Select or SelectList: I Want to include the entire entity - nhibernate

Question

I am querying a list of objects, and then correlating them with a subquery.
I want to return the results of the subquery, as well as the root entity. But
I can't figure out how to actually return the root entity, I can only return individual properties of it.
Specifically, this works:
this.Session.QueryOver<MediaFile>(() => mediaFile)
.SelectList(list => list.Select(mf => mf.Id));
But this does not:
this.Session.QueryOver<MediaFile>(() => mediaFile)
.SelectList(list => list.Select(mf => mf));
I get the following error:
Could not resolve property : of MediaFile
Does anyone know how I can include the entity as a property in the list?
Here's my complete example:
// My target class
private class MediaFileAndCount
{
// I can successfully populate these fields.
public long MediaFileId { get; set; }
public int DistinctPlaylistCount { get;set; }
// But I want to populate this field!
public MediaFile MediaFile { get; set; }
}
private void TrySingleQuery()
{
MediaFile mediaFile = null;
PlaylistEntry playlistEntry = null;
MediaFileAndCount mfc = null;
var subQuery = QueryOver.Of<PlaylistEntry>(() => playlistEntry)
.Where(() => playlistEntry.MediaFile.Id == mediaFile.Id)
.Select(Projections.CountDistinct<PlaylistEntry>(p => p.Playlist));
var query = this.Session.QueryOver<MediaFile>(() => mediaFile)
.SelectList(list => list
.Select(mf => mf.Id).WithAlias(() => mfc.MediaFileId)
.Select(Projections.SubQuery(subQuery)).WithAlias(() => mfc.DistinctPlaylistCount)
// .Select(mf => mf).WithAlias(() => mfc.MediaFile) // This line fails
)
.TransformUsing(Transformers.AliasToBean<MediaFileAndCount>());
var results = query.List<MediaFileAndCount>();
}

Answer 1

another way to query it
var allMediaFiles = session.QueryOver<MediaFile>().Where(...).ToFuture(); // just get the MediaFiles into sessionCache
var results = session.QueryOver<PlaylistEntry>()
.Where(p => p.MediaFile...)
.SelectList(list => list
.GroupBy(p => p.MediaFile.Id)
.CountDistinct(p => p.Playlist))
.ToFuture<object[]>()
.Select(a => new MediaFileAndCount
{
MediaFile = session.Get<MediaFile>((long)a[0]),
DistinctPlaylistCount = (int)a[1]
})
.ToList();
foreach (var mediaFile in allMediaFiles.Except(results.Select(r => r.MediaFile)))
{
results.Add(new MediaFileAndCount { MediaFile = mediaFile });
}