Realtime Database
Realtime Database
Firebase Realtime Database is a cloud-hosted NoSQL database that stores data as a single large JSON tree, synchronizing changes to connected clients in real time with very low latency.
Installing Realtime Database
bash
npm install @react-native-firebase/database
Writing Data
javascript
import database from '@react-native-firebase/database';
await database().ref('/users/1').set({
name: 'John Doe',
online: true,
});
Reading Data Once
javascript
const snapshot = await database().ref('/users/1').once('value');
console.log(snapshot.val());
Listening for Real-Time Changes
javascript
useEffect(() => {
const reference = database().ref('/chat/messages');
const onValueChange = reference.on('value', (snapshot) => {
setMessages(Object.values(snapshot.val() || {}));
});
return () => reference.off('value', onValueChange);
}, []);
Updating and Removing Data
javascript
await database().ref('/users/1').update({ online: false });
await database().ref('/users/1').remove();
Realtime Database vs Firestore
Realtime Database offers simpler, faster real-time synchronization for simple data structures, while Firestore provides more powerful querying capabilities and better scalability for complex, structured data.
Common Use Cases
- Live chat applications
- Real-time presence indicators (online/offline status)
- Collaborative, live-updating features
Conclusion
Firebase Realtime Database excels at simple, low-latency real-time synchronization use cases, making it particularly well suited for chat applications and live presence features in React Native apps.
