Compose Room Database Quiz Pt 2

Welcome to the Room Database Quiz! This quiz will test your knowledge of implementing SQLite-based database storage using the Room persistence library in Android applications. The questions cover various aspects, including setting up a Room database, working with entities, DAOs, repositories, and integrating these with a ViewModel and Jetpack Compose UI. Whether you’re revisiting concepts or testing your understanding, this quiz is designed to help reinforce your learning and ensure you’re ready to build robust data-driven Android apps.

Why might 'autoGenerate = true' be used with the '@PrimaryKey' annotation?

To automatically create entity classes.

To auto-generate primary key values for new records.

To manage schema migrations automatically.

To enable foreign key constraints.

None

Which component is typically responsible for managing the UI state in the Room-based project?

ViewModel

Database

Repository

DAO

None

How can changes to database records be automatically reflected in the UI?

By directly accessing the database in the UI.

By setting up manual refresh methods in the DAO.

By using ‘LiveData’ and observing it in the ViewModel.

By storing data in SharedPreferences.

None

What is the role of a Repository class when working with Room databases?

To abstract data operations and interact with the DAO.

To provide direct access to the database.

To manage API calls.

To create UI components.

None

Which library is required for handling asynchronous Room database queries?

Dagger

Coroutines

Retrofit

Glide

None

Which component in Room is responsible for defining SQL queries?

DAO

ViewModel

Repository

Entity

None

Why is it important to avoid performing database operations on the main thread?

To reduce battery consumption.

To improve network performance.

To ensure the app’s UI remains responsive.

To enable debugging features.

None

What is the purpose of the 'MainViewModelFactory' class?

To provide a factory for creating ‘MainViewModel’ instances with an application context.

To create instances of the Room database.

To manage database migrations.

To define custom SQL queries.

None

What does the '@Insert' annotation in a DAO do?

Deletes records from the database.

Inserts new records into the database.

Updates existing records in the database.

Executes a custom SQL query.

None

10.

What is the purpose of using 'MutableLiveData' in a repository?

To manage UI theme changes.

To create a backup of database data.

To define database table schemas.

To store search results for observed updates.

None

11.

Which function is used to prevent blocking the main thread during database operations?

launch() with Dispatchers.IO

Thread.sleep()

runOnUiThread()

AsyncTask()

None

12.

Why is 'LiveData' used in Room database queries?

To improve database performance.

To handle database transactions.

To ensure queries are executed on the main thread.

To observe and automatically update the UI with database changes.

None

13.

What should be done to use the Database Inspector with a running Room database app?

Connect to a physical device.

Run the app on an emulator or connected device.

Enable ProGuard settings.

Enable a debug mode in Room configuration.

None

14.

How is a Room database instance created in the RoomDemo project?

By directly instantiating the RoomDatabase class.

By writing raw SQL queries.

By extending the RoomDatabase class and using ‘Room.databaseBuilder’.

By creating a custom SQL engine.

None

15.

Which annotation is used to define a class as an entity in Room?

@Table

@Database

@Dao

@Entity

None

16.

What does the 'fallbackToDestructiveMigration()' method do in Room?

Backs up the database before migration.

Automatically updates the database schema without data loss.

Deletes and recreates the database if a migration is not found.

Prevents data loss during migrations.

None