Forum: Ruby on Rails How to build a recursive parenting structure?

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Todd S. (Guest)
on 2006-02-27 05:56
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:
Joshua B. (Guest)
on 2006-02-27 23:40
(Received via mailing list)
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.

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