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.

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

@Table

@Dao

@Database

@Entity

None

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

ViewModel

Database

DAO

Repository

None

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

To improve network performance.

To enable debugging features.

To ensure the app’s UI remains responsive.

To reduce battery consumption.

None

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

By writing raw SQL queries.

By directly instantiating the RoomDatabase class.

By creating a custom SQL engine.

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

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

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

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

To create a backup of database data.

To store search results for observed updates.

To define database table schemas.

To manage UI theme changes.

None

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

To automatically create entity classes.

To manage schema migrations automatically.

To enable foreign key constraints.

To auto-generate primary key values for new records.

None

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

Prevents data loss during migrations.

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.

None

10.

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

Run the app on an emulator or connected device.

Enable a debug mode in Room configuration.

Enable ProGuard settings.

Connect to a physical device.

None

11.

Which component in Room is responsible for defining SQL queries?

DAO

ViewModel

Entity

Repository

None

12.

What is the purpose of the 'MainViewModelFactory' class?

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

To define custom SQL queries.

To manage database migrations.

To create instances of the Room database.

None

13.

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

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

By directly accessing the database in the UI.

By storing data in SharedPreferences.

By setting up manual refresh methods in the DAO.

None

14.

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

Deletes records from the database.

Executes a custom SQL query.

Updates existing records in the database.

Inserts new records into the database.

None

15.

Which library is required for handling asynchronous Room database queries?

Retrofit

Coroutines

Glide

Dagger

None

16.

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

Thread.sleep()

AsyncTask()

runOnUiThread()

launch() with Dispatchers.IO

None