Android Data Storage Flashcards
6 cards from real Android Development practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Android Data Storage flashcards as text
Which Room annotation defines a foreign key relationship between two entities?
Answer: @ForeignKey inside @Entity
The @ForeignKey annotation within @Entity defines referential integrity constraints between two Room database tables.
How do you perform a database migration in Room when the schema changes?
Answer: By providing a Migration object with SQL migration scripts
Room requires you to provide a Migration object containing the SQL statements needed to transform the old schema to the new one.
What return type should a Room DAO method use to observe database changes reactively?
Answer: Both A and B
Room supports both Flow and LiveData as return types for DAO queries, enabling reactive observation of database changes.
Which method is used to get or create an instance of a Room database?
Answer: Room.databaseBuilder()
Room.databaseBuilder() creates or opens a Room database with the specified context, class, and database name.
What is the purpose of the @TypeConverter annotation in Room?
Answer: To convert non-primitive types that Room cannot store natively
@TypeConverter marks methods that tell Room how to convert a custom type to and from a type it can store in SQLite.
Which file access mode should be used to append data to a file in Android?
Answer: MODE_APPEND
MODE_APPEND opens the file in append mode so new data is added to the end rather than overwriting existing content.