Professional Android, 4th Edition

9Creating and Using Databases

WHAT'S IN THIS CHAPTER?

• Persisting application data using the Room persistence library
• Using Room to add, modify, and delete saved data
• Querying Room databases and observing query result changes using Live Data
• Creating databases using the SQLite library
• Using the SQLiteOpenHelper to simplify SQLite database access
• Validating database input
• Using Content Values to add, modify, and delete database records
• Querying database records and managing Cursors
• Adding, modifying, and deleting data within a Firebase Database
• Querying and observing changes to a Firebase Database

WROX.COM CODE DOWNLOADS FOR THIS CHAPTER

The code downloads for this chapter are found at www.wrox.com. The code for this chapter is divided into the following major examples:

• Snippets_ch9.zip
• Earthquake_ch9.zip

INTRODUCING STRUCTURED DATA STORAGE IN ANDROID

This chapter introduces structured data storage in Android, starting with the Room persistence library, before investigating the underlying SQLite relational database, and exploring the Firebase Realtime NoSQL Database.

Room provides an abstraction layer over SQLite that allows you to persist your applications data using the powerful SQLite database, while abstracting away the complexity of managing the database itself.

You learn how to define the Room database and how to query it and perform transactions using Data Access Objects (DAO). You also learn how to use Live Data to track changes in query results within your ...