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

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.

Prevents data loss during migrations.

None

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

Updates existing records in the database.

Executes a custom SQL query.

Deletes records from the database.

Inserts new records into the database.

None

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

To auto-generate primary key values for new records.

To enable foreign key constraints.

To automatically create entity classes.

To manage schema migrations automatically.

None

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

@Database

@Table

@Entity

@Dao

None

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

To ensure the app’s UI remains responsive.

To improve network performance.

To reduce battery consumption.

To enable debugging features.

None

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

Enable a debug mode in Room configuration.

Run the app on an emulator or connected device.

Enable ProGuard settings.

Connect to a physical device.

None

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

launch() with Dispatchers.IO

runOnUiThread()

Thread.sleep()

AsyncTask()

None

Why is 'LiveData' used in Room database queries?

To improve database performance.

To ensure queries are executed on the main thread.

To observe and automatically update the UI with database changes.

To handle database transactions.

None

Which library is required for handling asynchronous Room database queries?

Coroutines

Retrofit

Glide

Dagger

None

10.

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

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

By setting up manual refresh methods in the DAO.

By directly accessing the database in the UI.

By storing data in SharedPreferences.

None

11.

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

12.

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

To store search results for observed updates.

To manage UI theme changes.

To create a backup of database data.

To define database table schemas.

None

13.

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

14.

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

To manage API calls.

To provide direct access to the database.

To abstract data operations and interact with the DAO.

To create UI components.

None

15.

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

DAO

ViewModel

Repository

Database

None

16.

Which component in Room is responsible for defining SQL queries?

Entity

Repository

ViewModel

DAO

None