How to add an entry into Room using Coroutines-CodePudding

I'm trying to add an entry into local DB but it's not working for me. It says unresolved reference.

RoomClass.kt

@Database(entities = [ApodEntity::class], version = 1, exportSchema = false)
abstract class AppDatabase : RoomDatabase() {
abstract fun appListDao(): AppDao
}

Dao.kt

 @Dao
interface AppDao {

@Insert()
fun saveFavorites(item: AppEntity)
}

I'm trying to insert using an adapter:

GlobalScope.launch {
             AppDatabase.appListDao().saveFavorites(entity)
            }

But here appListDao called as unknown reference. Hope my query is cleared. Thanks in advance.

CodePudding user response：

It's because of that you must create instance of AppDabase and then on instance of it call the dao function like this:

create a file DatabaseSinglton.kt

object DatabaseSingleton {

    var database: AppDatabase? = null

    fun getAppDatabase(context: Context): AppDatabase {
        return if (database == null) {
            database = Room.databaseBuilder(
                context,
                AppDatabase::class.java,
                "AppDatabase"
            ).build()

            database!!
        } else {
            database!!
        }
    }
}

and when your code must be change to this:

GlobalScope.launch {
    DatabaseSingleton.getAppDatabase(
        context
    ).appListDao().saveFavorites(entity)
}