ROOM TypeConverter

 

@Entity(tableName = "text_table")
data class TextEntity (

    @PrimaryKey(autoGenerate = true)
    @ColumnInfo(name = "id")
    var id : Int,

    @ColumnInfo(name = "text")
    var text : String,

    @ColumnInfo(name = "currentDate")
    var currentDate : Date

//    @Embedded
//    var testDataset : testDataSet

)


class DateConverters{

    @TypeConverter
    fun fromTimestamp(value: Long): Date {
        return Date(value)
    }

    @TypeConverter
    fun dateToTimestamp(date: Date): Long {
        return date.time
    }

}

 

@Database(
    entities = [TextEntity::class],
    version = 33,
    exportSchema = false
)
@TypeConverters(DateConverters::class)
abstract class TextDatabase : RoomDatabase() {

    abstract fun textDao() : TextDao

    companion object {

        @Volatile
        private var INSTANCE : TextDatabase? = null

        fun getDatabase(
            context : Context
        ) : TextDatabase {
            return INSTANCE ?: synchronized(this){
                val instance = Room.databaseBuilder(
                    context.applicationContext,
                    TextDatabase::class.java,
                    "text_database"
                )
                    .fallbackToDestructiveMigration()
//                    .addMigrations(MIGRATION_1_2)
                    .build()
                INSTANCE = instance
                instance
            }
        }

        val MIGRATION_1_2 = object : Migration(26, 27) {
            override fun migrate(database: SupportSQLiteDatabase) {
                database.execSQL("CREATE TABLE `text_table3` (`id3` INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, `text3` TEXT NOT NULL)")
//                database.execSQL("DROP TABLE `text_table3`")
            }
        }
    }

}

 

 

 

 

 

 

 

 

 

- 참조

 

https://developer.android.com/training/data-storage/room/referencing-data?hl=ko 

Room을 사용하여 복잡한 데이터 참조  |  Android 개발자  |  Android Developers