Rails - Feb 2006 - How to build a recursive parenting structure?

I''m just getting used to using HABTM structures.  Something
I''m trying
to do now is create a site that has "sections" each section then could
have a sub "section".

So I built a "sections" table and in the model I included the line 
"has_and_belongs_to_many :sections"
I also made a table called "sections_sections" to build the heirarchy 
however the fields I generated were:

CREATE TABLE  `sections_sections` (
 `section_id` INT( 10 ) UNSIGNED NOT NULL,
 `parent_id` INT( 10 ) UNSIGNED NOT NULL ,
 constraint fk_parents foreign key (parent_id) references sections(id),
 constraint fk_sections foreign key (section_id) references sections(id)
);

Because I can''t have two section_id fields.  So how can I let rails
know
that it should look for parent_id when I do something like: 
@section.sections.include?(@section_to_look_for)?


-- 
Posted via http://www.ruby-forum.com/.

Sounds like what you''re looking for is :acts_as_tree
Unless a section can have more than one parent, there is
no need for a HABTM table, just put the parent_id column
in the sections table, and add :acts_as_tree.

joshua

On 2/26/06, Todd S. <tgate@mypublic.net> wrote:
>
> I''m just getting used to using HABTM structures.  Something
I''m trying
> to do now is create a site that has "sections" each section then
could
> have a sub "section".
>
> So I built a "sections" table and in the model I included the
line
> "has_and_belongs_to_many :sections"
> I also made a table called "sections_sections" to build the
heirarchy
> however the fields I generated were:
>
> CREATE TABLE  `sections_sections` (
> `section_id` INT( 10 ) UNSIGNED NOT NULL,
> `parent_id` INT( 10 ) UNSIGNED NOT NULL ,
> constraint fk_parents foreign key (parent_id) references sections(id),
> constraint fk_sections foreign key (section_id) references sections(id)
> );
>
> Because I can''t have two section_id fields.  So how can I let
rails know
> that it should look for parent_id when I do something like:
> @section.sections.include?(@section_to_look_for)?
>
>
> --
> Posted via http://www.ruby-forum.com/.
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
>
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