@firebase/firestore

Adding Data

This feature allows you to add new documents to your Firestore database. The code sample demonstrates adding a new user with name and age fields to a 'users' collection.

db.collection('users').add({
  name: 'Ada Lovelace',
  age: 36
});

Reading Data

This feature enables reading documents from your Firestore database. The code sample shows how to fetch a document by its ID from the 'users' collection and log its data.

db.collection('users').doc('userId').get().then((doc) => {
  if (doc.exists) {
    console.log('Document data:', doc.data());
  } else {
    console.log('No such document!');
  }
});

Listening for Real-time Updates

This feature provides real-time updates on data changes. The code sample demonstrates setting up a listener on a user document to log updates in real-time.

db.collection('users').doc('userId')
  .onSnapshot((doc) => {
    console.log('Current data: ', doc.data());
  });

Querying Data

This feature allows querying documents based on certain conditions. The code sample shows how to query all users older than 18 years and log their data.

db.collection('users').where('age', '>', 18)
  .get()
  .then((querySnapshot) => {
    querySnapshot.forEach((doc) => {
      console.log(doc.id, ' => ', doc.data());
    });
  });