Rails - Nov 2006 - Still Having Problems With :through When Going To Same Table... Help... please :-(

I am having a problem with doing a :through that goes back to the same table.

The following are my two classes:
>>>>>
class User < ActiveRecord::Base
  has_many :spanks
  has_many :spanked, :through => :spanks, :source => :spanked_user
  has_many :was_spanked_by, :through => :spanks, :source => :user
end

class Spank < ActiveRecord::Base
  belongs_to :spanker, :class_name => "User", :foreign_key =>
"user_id"
  belongs_to :spankee, :class_name => "User", :foreign_key =>
"spanked_user_id"
end

db_table:spanks
id | user_id | spanked_user_id | created_at | updated_at
>>>>>
I want to be able to make statemets like:

john = User.find_by_nickname("john")
john.spanked
john.was_spanked_by

Can I do this without using a :finder_sql?

The above does not work... but the following does:

john.spanks
spank = Spank.find(1)
spank.spankee
spank.spanker

Help... help... I get the following error:

ActiveRecord::HasManyThroughSourceAssociationNotFoundError:ActiveRecord::HasManyThroughSourceAssociationNotFoundError



-- 
John Kopanas
john-Iau1QiYlxLpBDgjK7y7TUQ@public.gmane.org

http://www.kopanas.com
http://www.cusec.net
http://www.soen.info

--~--~---------~--~----~------------~-------~--~----~
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
-~----------~----~----~----~------~----~------~--~---

John Kopanas wrote:
> I am having a problem with doing a :through that goes back to the same
table.
>   
Try this...

class User < ActiveRecord::Base
  has_many :spanks_as_spankee,
:foreign_key=>''spanked_user_id'', :class_name =>
''Spank''
  has_many :spanks_as_spanker, :foreign_key=>''user_id'',
:class_name => ''Spank''
  has_many :spanked, :through => :spanks_as_spankee
  has_many :was_spanked_by, :through => :spanks_as_spanker
end

although, if it were my app, I would make some small association and
column name changes as well, so that...
 

class User < ActiveRecord::Base
  has_many :spanks_as_spankee, :foreign_key=>''spankee_id'',
:class_name => ''Spank''
  has_many :spanks_as_spanker, :foreign_key=>''spanker_id'',
:class_name => ''Spank''
  has_many :spankees, :through => :spanks_as_spankee
  has_many :spankers, :through => :spanks_as_spanker
end

class Spank < ActiveRecord::Base
  belongs_to :spanker, :class_name => "User", :foreign_key =>
"spanker_id"
  belongs_to :spankee, :class_name => "User", :foreign_key =>
"spankee_id"
end


Note: I haven''t actually tested the above, but I''ve done
similar and it
works great. Credit goes to Josh Susser for showing me how to do self
referential :throughs a while back via his blog.
http://blog.hasmanythrough.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
-~----------~----~----~----~------~----~------~--~---

Jon Garvin wrote:
> John Kopanas wrote:
>   
>> I am having a problem with doing a :through that goes back to the same
table.
>>   
>>     
> Try this...
>
> class User < ActiveRecord::Base
>   has_many :spanks_as_spankee,
:foreign_key=>''spanked_user_id'', :class_name =>
''Spank''
>   has_many :spanks_as_spanker,
:foreign_key=>''user_id'', :class_name =>
''Spank''
>   has_many :spanked, :through => :spanks_as_spankee
>   has_many :was_spanked_by, :through => :spanks_as_spanker
> end
>
> although, if it were my app, I would make some small association and
> column name changes as well, so that...
>  
>
> class User < ActiveRecord::Base
>   has_many :spanks_as_spankee,
:foreign_key=>''spankee_id'', :class_name =>
''Spank''
>   has_many :spanks_as_spanker,
:foreign_key=>''spanker_id'', :class_name =>
''Spank''
>   has_many :spankees, :through => :spanks_as_spankee
>   has_many :spankers, :through => :spanks_as_spanker
> end
>
> class Spank < ActiveRecord::Base
>   belongs_to :spanker, :class_name => "User", :foreign_key
=> "spanker_id"
>   belongs_to :spankee, :class_name => "User", :foreign_key
=> "spankee_id"
> end
>
>
> Note: I haven''t actually tested the above, but I''ve done
similar and it
> works great. Credit goes to Josh Susser for showing me how to do self
> referential :throughs a while back via his blog.
> http://blog.hasmanythrough.com/
>
>   
Whoops, got an association backwards in the alternate option above. This
is what I meant...

class User < ActiveRecord::Base
  has_many :spanks_as_spankee, :foreign_key=>''spankee_id'',
:class_name => ''Spank''
  has_many :spanks_as_spanker, :foreign_key=>''spanker_id'',
:class_name => ''Spank''
  has_many :spank*ers*, :through => :spanks_as_spankee
  has_many :spank*ees*, :through => :spanks_as_spanker
end




--~--~---------~--~----~------------~-------~--~----~
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
-~----------~----~----~----~------~----~------~--~---

Worked great!  Thanks Jon... but now I have a couple questions for you
if you don''t mind :-).

1) why is :through point to a has_many relatioship?  I thought it
usually points to an object/table.

2) If I change spankers to spanked_by it breaks... why?

Thanks again for your help :-).


On 11/2/06, Jon Garvin
<jgarvin.lists-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
wrote:
>
>  Jon Garvin wrote:
>  John Kopanas wrote:
>
>
>  I am having a problem with doing a :through that goes back to the same
> table.
>
>
>  Try this...
>
> class User < ActiveRecord::Base
>  has_many :spanks_as_spankee,
> :foreign_key=>''spanked_user_id'', :class_name =>
''Spank''
>  has_many :spanks_as_spanker, :foreign_key=>''user_id'',
:class_name =>
> ''Spank''
>  has_many :spanked, :through => :spanks_as_spankee
>  has_many :was_spanked_by, :through => :spanks_as_spanker
> end
>
> although, if it were my app, I would make some small association and
> column name changes as well, so that...
>
>
> class User < ActiveRecord::Base
>  has_many :spanks_as_spankee,
:foreign_key=>''spankee_id'', :class_name =>
> ''Spank''
>  has_many :spanks_as_spanker,
:foreign_key=>''spanker_id'', :class_name =>
> ''Spank''
>  has_many :spankees, :through => :spanks_as_spankee
>  has_many :spankers, :through => :spanks_as_spanker
> end
>
> class Spank < ActiveRecord::Base
>  belongs_to :spanker, :class_name => "User", :foreign_key
=> "spanker_id"
>  belongs_to :spankee, :class_name => "User", :foreign_key
=> "spankee_id"
> end
>
>
> Note: I haven''t actually tested the above, but I''ve done
similar and it
> works great. Credit goes to Josh Susser for showing me how to do self
> referential :throughs a while back via his blog.
> http://blog.hasmanythrough.com/
>
>
>  Whoops, got an association backwards in the alternate option above. This
is
> what I meant...
>
>  class User < ActiveRecord::Base
>  has_many :spanks_as_spankee,
:foreign_key=>''spankee_id'', :class_name =>
> ''Spank''
>  has_many :spanks_as_spanker,
:foreign_key=>''spanker_id'', :class_name =>
> ''Spank''
>  has_many :spankers, :through => :spanks_as_spankee
>  has_many :spankees, :through => :spanks_as_spanker
> end
>
>
>  >
>

-- 
John Kopanas
john-Iau1QiYlxLpBDgjK7y7TUQ@public.gmane.org

http://www.kopanas.com
http://www.cusec.net
http://www.soen.info

--~--~---------~--~----~------------~-------~--~----~
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
-~----------~----~----~----~------~----~------~--~---

John Kopanas wrote:
> Worked great!  Thanks Jon... but now I have a couple questions for you
> if you don''t mind :-).
>
> 1) why is :through point to a has_many relatioship?  I thought it
> usually points to an object/table.
>
> 2) If I change spankers to spanked_by it breaks... why?
>
> Thanks again for your help :-).
>
>
>   
Josh Susser, or anyone else more familiar with how this technique works,
can probably provide much better answers.  But...

1) Yes, normally it would point directly to the join model/table. 
However, to do more complex stuff (like self referential has_many
:throughs), sometimes you gotta break out the magic wand and wave it
with enthusiasm.

2) I just guessing, but maybe the ''_by'' suffix is getting some
other
Rails magic applied to it.  Try changing it to :spanked_bx, and see if
that helps. Either way, someone more familiar than I with the Rails
internals might be able to explain it.

--~--~---------~--~----~------------~-------~--~----~
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
-~----------~----~----~----~------~----~------~--~---