Query a Firestore collection group with an eq filter

Query a Firestore collection group with an eq filter

Explore further

For detailed documentation that includes this code sample, see the following:

• Perform simple and compound queries in Cloud Firestore
• Query and filter data

Code sample

C#

To authenticate to Firestore, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

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")}");
}

Go

To authenticate to Firestore, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

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
}

Java

To authenticate to Firestore, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

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());
}

Node.js

To authenticate to Firestore, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

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

PHP

To authenticate to Firestore, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

$museums = $db->collectionGroup('landmarks')->where('type', '==', 'museum');
foreach ($museums->documents() as $document) {
    printf('%s => %s' . PHP_EOL, $document->id(), $document->data()['name']);
}

Python

To authenticate to Firestore, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

museums = db.collection_group("landmarks").where(
    filter=FieldFilter("type", "==", "museum")
)
docs = museums.stream()
for doc in docs:
    print(f"{doc.id} => {doc.to_dict()}")

Ruby

To authenticate to Firestore, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

museums = firestore.collection_group("landmarks").where("type", "==", "museum")
museums.get do |museum|
  puts "#{museum[:type]} name is #{museum[:name]}."
end

What's next

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