Rails - Oct 2005 - Foreign Key Question

I''m sorry for such a newbie question, but I am having a very hard  
time understanding how to input a foreign key into a new table record.

My app has riders and rides.
The rides model says: has_one :rider
The riders model says: has_many :rides

The rides DB table has 3 columns: id, user_id, miles

 From the riders "show" page, I have a link that sends them to the  
form to create a new ride: <%= link_to ''Create new ride'',
:controller
=> ''ride'' , :action => ''new'', :id
=> @rider %>

The "new" method in the ride controller then finds the corresponding  
user and loads them into memory:
def new
     @user = User.find(params[:id])
     @ride = Ride.new
   end

And the "new.rhtml" page for ride has a submit tag that sends the  
user to the "create" method of the ride controller: <%= submit_tag
"Create", :user_id => @user %>

But from here I am entirely lost. How do I get the user_id to go into  
the ride table entry as a foreign key? It doesn''t do it now, after  
having setup the relationship.

I am sure this is something simple, that I haven''t seen demonstrated  
elsewhere yet. Any help is incredibly appreciated.

Thanks!
--
Nathan Mealey
Webmaster & Administrative Coordinator
Cycle-Smart, Inc.
P.O. Box 1482
Northampton, MA
01061-1482
nathan-mPKOtHdLgT0QaXB9iyTzyw@public.gmane.org

Nathan,

you''re not using "has_one" and "has_many" in the
way they''re intended.
A "has_one" is typically paired with a "belongs_to", where
the table
of the class specifying "belongs_to" contains the secondary key.

So in your case, you might write

class Rider < ActiveRecord::Base
  has_one :ride
end
class Ride < ActiveRecord::Base
  belongs_to :rider
end

With this setup, your db table "rides" would contain a field
"rider_id" (not "user_id"), which is your secondary key.

While the above will work, I don'' think it is what you really want --
unless you want to allow only a single rider for each ride... I prefer
riding in groups :) You should look up the "has_and_belongs_to_many"
association at http://ar.rubyonrails.com.  (I''m assuming you mean ride
as in "trip", not ride as in "bike")

If you don''t have too many Rider instances, you could display a
checkbox for each existing Rider in your rides/new.rhtml, and
associate the selected Riders with the new Ride in your
RidesController#create method.
> <%= submit_tag "Create", :user_id => @user %>
This is not how submit_tag works. see
http://ap.rubyonrails.org/classes/ActionView/Helpers/FormTagHelper.html

cheers
Gerret
>
> But from here I am entirely lost. How do I get the user_id to go into
> the ride table entry as a foreign key? It doesn''t do it now, after
> having setup the relationship.
>
> I am sure this is something simple, that I haven''t seen
demonstrated
> elsewhere yet. Any help is incredibly appreciated.
>
> Thanks!
> --
> Nathan Mealey
> Webmaster & Administrative Coordinator
> Cycle-Smart, Inc.
> P.O. Box 1482
> Northampton, MA
> 01061-1482
> nathan-mPKOtHdLgT0QaXB9iyTzyw@public.gmane.org
>
>
>
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>