Learning Android

Chapter 9. The Database

The Android system uses databases to store useful information that needs to be persisted even when the user kills the app or even shuts down the device and powers it back on. The data includes contacts, system settings, bookmarks, and so on.

So, why use a database in a mobile application? After all, isn’t it better to keep our data in a cloud where it’s always backed up instead of storing it in a mobile device that is easily lost or damaged?

A database in a mobile device is very useful as a supplement to the online world. Although in many cases it is much better to count on the data living in the cloud, it is useful to store it locally in order to access it more quickly and have it available even when the network is not available. In this case, we are using a local database as a cache. This is also how we use it in our Yamba application.

In this chapter, you will learn how Android supports databases. You will learn to create and use a database inside the Yamba application to store our status updates locally. Local data will help Yamba display statuses to the user quickly, without having to wait for the network to provide the data. Our service will run in the background and periodically update the database so that the data is relatively fresh. This will improve the overall user experience of the application.

About SQLite

SQLite is an open source database that has been around for a long time, is quite stable, and is popular on many small devices, including Android. ...