_coast ।

আপনি in একটি তুলনা মান হিসাবে একটি অ্যারে মান ব্যবহার করতে পারেন, কিন্তু array-contains-any বিপরীতে, ধারাটি অ্যারের দৈর্ঘ্য, ক্রম এবং মানগুলির সঠিক মিলের জন্য মেলে। যেমন:

Web 

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

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

Web

citiesRef.where('regions', 'in',
    [['west_coast'], ['east_coast']]);
test.firestore.js
সুইফট
দ্রষ্টব্য: এই পণ্যটি watchOS এবং অ্যাপ ক্লিপ লক্ষ্যে উপলব্ধ নয়। 
citiesRef.whereField("regions", in: [["west_coast"], ["east_coast"]])
ViewController.swift
উদ্দেশ্য-C
দ্রষ্টব্য: এই পণ্যটি watchOS এবং অ্যাপ ক্লিপ লক্ষ্যে উপলব্ধ নয়। 
[citiesRef queryWhereField:@"regions" in:@[@[@"west_coast"], @[@"east_coast"]]];
ViewController.m

Kotlin 

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

Query query =
    citiesRef.whereIn(
        "regions", Arrays.asList(Arrays.asList("west_coast"), Arrays.asList("east_coast")));
QueryDataSnippets.java
পাইথন 
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
সি++ 
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
যাও 
cities := client.Collection("cities")
query := cities.Where("regions", "in", [][]string{{"west_coast"}, {"east_coast"}}).Documents(ctx)
query.go
পিএইচপি 
$rangeQuery = $citiesRef->where('regions', 'in', [['west_coast'], ['east_coast']]);
query_filter_in_with_array.php
ঐক্য 
Query query = citiesRef.WhereIn(new FieldPath("regions"), new List<string>{"west_coast", "east_coast"});
সি# 
CollectionReference citiesRef = db.Collection("cities");
Query query = citiesRef.WhereIn("Regions",
    new[] { new[] { "west_coast" }, new[] { "east_coast" } });
Program.cs
রুবি 
cities_ref = firestore.col collection_path
exactly_one_cost = cities_ref.where "regions", "in", [["west_coast"], ["east_coast"]]
query_data.rb

এই ক্যোয়ারীটি প্রতিটি শহরের নথি প্রদান করে যেখানে regions ক্ষেত্রটি একটি অ্যারে যা west_coast বা east_coast ঠিক একটি উপাদান ধারণ করে। উদাহরণের তথ্য থেকে, শুধুমাত্র DC নথিটি তার ["east_coast"] regions ক্ষেত্রের সাথে যোগ্যতা অর্জন করে। SF নথিটি অবশ্য মেলে না কারণ এর regions ক্ষেত্র হল ["west_coast", "norcal"] ।

সীমাবদ্ধতা

in , not-in , এবং array-contains-any জন্য নিম্নলিখিত সীমাবদ্ধতাগুলি নোট করুন:

  • Cloud Firestore লজিক্যাল OR কোয়েরির জন্য or , in , এবং array-contains-any অপারেটরের মাধ্যমে সমর্থন প্রদান করে। এই ক্যোয়ারীগুলি ক্যোয়ারী এর ডিসজংক্টিভ নরমাল ফর্মের উপর ভিত্তি করে 30 টি ডিসজেকশনের মধ্যে সীমাবদ্ধ।
  • আপনি সর্বাধিক একটি array-contains ব্যবহার করতে পারেন- প্রতি বিচ্ছিন্নতা ( or গোষ্ঠী) ধারা রয়েছে। আপনি একই বিচ্ছিন্নতার মধ্যে array-contains এর সাথে array-contains-any একত্রিত করতে পারবেন না।
  • আপনি not-in সাথে not equals != সাথে একত্রিত করতে পারবেন না।
  • not-in 10টি পর্যন্ত তুলনা মান সমর্থন করে।

যৌগিক ( AND ) প্রশ্ন

আপনি একাধিক সমতা অপারেটর ( == বা array-contains ) চেইন করে একটি লজিক্যাল AND এর সাথে সীমাবদ্ধতাগুলি একত্রিত করতে পারেন। যাইহোক, অসমতা অপারেটর, < , <= , > , এবং != সাথে সমতা অপারেটরকে একত্রিত করতে আপনাকে অবশ্যই একটি যৌগিক সূচক তৈরি করতে হবে।

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));
chain_filters.js

Web

const q1 = citiesRef.where("state", "==", "CO").where("name", "==", "Denver");
const q2 = citiesRef.where("state", "==", "CA").where("population", "<", 1000000);
test.firestore.js
সুইফট
দ্রষ্টব্য: এই পণ্যটি watchOS এবং অ্যাপ ক্লিপ লক্ষ্যে উপলব্ধ নয়। 
citiesRef
  .whereField("state", isEqualTo: "CO")
  .whereField("name", isEqualTo: "Denver")
citiesRef
  .whereField("state", isEqualTo: "CA")
  .whereField("population", isLessThan: 1000000)
ViewController.swift
উদ্দেশ্য-C
দ্রষ্টব্য: এই পণ্যটি watchOS এবং অ্যাপ ক্লিপ লক্ষ্যে উপলব্ধ নয়। 
[[citiesRef queryWhereField:@"state" isEqualTo:@"CO"]
    queryWhereField:@"name" isGreaterThanOrEqualTo:@"Denver"];
[[citiesRef queryWhereField:@"state" isEqualTo:@"CA"]
    queryWhereField:@"population" isLessThan:@1000000];
ViewController.m

Kotlin 

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
জাভা 
Query chainedQuery1 = cities.whereEqualTo("state", "CO").whereEqualTo("name", "Denver");
QueryDataSnippets.java
পাইথন 
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
সি++ 
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
যাও 
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
পিএইচপি 
$chainedQuery = $citiesRef
    ->where('state', '=', 'CA')
    ->where('name', '=', 'San Francisco');
query_filter_compound_multi_eq.php
ঐক্য 
Query chainedQuery = citiesRef
    .WhereEqualTo("State", "CA")
    .WhereEqualTo("Name", "San Francisco");
সি# 
CollectionReference citiesRef = db.Collection("cities");
Query chainedQuery = citiesRef
    .WhereEqualTo("State", "CA")
    .WhereEqualTo("Name", "San Francisco");
Program.cs
রুবি 
chained_query = cities_ref.where("state", "=", "CA").where("name", "=", "San Francisco")
query_data.rb

OR প্রশ্ন

আপনি একটি লজিক্যাল OR সাথে সীমাবদ্ধতাগুলিকে একত্রিত করতে পারেন। যেমন:

Web 

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

Web

পাওয়া যায় না।

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

Kotlin 

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
জাভা

স্নিপেট উপলব্ধ নয়।

পাইথন 
from google.cloud.firestore_v1.base_query import FieldFilter, Or

col_ref = client.collection("cities")
# Execute the query
query = col_ref.where(
    filter=Or(
        [
            FieldFilter("capital", "==", True),
            FieldFilter("population", ">", 1_000_000),
        ]
    )
)
docs = query.stream()
query_filter_or.py

Python

স্নিপেট উপলব্ধ নয়।

সি++

স্নিপেট উপলব্ধ নয়।

Node.js 
const bigCities = await citiesRef
  .where(
    Filter.or(
      Filter.where('capital', '==', true),
      Filter.where('population', '>=', 1000000)
    )
  )
  .get();
index.js
যাও 
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
পিএইচপি

স্নিপেট উপলব্ধ নয়।

ঐক্য 
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));
    } 
});
সি#

স্নিপেট উপলব্ধ নয়।

রুবি

স্নিপেট উপলব্ধ নয়।

Cloud Firestore আপনার কম্পোজিট ইনডেক্স ব্যবহার করে OR কোয়েরি পরিবেশন করে। যদি আপনার সূচীগুলি ক্যোয়ারী সমর্থন না করে, তাহলে Cloud Firestore আপনার ডাটাবেসের জন্য অতিরিক্ত সূচী প্রস্তাব করে ৷

আপনি OR এবং AND ক্রিয়াকলাপগুলির সংমিশ্রণে ফিল্টার করতে যৌগিক প্রশ্নের সাথে OR প্রশ্নগুলিকে একত্রিত করতে পারেন। যেমন:

Web 

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

Web

পাওয়া যায় না।

সুইফট
দ্রষ্টব্য: এই পণ্যটি watchOS এবং অ্যাপ ক্লিপ লক্ষ্যে উপলব্ধ নয়। 
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
উদ্দেশ্য-C
দ্রষ্টব্য: এই পণ্যটি watchOS এবং অ্যাপ ক্লিপ লক্ষ্যে উপলব্ধ নয়। 
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 

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
জাভা

স্নিপেট উপলব্ধ নয়।

পাইথন

স্নিপেট উপলব্ধ নয়।

Python

স্নিপেট উপলব্ধ নয়।

সি++

স্নিপেট উপলব্ধ নয়।

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

স্নিপেট উপলব্ধ নয়।

পিএইচপি

স্নিপেট উপলব্ধ নয়।

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

স্নিপেট উপলব্ধ নয়।

রুবি

স্নিপেট উপলব্ধ নয়।

সীমাবদ্ধতা

নিম্নলিখিত সীমাবদ্ধতাগুলি or প্রশ্নের জন্য নোট করুন:

সীমাবদ্ধতার সম্পূর্ণ বিবরণের জন্য, ক্যোয়ারী সীমাবদ্ধতা দেখুন।

সংগ্রহ গ্রুপ প্রশ্ন

একটি সংগ্রহ গ্রুপ একই আইডি সহ সমস্ত সংগ্রহ নিয়ে গঠিত। ডিফল্টরূপে, প্রশ্নগুলি আপনার ডাটাবেসের একটি একক সংগ্রহ থেকে ফলাফল পুনরুদ্ধার করে। একক সংগ্রহের পরিবর্তে একটি সংগ্রহ গোষ্ঠী থেকে নথি পুনরুদ্ধার করতে একটি সংগ্রহ গোষ্ঠী ক্যোয়ারী ব্যবহার করুন৷

উদাহরণস্বরূপ, আপনি প্রতিটি শহরে একটি ল্যান্ডমার্ক সাব-কলেকশন যোগ করে একটি landmarks সংগ্রহ গ্রুপ তৈরি করতে পারেন:

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'
    })
]);
fs_collection_group_query_data_setup.js

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'
    })
]);
test.firestore.js
সুইফট
দ্রষ্টব্য: এই পণ্যটি watchOS এবং অ্যাপ ক্লিপ লক্ষ্যে উপলব্ধ নয়। 
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
উদ্দেশ্য-C
দ্রষ্টব্য: এই পণ্যটি watchOS এবং অ্যাপ ক্লিপ লক্ষ্যে উপলব্ধ নয়। 
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 

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
জাভা 
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
পাইথন 
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
সি++ 
// 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
যাও 
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
পিএইচপি 
$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
ঐক্য 
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;
সি# 
// 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 Google.Cloud.Firestore.Admin.V1;
using Google.Protobuf.WellKnownTypes;
using Grpc.Core;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Threading.Tasks;
using static Google.Cloud.Firestore.Admin.V1.Index.Types;

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
    subcollection-query
    chained-query
    composite-index-chained-query
    range-query
    multiple-inequalities
";
        private static async Task QueryCreateExamples(string project)
        {
            FirestoreDb db = FirestoreDb.Create(project);
            // Note: the extra braces here are just to allow multiple citiesRef local variables.
            {
                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 },
                    { "Density", 18000 },
                    { "Regions", new[] {"west_coast", "norcal"} }
                });
                await citiesRef.Document("LA").SetAsync(new Dictionary<string, object>
                {
                    { "Name", "Los Angeles" },
                    { "State", "CA" },
                    { "Country", "USA" },
                    { "Capital", false },
                    { "Population", 3900000 },
                    { "Density", 8300 },
                    { "Regions", new[] {"west_coast", "socal"} }
                });
                await citiesRef.Document("DC").SetAsync(new Dictionary<string, object>
                {
                    { "Name", "Washington D.C." },
                    { "State", null },
                    { "Country", "USA" },
                    { "Capital", true },
                    { "Population", 680000 },
                    { "Density", 11300 },
                    { "Regions", new[] {"east_coast"} }
                });
                await citiesRef.Document("TOK").SetAsync(new Dictionary<string, object>
                {
                    { "Name", "Tokyo" },
                    { "State", null },
                    { "Country", "Japan" },
                    { "Capital", true },
                    { "Population", 9000000 },
                    { "Density", 16000 },
                    { "Regions", new[] {"kanto", "honshu"} }
                });
                await citiesRef.Document("BJ").SetAsync(new Dictionary<string, object>
                {
                    { "Name", "Beijing" },
                    { "State", null },
                    { "Country", "China" },
                    { "Capital", true },
                    { "Population", 21500000 },
                    { "Density", 3500 },
                    { "Regions", new[] {"jingjinji", "hebei"} }
                });
                Console.WriteLine("Added example cities data to the cities collection.");
            }

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

        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);
            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 SubcollectionQuery(string project)
        {
            FirestoreDb db = FirestoreDb.Create(project);
            CollectionReference landmarks = db.Collection("cities").Document("SF").Collection("landmarks");
            QuerySnapshot querySnapshot = await landmarks.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 async Task MultipleInequalitiesQuery(string project)
        {
            FirestoreDb db = FirestoreDb.Create(project);
            FirestoreAdminClient adminClient = FirestoreAdminClient.Create();
            var index = new Google.Cloud.Firestore.Admin.V1.Index
            {
                Fields =
                {
                    new IndexField { FieldPath = "Density", Order = IndexField.Types.Order.Ascending },
                    new IndexField { FieldPath = "Population", Order = IndexField.Types.Order.Ascending }
                },
                QueryScope = QueryScope.Collection
            };

            // We speculatively try to create the index, and just ignore an error of it already existing.
            try
            {
                var lro = await adminClient.CreateIndexAsync(new CollectionGroupName(db.ProjectId, db.DatabaseId, "cities"), index);
                await lro.PollUntilCompletedAsync();
            }
            catch (RpcException ex) when (ex.StatusCode == StatusCode.AlreadyExists)
            {
                // Assume the index is okay.
            }

            CollectionReference citiesRef = db.Collection("cities");
            Query query = citiesRef
                .WhereGreaterThan("Population", 1000000)
                .WhereLessThan("Density", 10000);
            QuerySnapshot querySnapshot = await query.GetSnapshotAsync();
            foreach (DocumentSnapshot documentSnapshot in querySnapshot)
            {
                var name = documentSnapshot.GetValue<string>("Name");
                var population = documentSnapshot.GetValue<int>("Population");
                var density = documentSnapshot.GetValue<int>("Density");
                Console.WriteLine($"City '{name}' returned by query. Population={population}; Density={density}");
            }
        }

        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 "subcollection-query":
                    SubcollectionQuery(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 "multiple-inequalities":
                    MultipleInequalitiesQuery(project).Wait();
                    break;

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

Program.cs
রুবি 
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

আমরা একটি একক শহরের landmarks উপ-সংগ্রহের জন্য আগে বর্ণিত সহজ এবং যৌগিক ক্যোয়ারী ব্যবহার করতে পারি, তবে আপনি প্রতিটি শহরের landmarks উপ-সংগ্রহ থেকে একবারে ফলাফল পুনরুদ্ধার করতে চাইতে পারেন।

landmarks সংগ্রহ গ্রুপে আইডি landmarks সহ সমস্ত সংগ্রহ রয়েছে এবং আপনি একটি সংগ্রহ গ্রুপ ক্যোয়ারী ব্যবহার করে এটি অনুসন্ধান করতে পারেন। উদাহরণ স্বরূপ, এই সংগ্রহের গ্রুপ কোয়েরিটি সমস্ত শহর জুড়ে সমস্ত museum ল্যান্ডমার্ক পুনরুদ্ধার করে:

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());
});
fs_collection_group_query.js

Web

var museums = db.collectionGroup('landmarks').where('type', '==', 'museum');
museums.get().then((querySnapshot) => {
    querySnapshot.forEach((doc) => {
        console.log(doc.id, ' => ', doc.data());
    });
});
test.firestore.js
সুইফট
দ্রষ্টব্য: এই পণ্যটি watchOS এবং অ্যাপ ক্লিপ লক্ষ্যে উপলব্ধ নয়। 
db.collectionGroup("landmarks").whereField("type", isEqualTo: "museum").getDocuments { (snapshot, error) in
  // ...
}
ViewController.swift
উদ্দেশ্য-C
দ্রষ্টব্য: এই পণ্যটি watchOS এবং অ্যাপ ক্লিপ লক্ষ্যে উপলব্ধ নয়। 
[[[self.db collectionGroupWithID:@"landmarks"] queryWhereField:@"type" isEqualTo:@"museum"]
    getDocumentsWithCompletion:^(FIRQuerySnapshot *snapshot, NSError *error) {
    // ...
}];
ViewController.m

Kotlin 

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

একটি সংগ্রহ গ্রুপ ক্যোয়ারী ব্যবহার করার আগে, আপনাকে অবশ্যই একটি সূচী তৈরি করতে হবে যা আপনার সংগ্রহ গোষ্ঠীর ক্যোয়ারী সমর্থন করে। আপনি একটি ত্রুটি বার্তা, কনসোল বা Firebase CLI এর মাধ্যমে একটি সূচক তৈরি করতে পারেন ।

ওয়েব এবং মোবাইল SDK-এর জন্য, আপনাকে অবশ্যই এমন নিয়মগুলি তৈরি করতে হবে যা আপনার সংগ্রহ গোষ্ঠীর প্রশ্নগুলিকে অনুমতি দেয় ৷

আপনার প্রশ্নের কর্মক্ষমতা ব্যাখ্যা করুন

Cloud Firestore আপনাকে ব্যাকএন্ডে আপনার প্রশ্নের কর্মক্ষমতা পরিমাপ করতে এবং বিনিময়ে ব্যাকএন্ড ক্যোয়ারী সম্পাদনের বিস্তারিত কর্মক্ষমতা পরিসংখ্যান পেতে দেয়।

ক্যোয়ারী ব্যাখ্যা ফলাফল আপনাকে বুঝতে সাহায্য করে কিভাবে আপনার প্রশ্নগুলি কার্যকর করা হয়, আপনাকে অদক্ষতা এবং সম্ভাব্য সার্ভার-সাইড বাধাগুলির অবস্থান দেখায়৷

আরও তথ্যের জন্য, ক্যোয়ারী ব্যাখ্যার জন্য গাইড দেখুন।

প্রশ্ন সীমাবদ্ধতা

নিম্নলিখিত তালিকাটি Cloud Firestore ক্যোয়ারী সীমাবদ্ধতাগুলিকে সংক্ষিপ্ত করে:

  • Cloud Firestore লজিক্যাল OR কোয়েরির জন্য or , in , এবং array-contains-any অপারেটরের মাধ্যমে সমর্থন প্রদান করে। এই ক্যোয়ারীগুলি ক্যোয়ারী এর ডিসজংক্টিভ নরমাল ফর্মের উপর ভিত্তি করে 30 টি ডিসজেকশনের মধ্যে সীমাবদ্ধ।
  • আপনি সর্বাধিক একটি array-contains ব্যবহার করতে পারেন- প্রতি বিচ্ছিন্নতা ( or গোষ্ঠী) ধারা রয়েছে। আপনি একই বিচ্ছিন্নতার মধ্যে array-contains এর সাথে array-contains-any একত্রিত করতে পারবেন না।
  • আপনি not-in এর সাথে in , array-contains-any , or একই ক্যোয়ারীতে একত্রিত করতে পারবেন না৷
  • শুধুমাত্র একটি not-in বা != প্রতি ক্যোয়ারী অনুমোদিত।
  • not-in 10টি পর্যন্ত তুলনা মান সমর্থন করে।
  • একটি ক্যোয়ারীতে ফিল্টার, সাজানোর অর্ডার, এবং প্যারেন্ট ডকুমেন্ট পাথের যোগফল (একটি উপ-সংগ্রহের জন্য 1, একটি রুট সংগ্রহের জন্য 0) 100-এর বেশি হতে পারে না। এটি ক্যোয়ারীটির বিচ্ছিন্ন স্বাভাবিক ফর্মের উপর ভিত্তি করে গণনা করা হয়।
  • একটি ক্ষেত্রে একটি অসমতা ফিল্টার সহ একটি ক্যোয়ারী সেই ক্ষেত্রের দ্বারা ক্রম এবং সেই ক্ষেত্রের অস্তিত্বের জন্য ফিল্টারগুলিকে বোঝায়৷

OR প্রশ্নে সীমাবদ্ধতা

একটি প্রশ্ন যাতে গণনাগতভাবে ব্যয়বহুল হয়ে না যায় তার জন্য, Cloud Firestore আপনি কতগুলি AND এবং OR ধারাগুলি একত্রিত করতে পারেন তা সীমাবদ্ধ করে৷ এই সীমাটি প্রয়োগ করার জন্য, Cloud Firestore এমন প্রশ্নগুলিকে রূপান্তরিত করে যা লজিক্যাল OR ক্রিয়াকলাপ সম্পাদন করে ( or , in , এবং array-contains-any ) ডিসজংক্টিভ নরমাল ফর্মে (এছাড়াও AND গুলির একটি OR হিসাবে পরিচিত)৷ Cloud Firestore ডিসজংক্টিভ নরমাল ফর্মে একটি ক্যোয়ারীকে সর্বাধিক 30টি ডিসজেকশনে সীমাবদ্ধ করে।

বিচ্ছিন্ন স্বাভাবিক ফর্ম

Cloud Firestore দুটি নিয়ম প্রয়োগ করে প্রশ্নগুলিকে বিচ্ছিন্ন স্বাভাবিক ফর্মে রূপান্তর করে:

  • চ্যাপ্টা

    প্রদত্ত শর্ত A , B , এবং C :

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

  • বন্টনমূলক আইন

    প্রদত্ত শর্ত A , B , C , এবং 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)

in এবং array-contains-any প্রশ্নে এই নিয়মগুলি প্রয়োগ করার সময়, মনে রাখবেন যে এই অপারেটরগুলি OR জন্য সংক্ষিপ্ত বিবরণ। উদাহরণস্বরূপ, a in [1,2] a = 1 OR a = 2 এর সংক্ষিপ্তহস্ত।

নিম্নলিখিত উদাহরণগুলি বিভিন্ন প্রশ্নের জন্য বিচ্ছিন্নতার সংখ্যা দেখায়:

প্রশ্ন বিভক্তির সংখ্যা 
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

এই ক্যোয়ারীটির ডিসজংক্টিভ সাধারন ফর্ম উপরের কোয়েরির সমান। 

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

এই ক্যোয়ারীটি একটি ত্রুটি প্রদান করে, কারণ এটি 30টি বিচ্ছিন্নতার সীমা অতিক্রম করে। 

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 এবং অস্তিত্ব

যখন আপনি একটি প্রদত্ত ক্ষেত্র দ্বারা একটি ক্যোয়ারী অর্ডার করেন, তখন ক্যোয়ারীটি শুধুমাত্র সেই নথিগুলি ফেরত দিতে পারে যেখানে অর্ডার-বাই ক্ষেত্র বিদ্যমান থাকে।

উদাহরণস্বরূপ, নিম্নোক্ত ক্যোয়ারী এমন কোনো নথি ফেরত দেবে না যেখানে population ক্ষেত্র সেট করা নেই, এমনকি যদি তারা অন্যথায় ক্যোয়ারী ফিল্টার পূরণ করে।

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

একটি সম্পর্কিত প্রভাব অসমতা প্রযোজ্য. একটি ক্ষেত্রে একটি অসমতা ফিল্টার সহ একটি প্রশ্ন সেই ক্ষেত্রের দ্বারা ক্রম নির্দেশ করে৷ নিম্নোক্ত প্রশ্নটি population ক্ষেত্র ছাড়া নথি ফেরত দেয় না এমনকি যদি সেই নথিতে country = USA থাকে। একটি সমাধান হিসাবে, আপনি প্রতিটি অর্ডারের জন্য পৃথক প্রশ্নগুলি চালাতে পারেন বা আপনি যে সমস্ত ক্ষেত্রে অর্ডার করেন তার জন্য একটি মান নির্ধারণ করতে পারেন৷

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

উপরের ক্যোয়ারীটিতে অসমতার উপর একটি অন্তর্নিহিত আদেশ রয়েছে এবং এটি নিম্নলিখিতগুলির সমতুল্য:

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

এরপর কি