Forum: Ruby on Rails Noob ? - Foreign Key

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Lewis Skolnick (Guest)
on 2008-12-10 10:56
(Received via mailing list)
I am attempting to use scaffolding to create a simple foreign key
example.  But I am not quite understanding how rails writes data into
the foreign table.  When the "belongs_to" and "has_many" lines are
added into model, will rails automatically add the information into
the foreign table?  Or do I have to modify the controller to insert
the data into the foreign table?  Could someone give me an example.  I
would like the data in the foreign table not to repeat itself.

The sample tables I am attempting to work with are Parts and
Revisions.  Where each revision has_many parts and each part
belongs_to revision.

Thanks for any Help!!!

Thorsten M. (Guest)
on 2008-12-10 11:36
(Received via mailing list)
ok, so if parts belongs_to Revision, it must have a revision_id
which you must have created in the migration.

Assuming you have a form that sends the Parts data (in params[:parts]
you know to which revision it should be added, then

@revision = Revision.find(revision_id) # however you get revision id,
could eg be params[:revision_id][:parts])

would be all you need.
First line getting the revision, next line adding the part to that
revision_id is set by Rails
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