Verileri toplama sorgularıyla özetle

Toplama sorgusu, birden çok dizin girişinden gelen verileri tek bir özet değeri döndürecek şekilde işler.

Cloud Firestore, aşağıdaki toplama sorgularını destekler:

  • count()
  • sum()
  • average()

Cloud Firestore, toplama işlemini hesaplar ve yalnızca sonucu uygulamanıza geri iletir. Tam sorgu yürütme ve uygulamanızda toplama işlemini hesaplamaya kıyasla toplama sorguları, hem faturalandırılan belge okumalarında hem de aktarılan baytlarda tasarruf sağlar.

Toplama sorguları, sorgularınızın halihazırda kullandığı mevcut dizin yapılandırmasına dayanır ve taranan dizin girişlerinin sayısıyla orantılı olarak ölçeklendirilir. Toplamadaki öğe sayısı arttıkça gecikme de artar.

count() toplamasını kullanın

count() toplama sorgusu, bir koleksiyon veya sorgudaki belge sayısını belirlemenize olanak tanır.

Veri alma bölümünde ayarladığımız örnek verilere bakın.

Aşağıdaki count() toplaması, cities koleksiyonundaki toplam şehir sayısını döndürür.

Web

const coll = collection(db, "cities");
const snapshot = await getCountFromServer(coll);
console.log('count: ', snapshot.data().count);
Swift
Not: Bu ürün, watchOS ve App Clip hedeflerinde kullanılamaz.
let query = db.collection("cities")
let countQuery = query.count
do {
  let snapshot = try await countQuery.getAggregation(source: .server)
  print(snapshot.count)
} catch {
  print(error)
}
Objective-C
Not: Bu ürün, watchOS ve App Clip hedeflerinde kullanılamaz.
FIRCollectionReference *query = [self.db collectionWithPath:@"cities"];
[query.count aggregationWithSource:FIRAggregateSourceServer
                        completion:^(FIRAggregateQuerySnapshot *snapshot,
                                     NSError *error) {
    if (error != nil) {
        NSLog(@"Error fetching count: %@", error);
    } else {
        NSLog(@"Cities count: %@", snapshot.count);
    }
}];

Java

Query query = db.collection("cities");
AggregateQuery countQuery = query.count();
countQuery.get(AggregateSource.SERVER).addOnCompleteListener(new OnCompleteListener<AggregateQuerySnapshot>() {
    @Override
    public void onComplete(@NonNull Task<AggregateQuerySnapshot> task) {
        if (task.isSuccessful()) {
            // Count fetched successfully
            AggregateQuerySnapshot snapshot = task.getResult();
            Log.d(TAG, "Count: " + snapshot.getCount());
        } else {
            Log.d(TAG, "Count failed: ", task.getException());
        }
    }
});

Kotlin+KTX

val query = db.collection("cities")
val countQuery = query.count()
countQuery.get(AggregateSource.SERVER).addOnCompleteListener { task ->
    if (task.isSuccessful) {
        // Count fetched successfully
        val snapshot = task.result
        Log.d(TAG, "Count: ${snapshot.count}")
    } else {
        Log.d(TAG, "Count failed: ", task.getException())
    }
}

Dart

// Returns number of documents in users collection
db.collection("users").count().get().then(
      (res) => print(res.count),
      onError: (e) => print("Error completing: $e"),
    );
Go
package firestore

import (
	"context"
	"errors"
	"fmt"
	"io"

	"cloud.google.com/go/firestore"
	firestorepb "cloud.google.com/go/firestore/apiv1/firestorepb"
)

func createCountQuery(w io.Writer, projectID string) error {

	// Instantiate the client
	ctx := context.Background()
	client, err := firestore.NewClient(ctx, projectID)
	if err != nil {
		return err
	}
	defer client.Close()

	collection := client.Collection("users")
	query := collection.Where("born", ">", 1850)

	// `alias` argument--"all"--provides a key for accessing the aggregate query
	// results. The alias value must be unique across all aggregation aliases in
	// an aggregation query and must conform to allowed Document field names.
	//
	// See https://cloud.google.com/firestore/docs/reference/rpc/google.firestore.v1#document for details.
	aggregationQuery := query.NewAggregationQuery().WithCount("all")
	results, err := aggregationQuery.Get(ctx)
	if err != nil {
		return err
	}

	count, ok := results["all"]
	if !ok {
		return errors.New("firestore: couldn't get alias for COUNT from results")
	}

	countValue := count.(*firestorepb.Value)
	fmt.Fprintf(w, "Number of results from query: %d\n", countValue.GetIntegerValue())
	return nil
}
Java
CollectionReference collection = db.collection("cities");
AggregateQuerySnapshot snapshot = collection.count().get().get();
System.out.println("Count: " + snapshot.getCount());
      
Node.js
const collectionRef = db.collection('cities');
const snapshot = await collectionRef.count().get();
console.log(snapshot.data().count);
      
Python
from google.cloud import firestore
from google.cloud.firestore_v1 import aggregation
from google.cloud.firestore_v1.base_query import FieldFilter


def create_count_query(project_id: str) -> None:
    """Builds an aggregate query that returns the number of results in the query.

    Arguments:
      project_id: your Google Cloud Project ID
    """
    client = firestore.Client(project=project_id)

    collection_ref = client.collection("users")
    query = collection_ref.where(filter=FieldFilter("born", ">", 1800))
    aggregate_query = aggregation.AggregationQuery(query)

    # `alias` to provides a key for accessing the aggregate query results
    aggregate_query.count(alias="all")

    results = aggregate_query.get()
    for result in results:
        print(f"Alias of results from query: {result[0].alias}")
        print(f"Number of results from query: {result[0].value}")

count() toplama işlemi, sorgudaki tüm filtreleri ve tüm limit ifadelerini dikkate alır.

Web

const coll = collection(db, "cities");
const q = query(coll, where("state", "==", "CA"));
const snapshot = await getCountFromServer(q);
console.log('count: ', snapshot.data().count);
Swift
Not: Bu ürün, watchOS ve App Clip hedeflerinde kullanılamaz.
let query = db.collection("cities").whereField("state", isEqualTo: "CA")
let countQuery = query.count
do {
  let snapshot = try await countQuery.getAggregation(source: .server)
  print(snapshot.count)
} catch {
  print(error)
}
Objective-C
Not: Bu ürün, watchOS ve App Clip hedeflerinde kullanılamaz.
FIRQuery *query =
    [[self.db collectionWithPath:@"cities"]
                 queryWhereField:@"state"
                       isEqualTo:@"CA"];
[query.count aggregationWithSource:FIRAggregateSourceServer
                        completion:^(FIRAggregateQuerySnapshot *snapshot,
                                      NSError *error) {
    if (error != nil) {
        NSLog(@"Error fetching count: %@", error);
    } else {
        NSLog(@"Cities count: %@", snapshot.count);
    }
}];

Java

Query query = db.collection("cities").whereEqualTo("state", "CA");
AggregateQuery countQuery = query.count();
countQuery.get(AggregateSource.SERVER).addOnCompleteListener(new OnCompleteListener<AggregateQuerySnapshot>() {
    @Override
    public void onComplete(@NonNull Task<AggregateQuerySnapshot> task) {
        if (task.isSuccessful()) {
            // Count fetched successfully
            AggregateQuerySnapshot snapshot = task.getResult();
            Log.d(TAG, "Count: " + snapshot.getCount());
        } else {
            Log.d(TAG, "Count failed: ", task.getException());
        }
    }
});

Kotlin+KTX

val query = db.collection("cities").whereEqualTo("state", "CA")
val countQuery = query.count()
countQuery.get(AggregateSource.SERVER).addOnCompleteListener { task ->
    if (task.isSuccessful) {
        // Count fetched successfully
        val snapshot = task.result
        Log.d(TAG, "Count: ${snapshot.count}")
    } else {
        Log.d(TAG, "Count failed: ", task.getException())
    }
}

Dart

// This also works with collectionGroup queries.
db.collection("users").where("age", isGreaterThan: 10).count().get().then(
      (res) => print(res.count),
      onError: (e) => print("Error completing: $e"),
    );
Go
package firestore

import (
	"context"
	"errors"
	"fmt"
	"io"

	"cloud.google.com/go/firestore"
	firestorepb "cloud.google.com/go/firestore/apiv1/firestorepb"
)

func createCountQuery(w io.Writer, projectID string) error {

	// Instantiate the client
	ctx := context.Background()
	client, err := firestore.NewClient(ctx, projectID)
	if err != nil {
		return err
	}
	defer client.Close()

	collection := client.Collection("users")
	query := collection.Where("born", ">", 1850)

	// `alias` argument--"all"--provides a key for accessing the aggregate query
	// results. The alias value must be unique across all aggregation aliases in
	// an aggregation query and must conform to allowed Document field names.
	//
	// See https://cloud.google.com/firestore/docs/reference/rpc/google.firestore.v1#document for details.
	aggregationQuery := query.NewAggregationQuery().WithCount("all")
	results, err := aggregationQuery.Get(ctx)
	if err != nil {
		return err
	}

	count, ok := results["all"]
	if !ok {
		return errors.New("firestore: couldn't get alias for COUNT from results")
	}

	countValue := count.(*firestorepb.Value)
	fmt.Fprintf(w, "Number of results from query: %d\n", countValue.GetIntegerValue())
	return nil
}
Java
CollectionReference collection = db.collection("cities");
Query query = collection.whereEqualTo("state", "CA");
AggregateQuerySnapshot snapshot = query.count().get().get();
System.out.println("Count: " + snapshot.getCount());
      
Node.js
const collectionRef = db.collection('cities');
const query = collectionRef.where('state', '==', 'CA');
const snapshot = await query.count().get();
console.log(snapshot.data().count);
      
Python
from google.cloud import firestore
from google.cloud.firestore_v1 import aggregation
from google.cloud.firestore_v1.base_query import FieldFilter


def create_count_query(project_id: str) -> None:
    """Builds an aggregate query that returns the number of results in the query.

    Arguments:
      project_id: your Google Cloud Project ID
    """
    client = firestore.Client(project=project_id)

    collection_ref = client.collection("users")
    query = collection_ref.where(filter=FieldFilter("born", ">", 1800))
    aggregate_query = aggregation.AggregationQuery(query)

    # `alias` to provides a key for accessing the aggregate query results
    aggregate_query.count(alias="all")

    results = aggregate_query.get()
    for result in results:
        print(f"Alias of results from query: {result[0].alias}")
        print(f"Number of results from query: {result[0].value}")

sum() toplamasını kullanın

Belirli bir sorguyla eşleşen sayısal değerlerin toplamını döndürmek için sum() toplamasını kullanın. Örneğin:

Web

const coll = collection(firestore, 'cities');
const snapshot = await getAggregateFromServer(coll, {
  totalPopulation: sum('population')
});

console.log('totalPopulation: ', snapshot.data().totalPopulation);
    
Swift
Not: Bu ürün, watchOS ve App Clip hedeflerinde kullanılamaz.
let query = db.collection("cities")
let aggregateQuery = query.aggregate([AggregateField.sum("population")])
do {
  let snapshot = try await aggregateQuery.getAggregation(source: .server)
  print(snapshot.get(AggregateField.sum("population")))
} catch {
  print(error)
}
Objective-C
Not: Bu ürün, watchOS ve App Clip hedeflerinde kullanılamaz.
FIRQuery *query = [self.db collectionWithPath:@"cities"];
FIRAggregateQuery *aggregateQuery = [query aggregate:@[
    [FIRAggregateField aggregateFieldForSumOfField:@"population"]]];
[aggregateQuery aggregationWithSource:FIRAggregateSourceServer
                           completion:^(FIRAggregateQuerySnapshot *snapshot,
                                        NSError *error) {
    if (error != nil) {
        NSLog(@"Error fetching aggregate: %@", error);
    } else {
        NSLog(@"Sum: %@", [snapshot valueForAggregateField:[FIRAggregateField aggregateFieldForSumOfField:@"population"]]);
    }
}];

Java

Query query = db.collection("cities");
AggregateQuery aggregateQuery = query.aggregate(AggregateField.sum("population"));
aggregateQuery.get(AggregateSource.SERVER).addOnCompleteListener(new OnCompleteListener<AggregateQuerySnapshot>() {
    @Override
    public void onComplete(@NonNull Task<AggregateQuerySnapshot> task) {
        if (task.isSuccessful()) {
            // Aggregate fetched successfully
            AggregateQuerySnapshot snapshot = task.getResult();
            Log.d(TAG, "Sum: " + snapshot.get(AggregateField.sum("population")));
        } else {
            Log.d(TAG, "Aggregation failed: ", task.getException());
        }
    }
});

Kotlin+KTX

val query = db.collection("cities")
val aggregateQuery = query.aggregate(AggregateField.sum("population"))
aggregateQuery.get(AggregateSource.SERVER).addOnCompleteListener { task ->
    if (task.isSuccessful) {
        // Aggregate fetched successfully
        val snapshot = task.result
        Log.d(TAG, "Sum: ${snapshot.get(AggregateField.sum("population"))}")
    } else {
        Log.d(TAG, "Aggregate failed: ", task.getException())
    }
}
Java
collection = db.collection("cities");
snapshot = collection.aggregate(sum("population")).get().get();
System.out.println("Sum: " + snapshot.get(sum("population")));
      
Node.js
const coll = firestore.collection('cities');
const sumAggregateQuery = coll.aggregate({
         totalPopulation: AggregateField.sum('population'),
       });
  
const snapshot = await sumAggregateQuery.get();
console.log('totalPopulation: ', snapshot.data().totalPopulation);
      
Python
collection_ref = client.collection("users")
aggregate_query = aggregation.AggregationQuery(collection_ref)

aggregate_query.sum("coins", alias="sum")

results = aggregate_query.get()
for result in results:
    print(f"Alias of results from query: {result[0].alias}")
    print(f"Sum of results from query: {result[0].value}")
      
Go
func createSumQuery(w io.Writer, projectID string) error {
  ctx := context.Background()
  client, err := firestore.NewClient(ctx, projectID)
  if err != nil {
    return err
  }
  defer client.Close()

  collection := client.Collection("users")
  query := collection.Where("born", ">", 1850)

  aggregationQuery := query.NewAggregationQuery().WithSum("coins", "sum_coins")
  results, err := aggregationQuery.Get(ctx)
  if err != nil {
    return err
  }

  sum, ok := results["sum_coins"]
  if !ok {
    return errors.New("firestore: couldn't get alias for SUM from results")
  }

  sumValue := sum.(*firestorepb.Value)
  fmt.Fprintf(w, "Sum of results from query: %d\n", sumValue.GetIntegerValue())
  return nil
}
      

sum() toplama, sorgudaki tüm filtreleri ve tüm sınır ifadelerini dikkate alır. Örneğin:

Web

const coll = collection(firestore, 'cities');
const q = query(coll, where('capital', '==', true));
const snapshot = await getAggregateFromServer(q, {
  totalPopulation: sum('population')
});

console.log('totalPopulation: ', snapshot.data().totalPopulation);
      
Swift
Not: Bu ürün, watchOS ve App Clip hedeflerinde kullanılamaz.
let query = db.collection("cities").whereField("capital", isEqualTo: true)
let aggregateQuery = query.aggregate([AggregateField.sum("population")])
do {
  let snapshot = try await aggregateQuery.getAggregation(source: .server)
  print(snapshot.get(AggregateField.sum("population")))
} catch {
  print(error)
}
Objective-C
Not: Bu ürün, watchOS ve App Clip hedeflerinde kullanılamaz.
FIRQuery *query = [[self.db collectionWithPath:@"cities"]
                   queryWhereFilter:[FIRFilter filterWhereField:@"capital" isEqualTo:@YES]];
FIRAggregateQuery *aggregateQuery = [query aggregate:@[
    [FIRAggregateField aggregateFieldForSumOfField:@"population"]]];
[aggregateQuery aggregationWithSource:FIRAggregateSourceServer
                           completion:^(FIRAggregateQuerySnapshot *snapshot,
                                        NSError *error) {
    if (error != nil) {
        NSLog(@"Error fetching aggregate: %@", error);
    } else {
        NSLog(@"Sum: %@", [snapshot valueForAggregateField:[FIRAggregateField aggregateFieldForSumOfField:@"population"]]);
    }
}];

Java

Query query = db.collection("cities").whereEqualTo("capital", true);
AggregateQuery aggregateQuery = query.aggregate(AggregateField.sum("population"));
aggregateQuery.get(AggregateSource.SERVER).addOnCompleteListener(new OnCompleteListener<AggregateQuerySnapshot>() {
    @Override
    public void onComplete(@NonNull Task<AggregateQuerySnapshot> task) {
        if (task.isSuccessful()) {
            // Aggregate fetched successfully
            AggregateQuerySnapshot snapshot = task.getResult();
            Log.d(TAG, "Sum: " + snapshot.get(AggregateField.sum("population")));
        } else {
            Log.d(TAG, "Aggregation failed: ", task.getException());
        }
    }
});

Kotlin+KTX

val query = db.collection("cities").whereEqualTo("capital", true)
val aggregateQuery = query.aggregate(AggregateField.sum("population"))
aggregateQuery.get(AggregateSource.SERVER).addOnCompleteListener { task ->
    if (task.isSuccessful) {
        // Aggregate fetched successfully
        val snapshot = task.result
        Log.d(TAG, "Sum: ${snapshot.get(AggregateField.sum("population"))}")
    } else {
        Log.d(TAG, "Aggregate failed: ", task.getException())
    }
}
Java
collection = db.collection("cities");
query = collection.whereEqualTo("state", "CA");
snapshot = query.aggregate(sum("population")).get().get();
System.out.println("Sum: " + snapshot.get(sum("population")));
      
Node.js
const coll = firestore.collection('cities');
const q = coll.where("capital", "==", true);
const sumAggregateQuery = q.aggregate({
        totalPopulation: AggregateField.sum('population'),
      });

const snapshot = await sumAggregateQuery.get();
console.log('totalPopulation: ', snapshot.data().totalPopulation);
      
Python
collection_ref = client.collection("users")
query = collection_ref.where(filter=FieldFilter("people", "==", "Matthew"))
aggregate_query = aggregation.AggregationQuery(query)

aggregate_query.sum("coins", alias="sum")

results = aggregate_query.get()
for result in results:
    print(f"Alias of results from query: {result[0].alias}")
    print(f"Sum of results from query: {result[0].value}")
      
Go
func createSumQuery(w io.Writer, projectID string) error {
  ctx := context.Background()
  client, err := firestore.NewClient(ctx, projectID)
  if err != nil {
    return err
  }
  defer client.Close()

  collection := client.Collection("users")
  query := collection.Where("born", ">", 1850).Limit(5)

  aggregationQuery := query.NewAggregationQuery().WithSum("coins", "sum_coins")
  results, err := aggregationQuery.Get(ctx)
  if err != nil {
    return err
  }

  sum, ok := results["sum_coins"]
  if !ok {
    return errors.New("firestore: couldn't get alias for SUM from results")
  }

  sumValue := sum.(*firestorepb.Value)
  fmt.Fprintf(w, "Sum of results from query: %d\n", sumValue.GetIntegerValue())
  return nil
}
      

average() toplamasını kullanın

Belirli bir sorguyla eşleşen sayısal değerlerin ortalamasını döndürmek için average() toplamasını kullanın. Örneğin:

Web

const coll = collection(firestore, 'cities');
const snapshot = await getAggregateFromServer(coll, {
  averagePopulation: average('population')
});

console.log('averagePopulation: ', snapshot.data().averagePopulation);
    
Swift
Not: Bu ürün, watchOS ve App Clip hedeflerinde kullanılamaz.
let query = db.collection("cities")
let aggregateQuery = query.aggregate([AggregateField.average("population")])
do {
  let snapshot = try await aggregateQuery.getAggregation(source: .server)
  print(snapshot.get(AggregateField.average("population")))
} catch {
  print(error)
}
Objective-C
Not: Bu ürün, watchOS ve App Clip hedeflerinde kullanılamaz.
FIRQuery *query = [self.db collectionWithPath:@"cities"];
FIRAggregateQuery *aggregateQuery = [query aggregate:@[
    [FIRAggregateField aggregateFieldForAverageOfField:@"population"]]];
[aggregateQuery aggregationWithSource:FIRAggregateSourceServer
                           completion:^(FIRAggregateQuerySnapshot *snapshot,
                                        NSError *error) {
    if (error != nil) {
        NSLog(@"Error fetching aggregate: %@", error);
    } else {
        NSLog(@"Avg: %@", [snapshot valueForAggregateField:[FIRAggregateField aggregateFieldForAverageOfField:@"population"]]);
    }
}];

Java

Query query = db.collection("cities");
AggregateQuery aggregateQuery = query.aggregate(AggregateField.average("population"));
aggregateQuery.get(AggregateSource.SERVER).addOnCompleteListener(new OnCompleteListener<AggregateQuerySnapshot>() {
    @Override
    public void onComplete(@NonNull Task<AggregateQuerySnapshot> task) {
        if (task.isSuccessful()) {
            // Aggregate fetched successfully
            AggregateQuerySnapshot snapshot = task.getResult();
            Log.d(TAG, "Average: " + snapshot.get(AggregateField.average("population")));
        } else {
            Log.d(TAG, "Aggregation failed: ", task.getException());
        }
    }
});

Kotlin+KTX

val query = db.collection("cities")
val aggregateQuery = query.aggregate(AggregateField.average("population"))
aggregateQuery.get(AggregateSource.SERVER).addOnCompleteListener { task ->
    if (task.isSuccessful) {
        // Aggregate fetched successfully
        val snapshot = task.result
        Log.d(TAG, "Average: ${snapshot.get(AggregateField.average("population"))}")
    } else {
        Log.d(TAG, "Aggregate failed: ", task.getException())
    }
}
Java
collection = db.collection("cities");
snapshot = collection.aggregate(average("population")).get().get();
System.out.println("Average: " + snapshot.get(average("population")));
      
Node.js
const coll = firestore.collection('cities');
const averageAggregateQuery = coll.aggregate({
        averagePopulation: AggregateField.average('population'),
      });

const snapshot = await averageAggregateQuery.get();
console.log('averagePopulation: ', snapshot.data().averagePopulation);
      
Python
collection_ref = client.collection("users")
aggregate_query = aggregation.AggregationQuery(collection_ref)

aggregate_query.avg("coins", alias="avg")

results = aggregate_query.get()
for result in results:
    print(f"Alias of results from query: {result[0].alias}")
    print(f"Average of results from query: {result[0].value}")
      
Go
func createAvgQuery(w io.Writer, projectID string) error {
  ctx := context.Background()
  client, err := firestore.NewClient(ctx, projectID)
  if err != nil {
          return err
  }
  defer client.Close()

  collection := client.Collection("users")
  query := collection.Where("born", ">", 1850)

  aggregationQuery := query.NewAggregationQuery().WithAvg("coins", "avg_coins")
  results, err := aggregationQuery.Get(ctx)
  if err != nil {
    return err
  }

  avg, ok := results["avg_coins"]
  if !ok {
    return errors.New("firestore: couldn't get alias for AVG from results")
  }

  avgValue := avg.(*firestorepb.Value)
  fmt.Fprintf(w, "Avg of results from query: %d\n", avgValue.GetDoubleValue())
  return nil
}
      

average() toplama, sorgudaki tüm filtreleri ve sınır tümcelerini dikkate alır. Örneğin:

Web

const coll = collection(firestore, 'cities');
const q = query(coll, where('capital', '==', true));
const snapshot = await getAggregateFromServer(q, {
  averagePopulation: average('population')
});

console.log('averagePopulation: ', snapshot.data().averagePopulation);
      
Swift
Not: Bu ürün, watchOS ve App Clip hedeflerinde kullanılamaz.
let query = db.collection("cities").whereField("capital", isEqualTo: true)
let aggregateQuery = query.aggregate([AggregateField.average("population")])
do {
  let snapshot = try await aggregateQuery.getAggregation(source: .server)
  print(snapshot.get(AggregateField.average("population")))
} catch {
  print(error)
}
Objective-C
Not: Bu ürün, watchOS ve App Clip hedeflerinde kullanılamaz.
FIRQuery *query = [[self.db collectionWithPath:@"cities"]
                   queryWhereFilter:[FIRFilter filterWhereField:@"capital" isEqualTo:@YES]];
FIRAggregateQuery *aggregateQuery = [query aggregate:@[
    [FIRAggregateField aggregateFieldForAverageOfField:@"population"]]];
[aggregateQuery aggregationWithSource:FIRAggregateSourceServer
                           completion:^(FIRAggregateQuerySnapshot *snapshot,
                                        NSError *error) {
    if (error != nil) {
        NSLog(@"Error fetching aggregate: %@", error);
    } else {
        NSLog(@"Avg: %@", [snapshot valueForAggregateField:[FIRAggregateField aggregateFieldForAverageOfField:@"population"]]);
    }
}];

Java

Query query = db.collection("cities").whereEqualTo("capital", true);
AggregateQuery aggregateQuery = query.aggregate(AggregateField.average("population"));
aggregateQuery.get(AggregateSource.SERVER).addOnCompleteListener(new OnCompleteListener<AggregateQuerySnapshot>() {
    @Override
    public void onComplete(@NonNull Task<AggregateQuerySnapshot> task) {
        if (task.isSuccessful()) {
            // Aggregate fetched successfully
            AggregateQuerySnapshot snapshot = task.getResult();
            Log.d(TAG, "Average: " + snapshot.get(AggregateField.average("population")));
        } else {
            Log.d(TAG, "Aggregation failed: ", task.getException());
        }
    }
});

Kotlin+KTX

val query = db.collection("cities").whereEqualTo("capital", true)
val aggregateQuery = query.aggregate(AggregateField.average("population"))
aggregateQuery.get(AggregateSource.SERVER).addOnCompleteListener { task ->
    if (task.isSuccessful) {
        // Aggregate fetched successfully
        val snapshot = task.result
        Log.d(TAG, "Average: ${snapshot.get(AggregateField.average("population"))}")
    } else {
        Log.d(TAG, "Aggregate failed: ", task.getException())
    }
}
Java
collection = db.collection("cities");
query = collection.whereEqualTo("state", "CA");
snapshot = query.aggregate(average("population")).get().get();
System.out.println("Average: " + snapshot.get(average("population")));
  
Node.js
const coll = firestore.collection('cities');
const q = coll.where("capital", "==", true);
const averageAggregateQuery = q.aggregate({
        averagePopulation: AggregateField.average('population'),
      });

const snapshot = await averageAggregateQuery.get();
console.log('averagePopulation: ', snapshot.data().averagePopulation);
      
Python
collection_ref = client.collection("users")
query = collection_ref.where(filter=FieldFilter("people", "==", "Matthew"))
aggregate_query = aggregation.AggregationQuery(query)

aggregate_query.avg("coins", alias="avg")

results = aggregate_query.get()
for result in results:
    print(f"Alias of results from query: {result[0].alias}")
    print(f"Average of results from query: {result[0].value}")
      
Go
func createAvgQuery(w io.Writer, projectID string) error {
  ctx := context.Background()
  client, err := firestore.NewClient(ctx, projectID)
  if err != nil {
        return err
  }
  defer client.Close()

  collection := client.Collection("users")
  query := collection.Where("born", ">", 1850).Limit(5)

  aggregationQuery := query.NewAggregationQuery().WithAvg("coins", "avg_coins")
  results, err := aggregationQuery.Get(ctx)
  if err != nil {
    return err
  }

  avg, ok := results["avg_coins"]
  if !ok {
    return errors.New("firestore: couldn't get alias for AVG from results")
  }

  avgValue := avg.(*firestorepb.Value)
  fmt.Fprintf(w, "Avg of results from query: %d\n", avgValue.GetDoubleValue())
  return nil
}
      

Bir sorguda birden çok toplama hesaplama

Birden fazla toplama işlemini tek bir toplama ardışık düzeninde birleştirebilirsiniz. Bu, gereken dizin okuması sayısını azaltabilir. Sorgu birden fazla alanda toplamalar içeriyorsa sorgu bileşik dizin gerektirebilir. Bu durumda Cloud Firestore bir dizin önerir.

Aşağıdaki örnek, tek bir toplama sorgusunda birden fazla toplama gerçekleştirir:

Web

const coll = collection(firestore, 'cities');
const snapshot = await getAggregateFromServer(coll, {
  countOfDocs: count(),
  totalPopulation: sum('population'),
  averagePopulation: average('population')
});

console.log('countOfDocs: ', snapshot.data().countOfDocs);
console.log('totalPopulation: ', snapshot.data().totalPopulation);
console.log('averagePopulation: ', snapshot.data().averagePopulation);
      
Swift
Not: Bu ürün, watchOS ve App Clip hedeflerinde kullanılamaz.
let query = db.collection("cities")
let aggregateQuery = query.aggregate([
  AggregateField.count(),
  AggregateField.sum("population"),
  AggregateField.average("population")])
do {
  let snapshot = try await aggregateQuery.getAggregation(source: .server)
  print("Count: \(snapshot.get(AggregateField.count()))")
  print("Sum: \(snapshot.get(AggregateField.sum("population")))")
  print("Average: \(snapshot.get(AggregateField.average("population")))")
} catch {
  print(error)
}
Objective-C
Not: Bu ürün, watchOS ve App Clip hedeflerinde kullanılamaz.
FIRQuery *query = [self.db collectionWithPath:@"cities"];
FIRAggregateQuery *aggregateQuery = [query aggregate:@[
    [FIRAggregateField aggregateFieldForCount],
    [FIRAggregateField aggregateFieldForSumOfField:@"population"],
    [FIRAggregateField aggregateFieldForAverageOfField:@"population"]]];
[aggregateQuery aggregationWithSource:FIRAggregateSourceServer
                           completion:^(FIRAggregateQuerySnapshot *snapshot,
                                        NSError *error) {
    if (error != nil) {
        NSLog(@"Error fetching aggregate: %@", error);
    } else {
        NSLog(@"Count: %@", [snapshot valueForAggregateField:[FIRAggregateField aggregateFieldForCount]]);
        NSLog(@"Sum: %@", [snapshot valueForAggregateField:[FIRAggregateField aggregateFieldForSumOfField:@"population"]]);
        NSLog(@"Avg: %@", [snapshot valueForAggregateField:[FIRAggregateField aggregateFieldForAverageOfField:@"population"]]);
    }
}];

Java

Query query = db.collection("cities");
AggregateQuery aggregateQuery = query.aggregate(
        AggregateField.count(),
        AggregateField.sum("population"),
        AggregateField.average("population"));
aggregateQuery.get(AggregateSource.SERVER).addOnCompleteListener(new OnCompleteListener<AggregateQuerySnapshot>() {
    @Override
    public void onComplete(@NonNull Task<AggregateQuerySnapshot> task) {
        if (task.isSuccessful()) {
            // Aggregate fetched successfully
            AggregateQuerySnapshot snapshot = task.getResult();
            Log.d(TAG, "Count: " + snapshot.get(AggregateField.count()));
            Log.d(TAG, "Sum: " + snapshot.get(AggregateField.sum("population")));
            Log.d(TAG, "Average: " + snapshot.get(AggregateField.average("population")));
        } else {
            Log.d(TAG, "Aggregation failed: ", task.getException());
        }
    }
});

Kotlin+KTX

val query = db.collection("cities")
val aggregateQuery = query.aggregate(
    AggregateField.count(),
    AggregateField.sum("population"),
    AggregateField.average("population")
)
aggregateQuery.get(AggregateSource.SERVER).addOnCompleteListener { task ->
    if (task.isSuccessful) {
        // Aggregate fetched successfully
        val snapshot = task.result
        Log.d(TAG, "Count: ${snapshot.get(AggregateField.count())}")
        Log.d(TAG, "Sum: ${snapshot.get(AggregateField.sum("population"))}")
        Log.d(TAG, "Average: ${snapshot.get(AggregateField.average("population"))}")
    } else {
        Log.d(TAG, "Aggregate failed: ", task.getException())
    }
}
Java
collection = db.collection("cities");
query = collection.whereEqualTo("state", "CA");
AggregateQuery aggregateQuery = query.aggregate(count(), sum("population"), average("population"));
snapshot = aggregateQuery.get().get();
System.out.println("Count: " + snapshot.getCount());
System.out.println("Sum: " + snapshot.get(sum("population")));
System.out.println("Average: " + snapshot.get(average("population")));
    
Node.js
const coll = firestore.collection('cities');
const aggregateQuery = coll.aggregate({
    countOfDocs: AggregateField.count(),
    totalPopulation: AggregateField.sum('population'),
    averagePopulation: AggregateField.average('population')
  });

const snapshot = await aggregateQuery.get();
console.log('countOfDocs: ', snapshot.data().countOfDocs);
console.log('totalPopulation: ', snapshot.data().totalPopulation);
console.log('averagePopulation: ', snapshot.data().averagePopulation);
      
Python
collection_ref = client.collection("users")
query = collection_ref.where(filter=FieldFilter("people", "==", "Matthew"))
aggregate_query = aggregation.AggregationQuery(query)

aggregate_query.sum("coins", alias="sum").avg("coins", alias="avg")

results = aggregate_query.get()
for result in results:
    print(f"Alias of results from query: {result[0].alias}")
    print(f"Aggregation of results from query: {result[0].value}")
      
Go
func createMultiAggregationQuery(w io.Writer, projectID string) error {
  ctx := context.Background()
  client, err := firestore.NewClient(ctx, projectID)
  if err != nil {
    return err
  }
  defer client.Close()

  collection := client.Collection("users")
  query := collection.Where("born", ">", 1850)

  aggregationQuery := query.NewAggregationQuery().WithCount("count").WithSum("coins", "sum_coins").WithAvg("coins", "avg_coins")
  results, err := aggregationQuery.Get(ctx)
  if err != nil {
    return err
  }
}
      

Birden fazla toplama içeren sorgular, yalnızca her toplamadaki tüm alanları içeren belgeleri içerir. Bu durum, her toplamanın ayrı ayrı gerçekleştirilmesinden farklı sonuçlar elde edilmesine yol açabilir.

Toplama sorguları için güvenlik kuralları

Cloud Firestore Güvenlik Kuralları, toplama sorgularında ve belge döndüren sorgularda aynı şekilde çalışır. Başka bir deyişle, kurallarınız yalnızca istemcilerin belirli koleksiyon veya koleksiyon grubu sorgularını yürütmesine izin veriyorsa istemciler toplama işlemini bu sorgularda da gerçekleştirebilir. Cloud Firestore Güvenlik Kurallarının sorgularla nasıl etkileşimde bulunduğu hakkında daha fazla bilgi edinin.

Davranış ve sınırlamalar

Toplama sorgularıyla çalışırken aşağıdaki davranış ve sınırlamaları dikkate alın:

  • Toplama sorgularını gerçek zamanlı işleyiciler ve çevrimdışı sorgularla kullanamazsınız. Toplama sorguları yalnızca doğrudan sunucu yanıtı aracılığıyla desteklenir. Sorgular, yerel önbelleği ve arabelleğe alınan güncellemeler atlanarak yalnızca Cloud Firestore arka ucu tarafından sunulur. Bu davranış, Cloud Firestore işlemleri içinde gerçekleştirilen işlemlerle aynıdır.

  • Toplama işlemi 60 saniye içinde çözümlenemezse DEADLINE_EXCEEDED hatası döndürür. Performans, dizin yapılandırmanıza ve veri kümesinin boyutuna bağlıdır.

    İşlem 60 saniyelik süre içinde tamamlanamazsa büyük veri kümeleri için sayaç kullanmak uygun bir çözüm olabilir.

  • Toplama sorguları dizin girişlerinden okunur ve yalnızca dizine eklenmiş alanları içerir.

  • Toplama sorgusuna OrderBy ifadesi eklemek, toplama işlemini sıralama alanının mevcut olduğu belgelerle sınırlar.

  • sum() ve average() toplamaları için sayısal olmayan değerler yok sayılır. sum() ve average() toplamaları yalnızca tam sayı değerlerini ve kayan nokta değerlerini dikkate alır.

  • Birden fazla toplama işlemini tek bir sorguda birleştirirken sum() ve average()'nin sayısal olmayan değerleri yok saydığını, count()'nin ise sayısal olmayan değerler içerdiğini unutmayın.

  • Farklı alanlarda bulunan toplamaları birleştirirseniz hesaplama yalnızca bu alanların tümünü içeren dokümanları dahil eder.

Fiyatlandırma

Toplama sorgularının fiyatlandırması, sorgu tarafından eşleşen dizin girişlerinin sayısına bağlıdır. Çok sayıda eşleşen giriş için az sayıda okuma ücreti alınır.

Daha ayrıntılı fiyatlandırma bilgilerine göz atın.