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

Repository

DAO

ViewModel

Database

None

What is the purpose of the 'MainViewModelFactory' class?

To manage database migrations.

To define custom SQL queries.

To create instances of the Room database.

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

None

Which component in Room is responsible for defining SQL queries?

Entity

DAO

ViewModel

Repository

None

Why is 'LiveData' used in Room database queries?

To handle database transactions.

To ensure queries are executed on the main thread.

To observe and automatically update the UI with database changes.

To improve database performance.

None

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

@Dao

@Database

@Entity

@Table

None

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

To enable debugging features.

To ensure the app’s UI remains responsive.

To reduce battery consumption.

To improve network performance.

None

Which library is required for handling asynchronous Room database queries?

Coroutines

Glide

Dagger

Retrofit

None

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

Inserts new records into the database.

Executes a custom SQL query.

Updates existing records in the database.

Deletes records from the database.

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 enable foreign key constraints.

To automatically create entity classes.

None

10.

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

To create UI components.

To abstract data operations and interact with the DAO.

To provide direct access to the database.

To manage API calls.

None

11.

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

runOnUiThread()

AsyncTask()

launch() with Dispatchers.IO

Thread.sleep()

None

12.

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

13.

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

14.

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

To create a backup of database data.

To define database table schemas.

To manage UI theme changes.

To store search results for observed updates.

None

15.

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

By directly instantiating the RoomDatabase class.

By writing raw SQL queries.

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

By creating a custom SQL engine.

None

16.

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.

Automatically updates the database schema without data loss.

Prevents data loss during migrations.

None