How to Get a Document Using its Id in Firestore – With Examples

Firestore allows you to store data in a document format, and documents are grouped into collections.

You can get a document using its id in Firestore using the getDoc(collection(db, “collection_name”, “documentId”)) method.

This tutorial teaches you how to get a document using its id from a collection in Firestore using the getDoc() method, get a document using its id using the query() method and get multiple documents using its id.

Getting a Document Using its Id in Firestore Using getDoc() Method

To get a document using its id,

• Initialize the Firebase app using the Firebase config data
• Get the firestore app as db
• Create a document reference of the document using the document id as doc(db, “collection_name”, “document_id”)
• Pass the document ref to the getDoc() method
• It returns the snapshot if the document exists. You can fetch the details of the document using the snapshot.

Code

The following code demonstrates how to get the document with id coimbatore from the collection cities.

import { initializeApp } from "firebase/app";

import { getFirestore, doc, getDoc  } from "firebase/firestore";

const firebaseConfig = {
  apiKey: “<your_api_key>“,
  authDomain: “<your_auth_domain>“,
  projectId: “<your_project_id>”,
  storageBucket: “<your_Storage_bucket>“,
  messagingSenderId: “<sender_id>“,
  appId: “<your_app_id>“,
  measurementId: “<your_measurement_id>“
};

// Initialize Firebase
const app = initializeApp(firebaseConfig);

const db = getFirestore(app);

async function quickstart() {

  const docRef = doc(db, "cities", "coimbatore");

  const docSnap = await getDoc(docRef);

  if (docSnap.exists()) {

    console.log(docSnap.data());
  }
  else {
    console.log("No such document!");
  }

}

quickstart();

Output

{ shortcode: 'cbe' }

Getting a Document Using its Id in Firestore Using query() Method

To get a document using its id using the query() method,

• Initialize the Firebase app using the Firebase config data
• Get the firestore app as db
• Create a query object with the document id in the where clause. The Where clause column name must be documentId(), and the document IDs to select
• Pass the query object to the getDocs() method
• It returns the snapshot of the selected document. You can access the document from the query snapshot.

Code

The following code demonstrates how to get the document with id coimbatore from the collection cities using the query() method.

import { initializeApp } from "firebase/app";

import { getFirestore, collection, query, where, getDocs,documentId } from "firebase/firestore";

const firebaseConfig = {
  apiKey: “<your_api_key>“,
  authDomain: “<your_auth_domain>“,
  projectId: “<your_project_id>”,
  storageBucket: “<your_Storage_bucket>“,
  messagingSenderId: “<sender_id>“,
  appId: “<your_app_id>“,
  measurementId: “<your_measurement_id>“
};

// Initialize Firebase
const app = initializeApp(firebaseConfig);

const db = getFirestore(app);

async function quickstart() {

  const q = query(
    collection(db, "cities"),
    where(documentId(), "in",
      [
        "chennai"
      ]
    ),
  );
  const querySnapshot = await getDocs(q);

  querySnapshot.forEach((doc) => {
    console.log(doc.id, " => ", doc.data());
  });
}

quickstart();

Output

chennai  =>  { shortcode: 'mas' }

Getting Multiple Documents By ID from FireStore Using getDocs() Method

To get multiple documents by id from Firestore, use the documentId() function in the query method.

• For example, to get the documents with the document id chennai and coimbatore, create a query object like query(collection(db, "cities"), where(documentId(), "in",["chennai","coimbatore”]),)

Code

The following code demonstrates the query method to get documents based on their ids.

import { initializeApp } from "firebase/app";
import { getFirestore, collection, query, where, getDocs,documentId } from "firebase/firestore";

const firebaseConfig = {
  apiKey: “<your_api_key>“,
  authDomain: “<your_auth_domain>“,
  projectId: “<your_project_id>”,
  storageBucket: “<your_Storage_bucket>“,
  messagingSenderId: “<sender_id>“,
  appId: “<your_app_id>“,
  measurementId: “<your_measurement_id>“
};

// Initialize Firebase
const app = initializeApp(firebaseConfig);

const db = getFirestore(app);

async function quickstart() {

  const q = query(
    collection(db, "cities"),
    where(documentId(), "in",
      [
        "chennai",
        "coimbatore"
      ]
    ),
  );
  const querySnapshot = await getDocs(q);

  querySnapshot.forEach((doc) => {
    console.log(doc.id, " => ", doc.data());
  });
}

quickstart();

Output

chennai  =>  { shortcode: 'mas' }
coimbatore  =>  { shortcode: 'cbe' }

Additional Resources

• How to Get All Documents from A Collection in a FireStore
• Solve FireBase Google Cloud Firestore: PERMISSION_DENIED: Missing or insufficient permissions Error