My data in Database are deleted everytime I am killing the app?

Question

In my android app, I am storing data in database using Room Database library.I can store and get data in a single session.There is no problem in that. The problem is when I close the app and open again I am not getting the data stored in the local database.Those data are deleted.

I've searched in google and some of them said create room data database instance using databaseBuilder.But I am using that only.but I am getting this error.

This is my instance initialization.

This is my AppDtabase class ;

@Database(entities = {SelectedBuilding.class}, exportSchema =true,  version=2)
public abstract class AppDatabase extends RoomDatabase {
    private static AppDatabase INSTANCE;

    public abstract SelectedBuildingDao myDao();

    public static AppDatabase getAppDatabase(Context context){
        if (INSTANCE==null){
            INSTANCE= Room.databaseBuilder(context.getApplicationContext(),AppDatabase.class,"Selected_buildings")
                    .addMigrations(MIGRATION_1_2)
                    .build();
        }
        return INSTANCE;
    }

    public static void destroyInstance(){
        INSTANCE=null;
    }

    static final Migration MIGRATION_1_2 = new Migration(1, 2) {
        @Override
        public void migrate(SupportSQLiteDatabase database) {
            database.execSQL("ALTER TABLE selected_building ADD COLUMN Building_Id TEXT");
        }
    };



}

 INSTANCE= Room.databaseBuilder(context.getApplicationContext(),AppDatabase.class,"Selected_area").build();

Can anyone help me to solve this issue? Thanks in Advance.