Firebase Realtime Database: Usage and Examples

Firebase Realtime Database is a cloud-hosted NoSQL database that supports real-time data syncing across all clients. Below are the basic operations and examples on how to interact with Firebase Realtime Database.

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1. Setting Up Firebase in Your Project

Before using Firebase Realtime Database, ensure you have set up Firebase in your project.

Web Setup:

1. Create a Firebase project in the Firebase Console.

2. Add Firebase SDK to your web project:

   • Go to the Firebase console, navigate to your project, and click on "Web" under the "Get Started" section.
   • Copy the Firebase configuration object, which will look like this:

     const firebaseConfig = {
       apiKey: "YOUR_API_KEY",
       authDomain: "your-project-id.firebaseapp.com",
       databaseURL: "https://your-project-id.firebaseio.com",
       projectId: "your-project-id",
       storageBucket: "your-project-id.appspot.com",
       messagingSenderId: "your-messaging-sender-id",
       appId: "your-app-id",
     };
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3. Add the Firebase SDK to your HTML file:

   <script src="https://www.gstatic.com/firebasejs/9.6.1/firebase-app.js"></script>
   <script src="https://www.gstatic.com/firebasejs/9.6.1/firebase-database.js"></script>
   <script>
     // Initialize Firebase
     const app = firebase.initializeApp(firebaseConfig);
     const database = firebase.database(app);
   </script>
   📝

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2. Writing Data to Firebase Realtime Database

You can write data to Firebase using the set() and push() methods.

Example 1: Using set() to Write Data

The set() method will overwrite the data at the specific reference.

// Reference to the database location
const dbRef = firebase.database().ref("users/");

// Set data at the 'users' reference
dbRef.set({
  user1: {
    name: "John Doe",
    email: "john.doe@example.com",
    age: 30,
  },
  user2: {
    name: "Jane Doe",
    email: "jane.doe@example.com",
    age: 28,
  },
});
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