Android Development Android Data Storage 2

Question 1

Which Room annotation defines a foreign key relationship between two entities?

Accepted Answer

@ForeignKey inside @Entity

Answer

@Relation

Answer

@Join

Answer

@Reference

Question 2

How do you perform a database migration in Room when the schema changes?

Accepted Answer

By providing a Migration object with SQL migration scripts

Answer

By deleting and recreating the database

Answer

By using @SchemaVersion annotation

Answer

Room handles migrations automatically

Question 3

What return type should a Room DAO method use to observe database changes reactively?

Accepted Answer

Both A and B

Answer

Flow<T>

Answer

LiveData<T>

Answer

Observable<T>

Question 4

Which method is used to get or create an instance of a Room database?

Accepted Answer

Room.databaseBuilder()

Answer

RoomDatabase.create()

Answer

Room.getInstance()

Answer

RoomDatabase.build()

Question 5

What is the purpose of the @TypeConverter annotation in Room?

Accepted Answer

To convert non-primitive types that Room cannot store natively

Answer

To convert between database versions

Answer

To transform query results

Answer

To change column data types

Question 6

Which file access mode should be used to append data to a file in Android?

Accepted Answer

MODE_APPEND

Answer

MODE_PRIVATE

Answer

MODE_WORLD_READABLE

Answer

MODE_WRITE_ONLY