Room database setup in Android Kotlin - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is Room in Android development?

Room is a library that provides an easy way to work with SQLite databases by using simple annotations and abstracting boilerplate code.

beginner

Which annotation is used to define an entity (table) in Room?

The @Entity annotation is used to mark a Kotlin data class as a table in the Room database.

beginner

What is the role of the @Dao interface in Room?

The @Dao interface defines methods to access the database, such as queries, inserts, updates, and deletes.

intermediate

How do you create the Room database instance in your app?

You create the database instance using Room.databaseBuilder(context, YourDatabase::class.java, "database_name").build() inside a singleton or application class.

intermediate

Why should Room database operations be done off the main thread?

Because database operations can be slow, doing them on the main thread can freeze the UI. Room enforces this by throwing an error if you try to do heavy operations on the main thread.

Which annotation marks a data class as a table in Room?

A @Database

B @Dao

C @Table

D @Entity

The @Entity annotation is used to define a table in Room.

What does @Dao stand for in Room?

A Data Access Object

B Database Access Operation

C Data Annotation Object

D Direct Access Operation

@Dao stands for Data Access Object, which defines database interaction methods.

How do you create a Room database instance?

A new RoomDatabase()

B Room.databaseBuilder(context, DbClass::class.java, "name").build()

C Room.createDatabase()

D DatabaseBuilder.create()

Room.databaseBuilder() is the correct way to create a database instance.

Which of these is NOT a recommended practice with Room?

A Running queries on the main thread

B Using @Entity for tables

C Defining DAO interfaces

D Using LiveData with queries

Running queries on the main thread can freeze the UI and is not recommended.

What is the purpose of the @Database annotation?

A To create tables automatically

B To mark a class as a DAO

C To define the database holder and list entities

D To run queries

@Database annotation defines the database class and its entities.

Explain the main components needed to set up a Room database in an Android app.

Think about the classes and annotations you need to define tables, access data, and create the database.

Why is it important to avoid running Room database operations on the main thread? How can you handle this?

Consider what happens if the app waits too long for data and how Kotlin helps with background work.