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.

What is the purpose of the 'MainViewModelFactory' class?

To manage database migrations.

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

To define custom SQL queries.

To create instances of the Room database.

None

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

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

@Table

@Database

@Entity

@Dao

None

Why is 'LiveData' used in Room database queries?

To improve database performance.

To observe and automatically update the UI with database changes.

To handle database transactions.

To ensure queries are executed on the main thread.

None

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

To store search results for observed updates.

To define database table schemas.

To manage UI theme changes.

To create a backup of database data.

None

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

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

Which library is required for handling asynchronous Room database queries?

Retrofit

Glide

Dagger

Coroutines

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

10.

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

Prevents data loss during migrations.

Automatically updates the database schema without data loss.

Backs up the database before migration.

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

None

11.

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

To improve network performance.

To enable debugging features.

To reduce battery consumption.

To ensure the app’s UI remains responsive.

None

12.

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

Repository

Database

DAO

ViewModel

None

13.

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

By writing raw SQL queries.

By creating a custom SQL engine.

By directly instantiating the RoomDatabase class.

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

None

14.

Which component in Room is responsible for defining SQL queries?

Entity

ViewModel

DAO

Repository

None

15.

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

Updates existing records in the database.

Inserts new records into the database.

Deletes records from the database.

Executes a custom SQL query.

None

16.

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

AsyncTask()

launch() with Dispatchers.IO

Thread.sleep()

runOnUiThread()

None