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?

@Entity

@Database

@Table

@Dao

None

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

Repository

ViewModel

Database

DAO

None

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

To enable debugging features.

To reduce battery consumption.

To improve network performance.

To ensure the app’s UI remains responsive.

None

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

Inserts new records into the database.

Executes a custom SQL query.

Deletes records from the database.

Updates existing records in the database.

None

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

launch() with Dispatchers.IO

runOnUiThread()

Thread.sleep()

AsyncTask()

None

Why is 'LiveData' used in Room database queries?

To ensure queries are executed on the main thread.

To improve database performance.

To handle database transactions.

To observe and automatically update the UI with database changes.

None

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

To enable foreign key constraints.

To manage schema migrations automatically.

To automatically create entity classes.

To auto-generate primary key values for new records.

None

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

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

By directly instantiating the RoomDatabase class.

By creating a custom SQL engine.

By writing raw SQL queries.

None

Which library is required for handling asynchronous Room database queries?

Coroutines

Retrofit

Dagger

Glide

None

10.

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 create UI components.

To manage API calls.

None

11.

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

To create a backup of database data.

To manage UI theme changes.

To store search results for observed updates.

To define database table schemas.

None

12.

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

Backs up the database before migration.

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

Prevents data loss during migrations.

Automatically updates the database schema without data loss.

None

13.

Which component in Room is responsible for defining SQL queries?

Repository

DAO

Entity

ViewModel

None

14.

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

Enable ProGuard settings.

Run the app on an emulator or connected device.

Connect to a physical device.

Enable a debug mode in Room configuration.

None

15.

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

By setting up manual refresh methods in the DAO.

By storing data in SharedPreferences.

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

By directly accessing the database in the UI.

None

16.

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 define custom SQL queries.

To manage database migrations.

None