Murphy M. Elements of Android Room Version 0.9 2021

Textbook in PDF format

Storing data locally is a key part of many Android apps. SQLite is built into Android, but the low-level API that the Android SDK provides is a bit clunky to use.
Google’s solution for that is Room, an object wrapper around that API. This gives us a cleaner, type-safe, reactive API for our database operations. Room is part of the Android Jetpack, and so it is a key element of Google’s recommended “stack” of technologies for building Android apps.
This book explores Room, starting with basic stuff like:
Adding Room to your app
Defining your entities and data access operation (DAO) APIs
Testing your database I/O
Using Room with Kotlin coroutines, LiveData, and RxJava
Migrating your database schema as your app evolves
It also gets into more elaborate scenarios, such as using SQLCipher for Android for encrypting your Room database