Rails - Mar 2010 - getting data from a through table

im using has_many through and the through table has some data i want
but i cant seem to access it using straight rails

<code>
class AttributeObjects < ActiveRecord::Base
  belongs_to :attributes
  belongs_to :objects
end

class Attributes < ActiveRecord::Base
  has_many :attribute_objects
  has_many :objects, :through => :attribute_objects
end

class Objects < ActiveRecord::Base
  has_many :attribute_objects
  has_many :attributes, :through => :attribute_objects
end

</code>

now imagine that attribute_objects also contains a rating
so when i say, object.attributes, id like to get the rating too
that doesnt seem to be possible with the has_many relationship
if i could force the join on the object attributes to bring the
attribute_objects fields also...maybe

i think i have to write custom sql for this

-- 
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-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en.

On 19 March 2010 03:49, dan
<mr.dan.marks-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
wrote:
> now imagine that attribute_objects also contains a rating
> so when i say, object.attributes, id like to get the rating too
> that doesnt seem to be possible with the has_many relationship
> if i could force the join on the object attributes to bring the
> attribute_objects fields also...maybe
If you want to access properties of AttributeObjects [1], you can
iterate the collection of them, not the collection of attributes.
So instead of:

@object.attributes.each do |attribute|
  attribute.name ....
end

you do this:
@object.attribute_objects.each do |attribute_object|
  attribute_object.attribute.name ....
  attribute_object.rating ....
end
> i think i have to write custom sql for this
You can if you want... but you don''t *have* to.
You can possibly use the ":finder_sql" option of the association to
specify your own conditions for populating the collection (I''ve been
fiddling with it here for 10mins, and not got it working... post up
some working code if it does it for you :-)
http://api.rubyonrails.org/classes/ActiveRecord/Associations/ClassMethods.html


[1] All your class names are plural; they should really be singular...

-- 
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-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en.

thanks for the suggestions

attributes is a self inherited table
so i need to get them i order of top level and down
this is part of my current solution

has_many :objects_attributes do
    def top_level
      all(:joins => :attribute, :conditions => "attributes.parent_id
is null")
    end

    def children(id)
      all(:joins => :attribute, :conditions => ["attributes.parent_id
= ?", id])
    end
end

this allows me to access all fields in order desired
thanks for your help

-- 
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-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk?hl=en.