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

To ensure the app’s UI remains responsive.

To reduce battery consumption.

To enable debugging features.

To improve network performance.

None

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

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

By writing raw SQL queries.

By creating a custom SQL engine.

By directly instantiating the RoomDatabase class.

None

What is the purpose of the 'MainViewModelFactory' class?

To create instances of the Room database.

To manage database migrations.

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

To define custom SQL queries.

None

Which component in Room is responsible for defining SQL queries?

Repository

DAO

ViewModel

Entity

None

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

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

Automatically updates the database schema without data loss.

Prevents data loss during migrations.

Backs up the database before migration.

None

Which library is required for handling asynchronous Room database queries?

Dagger

Glide

Coroutines

Retrofit

None

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

By directly accessing the database 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.

None

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

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

Executes a custom SQL query.

Inserts new records into the database.

Deletes records from the database.

Updates existing records in the database.

None

10.

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

To manage API calls.

To create UI components.

To abstract data operations and interact with the DAO.

To provide direct access to the database.

None

11.

Why is 'LiveData' used in Room database queries?

To handle database transactions.

To observe and automatically update the UI with database changes.

To ensure queries are executed on the main thread.

To improve database performance.

None

12.

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

@Entity

@Dao

@Table

@Database

None

13.

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

DAO

Database

Repository

ViewModel

None

14.

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

Enable a debug mode in Room configuration.

Enable ProGuard settings.

Connect to a physical device.

Run the app on an emulator or connected device.

None

15.

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

To enable foreign key constraints.

To manage schema migrations automatically.

To auto-generate primary key values for new records.

To automatically create entity classes.

None

16.

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

Thread.sleep()

runOnUiThread()

AsyncTask()

launch() with Dispatchers.IO

None