Create a Firestore subcollection reference

Create a Firestore subcollection reference

Explore further

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

• Cloud Firestore Data model
• Data model

Code sample

C#

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

DocumentReference documentRef = db
    .Collection("Rooms").Document("RoomA")
    .Collection("Messages").Document("Message1");

Go

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

import (
	"cloud.google.com/go/firestore"
)

func createSubcollectionReference(client *firestore.Client) {
	messageRef := client.Collection("rooms").Doc("roomA").
		Collection("messages").Doc("message1")

	_ = messageRef
}

Java

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

// Reference to a document in subcollection "messages"
DocumentReference document =
    db.collection("rooms").document("roomA").collection("messages").document("message1");

Node.js

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

const messageRef = db.collection('rooms').doc('roomA')
  .collection('messages').doc('message1');

PHP

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

$document = $db
    ->collection('rooms')
    ->document('roomA')
    ->collection('messages')
    ->document('message1');

Python

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

room_a_ref = db.collection("rooms").document("roomA")
message_ref = room_a_ref.collection("messages").document("message1")

Ruby

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

message_ref = firestore.col("rooms").doc("roomA").col("messages").doc("message1")

What's next

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