AkshayChordiya

@Entity(tableName = "users", indices = arrayOf(Index("full_name"), Index("phone_number")))
data class User(
        @PrimaryKey(autoGenerate = true)
        var id: Int = 0,
        @ColumnInfo(name = "full_name")
        var name: String = "",
        @ColumnInfo(name = "phone_number")
        var phoneNumber: String = ""
)

AkshayChordiya

@Entity(tableName = "users", indices = arrayOf(Index("full_name")))
data class User(
        @PrimaryKey(autoGenerate = true)
        var id: Int = 0,
        @ColumnInfo(name = "full_name")
        var name: String = ""
)

AkshayChordiya

@Query("SELECT users.*, city FROM users JOIN addresses ON users.address_id = addresses.id")
fun getUsersWithCity(): LiveData<List<UserWithAddress>>

AkshayChordiya

data class UserWithAddress(
  @Embedded
  var user: User,
  @ColumnInfo(name = "city")
  var city: String? = ""
)

AkshayChordiya

@Entity(tableName = "users", , foreignKeys = arrayOf(
        ForeignKey(entity = Address::class, parentColumns = arrayOf("id"), childColumns = arrayOf("address_id"))
)
data class User(
        @PrimaryKey(autoGenerate = true) 
        var id: Int = 0,
        var name: String = "",
        @ColumnInfo(name = "address_id")
        var address: Long? = null,
)

AkshayChordiya

@Entity(tableName = "addresses")
data class Address(
    @PrimaryKey
    var id: Long = 0,
    var state: String = "",
    var city: String = ""
)

AkshayChordiya

data class Address(
    var state: String = "",
    var city: String = ""
)

AkshayChordiya

@Entity(tableName = "users")
data class User(
        @PrimaryKey(autoGenerate = true) 
        var id: Int = 0,
        var name: String = "",
        @Embedded
        var address: Address
)

AkshayChordiya

// Get instance
database = Room.databaseBuilder(context, AppDatabase::class.java, "app.db")               
               .build();

// Example Usage
val userDao = database.userDao()

AkshayChordiya

@Database(entities = arrayOf(User::class), version = 1)
abstract class AppDatabase : RoomDatabase() {
    abstract fun userDao(): UserDao
}