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?

@Dao

@Entity

@Table

@Database

None

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

To manage API calls.

To abstract data operations and interact with the DAO.

To provide direct access to the database.

To create UI components.

None

Which library is required for handling asynchronous Room database queries?

Dagger

Coroutines

Retrofit

Glide

None

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

Prevents data loss during migrations.

Automatically updates the database schema without data loss.

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

Backs up the database before migration.

None

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

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

By storing data in SharedPreferences.

By setting up manual refresh methods in the DAO.

By directly accessing the database in the UI.

None

What is the purpose of the 'MainViewModelFactory' class?

To define custom SQL queries.

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

To create instances of the Room database.

To manage database migrations.

None

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

Executes a custom SQL query.

Updates existing records in the database.

Inserts new records into the database.

Deletes records from the database.

None

Which component in Room is responsible for defining SQL queries?

Entity

Repository

DAO

ViewModel

None

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

To store search results for observed updates.

To define database table schemas.

To create a backup of database data.

To manage UI theme changes.

None

10.

Why is 'LiveData' used in Room database queries?

To ensure queries are executed on the main thread.

To handle database transactions.

To observe and automatically update the UI with database changes.

To improve database performance.

None

11.

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

To improve network performance.

To reduce battery consumption.

To ensure the app’s UI remains responsive.

To enable debugging features.

None

12.

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

To auto-generate primary key values for new records.

To manage schema migrations automatically.

To automatically create entity classes.

To enable foreign key constraints.

None

13.

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

Database

DAO

ViewModel

Repository

None

14.

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

Thread.sleep()

runOnUiThread()

AsyncTask()

launch() with Dispatchers.IO

None

15.

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

Enable a debug mode in Room configuration.

Connect to a physical device.

Enable ProGuard settings.

Run the app on an emulator or connected device.

None

16.

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

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

By creating a custom SQL engine.

By directly instantiating the RoomDatabase class.

By writing raw SQL queries.

None