Welcome back! In the previous lessons, you learned how to structure and add data to your Firestore database using collections and documents. Today, we will focus on retrieving data from Firestore. Data retrieval is a fundamental part of working with any database, as it allows you to access and use the information you have stored. In this lesson, we will cover how to fetch a single document by its ID and how to retrieve multiple documents by their IDs. By the end of this session, you will be able to efficiently access the data you need from your Firestore collections.

Retrieving a document from Firestore is straightforward when you know the document's ID. For example, suppose you have a movies collection and want to fetch the document with the ID the-big-new-movie-2016. Here's how you can do it:

Output (example):

If you only need specific fields from the document, you can use the field_paths parameter to select them:

Output (example):