Room basic sample in Kotlin

build.gradle

apply plugin: 'kotlin-kapt'

dependencies {
    implementation "androidx.room:room-ktx:2.2.5"
    kapt "androidx.room:room-compiler:2.2.5"
}

PeopleDb.kt

import androidx.room.Database
import androidx.room.RoomDatabase

@Database(
    entities = [Person::class],
    version = 1
)
abstract class PeopleDb : RoomDatabase() {

    abstract fun personDao(): PersonDao
}

Person.kt

import androidx.room.Entity
import androidx.room.PrimaryKey

@Entity
data class Person(
    @PrimaryKey(autoGenerate = true)
    val id: Int,
    val name: String,
    val age: Int,
    val address: String
)

PersonDao.kt

import androidx.room.*

@Dao
interface PersonDao {

    @Query("SELECT * from Person")
    suspend fun getAll(): List<Person>

    @Query("SELECT * FROM Person WHERE id = :id")
    suspend fun findById(id: Int): Person

    @Insert(onConflict = OnConflictStrategy.IGNORE)
    suspend fun insert(people: List<Person>)

    @Update
    suspend fun update(person: Person)

    @Delete
    suspend fun delete(person: Person)
}

RoomApp.kt

import android.app.Application
import androidx.room.Room

class RoomApp : Application() {

    val room: PeopleDb = Room
        .databaseBuilder(this, PeopleDb::class.java, "people")
        .build()
}