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.

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

By directly instantiating the RoomDatabase class.

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

By writing raw SQL queries.

By creating a custom SQL engine.

None

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

To ensure the app’s UI remains responsive.

To enable debugging features.

To reduce battery consumption.

To improve network performance.

None

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

To provide direct access to the database.

To manage API calls.

To abstract data operations and interact with the DAO.

To create UI components.

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 directly accessing the database in the UI.

By setting up manual refresh methods in the DAO.

None

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

To store search results for observed updates.

To manage UI theme changes.

To define database table schemas.

To create a backup of database data.

None

Why is 'LiveData' used in Room database queries?

To observe and automatically update the UI with database changes.

To ensure queries are executed on the main thread.

To handle database transactions.

To improve database performance.

None

What is the purpose of the 'MainViewModelFactory' class?

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

To define custom SQL queries.

To manage database migrations.

To create instances of the Room database.

None

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

Enable ProGuard settings.

Connect to a physical device.

Run the app on an emulator or connected device.

Enable a debug mode in Room configuration.

None

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

Backs up the database before migration.

Prevents data loss during migrations.

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

Automatically updates the database schema without data loss.

None

10.

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

Inserts new records into the database.

Deletes records from the database.

Executes a custom SQL query.

Updates existing records in the database.

None

11.

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

@Dao

@Table

@Entity

@Database

None

12.

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

Repository

ViewModel

Database

DAO

None

13.

Which component in Room is responsible for defining SQL queries?

DAO

Entity

Repository

ViewModel

None

14.

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

launch() with Dispatchers.IO

AsyncTask()

Thread.sleep()

runOnUiThread()

None

15.

Which library is required for handling asynchronous Room database queries?

Dagger

Coroutines

Glide

Retrofit

None

16.

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

To enable foreign key constraints.

To automatically create entity classes.

To auto-generate primary key values for new records.

To manage schema migrations automatically.

None