Firebase V9 Firestore UPDATE Document Data Using updateDoc()

There are two methods you can use to update an existing document in Firebase Version 9 Cloud Firestore.

setDoc()
updateDoc() → you’re here

Using updateDoc(), you can only update the document field of an existing document in the Firestore Database which can be:

• Adding a new document field
• Updating a value of an existing document field
• Deleting a Document Field

Add A New Document Field Using updateDoc()

Here is a sample document inside the cities collection from the Cloud Firestore Database.

In order to update an existing document using the updateDoc()method, we need three methods:

• getDatabase() → where we want to update a document.
• doc() → where we’ll be passing references of database, collection, and ID of a document that we want to update one of its fields.
• updateDoc() → where we actually pass new data that we want to replace along with the doc() method.