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

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

Thread.sleep()

launch() with Dispatchers.IO

AsyncTask()

runOnUiThread()

None

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

Enable ProGuard settings.

Enable a debug mode in Room configuration.

Run the app on an emulator or connected device.

Connect to a physical device.

None

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

Repository

ViewModel

Database

DAO

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 setting up manual refresh methods in the DAO.

By directly accessing the database in the UI.

None

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

By creating a custom SQL engine.

By directly instantiating the RoomDatabase class.

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

By writing raw SQL queries.

None

Which library is required for handling asynchronous Room database queries?

Coroutines

Glide

Dagger

Retrofit

None

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

To manage UI theme changes.

To store search results for observed updates.

To create a backup of database data.

To define database table schemas.

None

Which component in Room is responsible for defining SQL queries?

ViewModel

DAO

Entity

Repository

None

10.

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

@Entity

@Dao

@Database

@Table

None

11.

What is the purpose of the 'MainViewModelFactory' class?

To define custom SQL queries.

To manage database migrations.

To create instances of the Room database.

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

None

12.

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

To automatically create entity classes.

To manage schema migrations automatically.

To auto-generate primary key values for new records.

To enable foreign key constraints.

None

13.

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

Backs up the database before migration.

Automatically updates the database schema without data loss.

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

Prevents data loss during migrations.

None

14.

Why is 'LiveData' used in Room database queries?

To ensure queries are executed on the main thread.

To improve database performance.

To observe and automatically update the UI with database changes.

To handle database transactions.

None

15.

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

Inserts new records into the database.

Executes a custom SQL query.

Deletes records from the database.

Updates existing records in the database.

None

16.

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

To manage API calls.

To abstract data operations and interact with the DAO.

To provide direct access to the database.

To create UI components.

None