"No such column found" with multiple Loader in LoaderManager and MediaStore

Question

From the title of a music, a try toget the corresponding Artist, ALbum's name and Album's Cover. I use LoaderManager and CursorLoader. When the Activity is created I lunch the loader with getLoaderManager().initLoader(1, null, this). Here is the code of my loader:

On Create Loader

static final String[] PLAYER_SUMMARY_PROJECTION = { MediaStore.Audio.Media._ID, MediaStore.Audio.Media.TITLE, MediaStore.Audio.Media.ARTIST, MediaStore.Audio.Media.ALBUM};
    static final String[] PLAYER_COVER_SUMMARY_PROJECTION = { MediaStore.Audio.Albums.ALBUM_ID, MediaStore.Audio.Albums.ALBUM_ART, MediaStore.Audio.Albums.ALBUM};

    public Loader<Cursor> onCreateLoader(int id, Bundle arg1) {
        CursorLoader loader;    

    if(id==1){

        String where = android.provider.MediaStore.Audio.Media.TITLE
                  + "=?";
        String whereVal[] = {dataalbumsTrackRequested};
        loader = new CursorLoader(getActivity(), MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,  
        PLAYER_SUMMARY_PROJECTION, where, whereVal,null); }

    else{

         String where2 = android.provider.MediaStore.Audio.Media.ALBUM
          + "=?";
         String whereVal2[] = {album};
         loader = new CursorLoader(getActivity(), MediaStore.Audio.Albums.EXTERNAL_CONTENT_URI,  
         PLAYER_COVER_SUMMARY_PROJECTION, where2, whereVal2,null);  }

    return loader;

    }

On Load Finish

public void onLoadFinished(Loader<Cursor> loader, Cursor cursor) {

     if(loader.getId()==1){

     //Fill the text view with their value

     //Set Title
     String title =cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.TITLE));
     TextView titleView = (TextView)getView().findViewById(R.id.musicTitle);
     titleView.setText(title);

     //Set Artist
     String artist =cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.ARTIST));
     TextView artistView = (TextView)getView().findViewById(R.id.artistName);
     if (artist.equals("<unknown>")){artistView.setText(R.string.unknown_album);}
     else { artistView.setText(artist);}

     //Set Album
     album =cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.ALBUM));
     TextView albumView = (TextView)getView().findViewById(R.id.albumTitle);
     if (album.equals("<unknown>")){albumView.setText(R.string.unknown_album);}
     else { albumView.setText(album);}

             }

    else {   


     ImageView coverView = (ImageView)getView().findViewById(R.id.playerCoverView);

     if (cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Albums.ALBUM_ART)).equals(null)){
            //if no cover returned, display the by default (empty) cover
            coverView.setImageResource(R.drawable.listcoverthumbnail);}

     else{
            Bitmap coverImage = BitmapFactory.decodeFile(cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Albums.ALBUM_ART)));
                    coverView.setImageBitmap(coverImage);}

      getLoaderManager().initLoader(2, null, this);
  }

The variable album is defined for the whole class and dataalbumsTrackRequested is a String equal to the title of the album desired.

The app crashes and I get :

06-19 16:21:42.720: E/AndroidRuntime(6516): Caused by: android.database.sqlite.SQLiteException: no such column: album_art: , while compiling: SELECT album_id, album_art, album FROM audio WHERE (album=?)

If I remove the second Loader (with Id=2), then of course the cover is not display, but the app doesn't crash. So the problem comes from the second Loader.

What am I doing wrong ? I'm sure the colomn album_art exist as I've already achieved to get the cover like this in one of my other app. But here, I can't find where the bug comes from. Is it because I use multiple Loaders ?

Answer 1

Ok, problem solved.

1) In the second loader, I was using MediaStore.Audio.Media.ALBUM instead of MediaStore.Audio.albums.ALBUM

2) My projection was PLAYER_COVER_SUMMARY_PROJECTION = { MediaStore.Audio.Albums.ALBUM_ID, MediaStore.Audio.Albums.ALBUM_ART, MediaStore.Audio.Albums.ALBUM}

instead of PLAYER_COVER_SUMMARY_PROJECTION = { MediaStore.Audio.Albums._ID, MediaStore.Audio.Albums.ALBUM_ART, MediaStore.Audio.Albums.ALBUM};

Then if you get the error 06-19 19:29:18.115: E/AndroidRuntime(22943): android.database.CursorIndexOutOfBoundsException: Index -1 requested, with a size of 1, I solved it with cursor.move(cursor.getPosition()+2) in OnLoadFinished of the Loader. It's an awful hack but it works.

Apparently I was not the only one with this problem (see this post for instance) but I've solved it in a another way.