For the More Curious: More Databases
by Kristin Marsicano, Chris Stewart, Bill Phillips
Android Programming: The Big Nerd Ranch Guide, Third Edition
- Cover
- Learning Android
- The Necessary Tools
- 1. Your First Android Application
- 2. Android and Model-View-Controller
- 3. The Activity Lifecycle
- 4. Debugging Android Apps
- 5. Your Second Activity
- 6. Android SDK Versions and Compatibility
- 7. UI Fragments and the Fragment Manager
- The Need for UI Flexibility
- Introducing Fragments
- Starting CriminalIntent
- Hosting a UI Fragment
- Creating a UI Fragment
- Adding a UI Fragment to the FragmentManager
- Application Architecture with Fragments
- For the More Curious: Fragments and the Support Library
- For the More Curious: Why Support Fragments Are Superior
- 8. Displaying Lists with RecyclerView
- 9. Creating User Interfaces with Layouts and Widgets
- 10. Using Fragment Arguments
- 11. Using ViewPager
- 12. Dialogs
- 13. The Toolbar
- 14. SQLite Databases
- 15. Implicit Intents
- 16. Taking Pictures with Intents
- 17. Two-Pane Master-Detail Interfaces
- 18. Localization
- 19. Accessibility
- 20. Data Binding and MVVM
- 21. Unit Testing and Audio Playback
- Creating a SoundPool
- Loading Sounds
- Playing Sounds
- Test Dependencies
- Creating a Test Class
- Setting Up Your Test
- Writing Tests
- Data Binding Callbacks
- Unloading Sounds
- Rotation and Object Continuity
- For the More Curious: Whether to Retain
- For the More Curious: Espresso and Integration Testing
- For the More Curious: Mocks and Testing
- Challenge: Playback Speed Control
- 22. Styles and Themes
- 23. XML Drawables
- 24. More About Intents and Tasks
- 25. HTTP and Background Tasks
- Creating PhotoGallery
- Networking Basics
- Using AsyncTask to Run on a Background Thread
- You and Your Main Thread
- Fetching JSON from Flickr
- From AsyncTask Back to the Main Thread
- Cleaning Up AsyncTasks
- For the More Curious: More on AsyncTask
- For the More Curious: Alternatives to AsyncTask
- Challenge: Gson
- Challenge: Paging
- Challenge: Dynamically Adjusting the Number of Columns
- 26. Loopers, Handlers, and HandlerThread
- Preparing RecyclerView to Display Images
- Downloading Lots of Small Things
- Communicating with the Main Thread
- Assembling a Background Thread
- Messages and Message Handlers
- For the More Curious: AsyncTasks vs Threads
- For the More Curious: Solving the Image Downloading Problem
- For the More Curious: StrictMode
- Challenge: Preloading and Caching
- 27. Search
- 28. Background Services
- Creating an IntentService
- What Services Are For
- Looking for New Results
- Delayed Execution with AlarmManager
- Controlling Your Alarm
- Notifications
- Challenge: Notifications on Android Wear
- For the More Curious: Service Details
- For the More Curious: JobScheduler and JobServices
- Challenge: Using JobService on Lollipop
- For the More Curious: Sync Adapters
- 29. Broadcast Intents
- 30. Browsing the Web and WebView
- 31. Custom Views and Touch Events
- 32. Property Animation
- 33. Locations and Play Services
- Locations and Libraries
- Creating Locatr
- Play Services and Location Testing on Emulators
- Building Out Locatr
- Setting Up Google Play Services
- Using Google Play Services
- Flickr Geosearch
- Getting a Location Fix
- Asking for Permission at Runtime
- Find and Display an Image
- Challenge: Permissions Rationale
- Challenge: Progress
- 34. Maps
- 35. Material Design
- 36. Afterword
- Index
For the sake of space and simplicity, we do not go into all the details you might see in a professional app’s application database here. There is a reason people resort to tools like ORMs: This stuff can get complicated.
For a more substantial application, you will want to look into adding the following to your database and your description of it:
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Data types on columns. Technically, SQLite does not have typed columns, so you can get by without them. Giving SQLite hints is kinder, though.
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Indexes. Queries against columns with appropriate indexes are much faster than columns without them.
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Foreign keys. Your database here only has one table, but associated data would need foreign key constraints, too.
There are also deeper performance considerations to dive into. Your app creates a new list of all-new Crime objects every time you query the database. A high-performance app would optimize this by recycling instances of Crime or by treating them like an in-memory object store (like you did before this chapter). That ends up being quite a bit more code, so this is another problem ORMs often try to solve.
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