Getting all documents in collection in Firebase - Mini Project: Build & Apply

Getting all documents in a Firebase collection

📖 Scenario: You are building a simple app that shows a list of books stored in a Firebase Firestore database. You want to get all the books from the books collection to display them.

🎯 Goal: Learn how to write code that fetches all documents from the books collection in Firebase Firestore.

📋 What You'll Learn

Create a reference to the books collection

Create a variable to hold the Firestore database instance

Write an async function to get all documents from the books collection

Use the getDocs method to fetch the documents

Store the fetched documents in a variable

💡 Why This Matters

🌍 Real World

Fetching all documents from a collection is a common task in apps that display lists of items like books, products, or users.

💼 Career

Knowing how to query Firestore collections is essential for frontend and backend developers working with Firebase to build real-time and scalable applications.

1

Set up Firestore database instance

Create a constant called db and set it to getFirestore() to get the Firestore database instance.

Firebase

// Your code here

Need a hint?

Use const db = getFirestore() to get the Firestore database instance.

2

Create a reference to the books collection

Create a constant called booksCollection and set it to collection(db, "books") to refer to the books collection in Firestore.

Firebase

import { getFirestore, collection } from "firebase/firestore";

const db = getFirestore();

// Your code here

Need a hint?

Use collection(db, "books") to get the reference to the books collection.

3

Write an async function to get all documents

Write an async function called getAllBooks that uses getDocs(booksCollection) to fetch all documents from the booksCollection. Store the result in a constant called querySnapshot.

Firebase

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

const db = getFirestore();

const booksCollection = collection(db, "books");

// Your code here

Need a hint?

Use async function getAllBooks() and inside it const querySnapshot = await getDocs(booksCollection).

4

Extract and store documents data

Inside the getAllBooks function, create a constant called books that uses querySnapshot.docs.map(doc => doc.data()) to get an array of all book data objects.

Firebase

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

const db = getFirestore();

const booksCollection = collection(db, "books");

async function getAllBooks() {
    const querySnapshot = await getDocs(booksCollection);
    // Your code here
}

Need a hint?

Use const books = querySnapshot.docs.map(doc => doc.data()) to get all book data.