In this first chapter, we accomplished a lot. We started off by looking at the simplest and most efficient data storage method of them all — the SharedPreferences class. We looked at the pros and cons of using a SharedPreferences object in your application, and though the class itself is limited to storing primitive data types, we saw that its use cases are plenty.

Then, we moved up a little in complexity and examined both internal and external storage mechanisms. Though not as intuitive and efficient as a shared preference object, by leveraging internal and external storage, we are capable of storing both much more data and much more complex data (that is, images, media files, and so on). The pros and cons of using internal storage versus external storage are much more subtle and many times are highly phone and hardware dependent. But in any case, this goes to illustrate my earlier point that part of mastering data on Android is being able to analyze the pros and cons of every storage method and intelligently decide the most suitable method for your application's needs.

Finally, we dipped our toes into SQLite databases and looked at how you can override the SQLiteOpenHelper class to create your custom SQLite database and table. From there we saw an example of how to open and retrieve this SQLite database from an Activity class, and subsequently, how to both insert into and retrieve rows from our table. Because of the flexibility of the SQLiteDatabase class, we saw that there were multiple ways for both inserting and retrieving data, allowing those less familiar with SQL to utilize the wrapper methods, while allowing those SQL aficionados to flex their querying prowess by executing raw SQL commands.

In the next chapter, we'll focus on SQLite databases, and attempt to build a much more complex, yet realistic, database schema.