Rails - Aug 2005 - Eager loading over multiple relationships?

Is it possible to perform eager loading over multiple relationships?   
Here''s a brief look at the relevant data models:

Project has_many Album has_many Song belongs_to Label

I feel all happy for properly modeled 3NF data but because of the way  
this is set up I have this method in Album to collect the Labels from  
its songs:

def labels
   songs.inject(Set.new) { |l, song| l << song.label }
end

and a similar one in Project.  Unfortunately all this requires  
loading a bunch of data just to get to my information and is hella  
slow.  Is there a way to specify eager loading of associations''  
associations?  Something like:

Project.find(:all, :include => :albums.songs.labels)

Or should I just make Project#labels and Album#labels find_by_sql  
methods and be done with it?

Thanks,
George
-- 
George Hotelling                  GPG: 0x8175D485 ]
http://george.hotelling.net                       ]
     _         _    _      ___      _         _   _/





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> and a similar one in Project.  Unfortunately all this requires loading a
> bunch of data just to get to my information and is hella slow.  Is there a
> way to specify eager loading of associations'' associations? 
Something like:
> 
> Project.find(:all, :include => :albums.songs.labels)
Nope.
> Or should I just make Project#labels and Album#labels find_by_sql methods
> and be done with it?
Yup.

If this is a big deal and you can figure out way to get multi-level
associations working without disturbing currently existing code, by
all means submit it as a patch.


-- 
rick
http://techno-weenie.net