1. Introduction

In this tutorial, we will learn how to build a CRUD (Create, Read, Update, Delete) web application using Firestore, a flexible, scalable database for mobile, web, and server development from Firebase and Google Cloud Platform.

Goals

By the end of this tutorial, you will:

• Understand how to connect to Firestore
• Be able to perform CRUD operations in Firestore
• Have a working web application connected to a Firestore database

Prerequisites

You should have basic knowledge of HTML, CSS, and JavaScript. Familiarity with Firebase is helpful, but not necessary.

2. Step-by-Step Guide

Setting up Firestore

First, create a Firebase account and a new project in Firebase. Navigate to the Firestore Database section and create a new Firestore database.

Connecting to Firestore

In your HTML file, include the Firebase JavaScript library by adding these scripts in your HTML file:

<script src="https://www.gstatic.com/firebasejs/7.24.0/firebase-app.js"></script>
<script src="https://www.gstatic.com/firebasejs/7.24.0/firebase-firestore.js"></script>

Then, initialize Firebase in your JavaScript file:

const firebaseConfig = {
  apiKey: "your-api-key",
  authDomain: "your-auth-domain",
  projectId: "your-project-id"
};

firebase.initializeApp(firebaseConfig);
const db = firebase.firestore();

CRUD Operations

Create

To add a document to Firestore, use the .add() method with your data as an object:

db.collection('users').add({
  firstName: 'John',
  lastName: 'Doe',
  age: 30
});

Read

To get all documents in a collection, use the .get() method:

db.collection('users').get().then((snapshot) => {
  snapshot.docs.forEach(doc => {
    console.log(doc.data());
  });
});

Update

To update a document, use the .update() method:

db.collection('users').doc('document-id').update({
  age: 31
});

Delete

To delete a document, use the .delete() method:

db.collection('users').doc('document-id').delete();

3. Code Examples

Full Example

// Initialize Firebase
firebase.initializeApp(firebaseConfig);
const db = firebase.firestore();

// Add a new document
db.collection('users').add({
  firstName: 'John',
  lastName: 'Doe',
  age: 30
});

// Get all documents
db.collection('users').get().then((snapshot) => {
  snapshot.docs.forEach(doc => {
    console.log(doc.data());
  });
});

// Update a document
db.collection('users').doc('document-id').update({
  age: 31
});

// Delete a document
db.collection('users').doc('document-id').delete();

This example shows how to connect to Firestore and perform CRUD operations. Make sure to replace 'document-id' with the actual ID of the document you want to update or delete.

4. Summary

In this tutorial, we've learned how to connect to Firestore and perform CRUD operations. You have now a grasp on how to create, read, update, and delete documents in Firestore.

5. Practice Exercises

Exercise 1: Create a new collection and add 5 documents to it, each with three different fields.

Exercise 2: Read all documents from the collection you created and log them to the console.

Exercise 3: Update one of the documents you created in Exercise 1.

Exercise 4: Delete one of the documents you created in Exercise 1.

Additional Resources

• Firestore Documentation
• Firestore SDK