Hello again!
Ok, I''m thinking that ''find'' has a condition I can
throw in here but I''m
just not familiar with using associations in find conditions (I could
just use raw SQL but that kills the beauty of this whole thing). Also,
I''d like to move less data across the wire and this approach requires
all data to be present...
So, that said.
Imagine a scenario where you have a Director that may or not have yet
directed a Movie. I''m wanting to return Directors to the view that
have
AT least one movie. Here''s my hack:
@directors = Director.find(:all).delete_if {|director|
director.movies.count == 0
}
I''m certain there''s a better way.
--
Posted via http://www.ruby-forum.com/.
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en
-~----------~----~----~----~------~----~------~--~---
On Jan 28, 2007, at 9:32 PM, Cory Wilkerson wrote:> Ok, I''m thinking that ''find'' has a condition I can throw in here > but I''m > just not familiar with using associations in find conditions (I could > just use raw SQL but that kills the beauty of this whole thing). > Also, > I''d like to move less data across the wire and this approach requires > all data to be present...it sounds like you want to do a select, e.g. @directors = Director.find(:all).select {|director| !(0 == director.movies.count)} -faisal --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
> @directors = Director.find(:all).select {|director| !(0 == > director.movies.count)}This method is still going to pull all of the directors from the database before filtering. I''d favour a more SQL heavy approach: Director.find(:all, :joins => ''inner join movies on movies.director_id = directors.id'', :group => ''directors.id'') SQL would naturally filter out the directors with no movies as the inner join requires the director to exist in the movies table. You then group the results so you just get the directors and not the associated movies. This is obviously more verbose than a straight find(:all) but you can just add a method to your model. If you find yourself using this across a few of your models, you can try and create a method you can use to extend active record. Hope that helps, Steve --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---