Rails - May 2006 - Ordering Results returned by has_many relationship.

Noob Question 31,265,232

if I''m searching on an object, say order, that has many
"order_lines"
and I want to display order lines by Quantity ( an attribute of the 
order_lines ) descending
how could I do that without having to do a find() with :order, but 
something like;

Order.order_lines.each do |ol|
   <!-- code to diplay the line -->

how can I determine the field and the way I order the results?

Thanks in advance,
Randal the Newbie

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

On May 2, 2006, at 04:28 PM, Randal Santia wrote:
> Noob Question 31,265,232
>
> if I''m searching on an object, say order, that has many
"order_lines"
> and I want to display order lines by Quantity ( an attribute of the
> order_lines ) descending
> how could I do that without having to do a find() with :order, but
> something like;
>
> Order.order_lines.each do |ol|
>    <!-- code to diplay the line -->
>
> how can I determine the field and the way I order the results?
class Order < ActiveRecord::Base
   has_many :order_lines, :order => "order_lines.quantity"
end

More info: <http://rails.rubyonrails.org/classes/ActiveRecord/ 
Associations/ClassMethods.html#M000530>

-Brian

Since Order.order_lines is really just an array, then you can use the sort
feature of an array like this:

sorted = Order.order_lines.sort {|x,y| y.quantity <=> x.quantity }

Then do

sorted.each...

Hope this helps!

-----Original Message-----
From: rails-bounces@lists.rubyonrails.org
[mailto:rails-bounces@lists.rubyonrails.org]On Behalf Of Randal Santia
Sent: Tuesday, May 02, 2006 4:28 PM
To: rails@lists.rubyonrails.org
Subject: [Rails] Ordering Results returned by has_many relationship.


Noob Question 31,265,232

if I''m searching on an object, say order, that has many
"order_lines"
and I want to display order lines by Quantity ( an attribute of the 
order_lines ) descending
how could I do that without having to do a find() with :order, but 
something like;

Order.order_lines.each do |ol|
   <!-- code to diplay the line -->

how can I determine the field and the way I order the results?

Thanks in advance,
Randal the Newbie

-- 
Posted via http://www.ruby-forum.com/.
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Nevermind, I''m just a little slow.  I was puttin in the ORDER class,
how
to order the order_lines, and didn''t realise I could do

has_many  :order_lines, :order => "quantity DESC"

problem solved, and now archieved for future noobs :)

Randal Santia wrote:
> Noob Question 31,265,232
> 
> if I''m searching on an object, say order, that has many
"order_lines"
> and I want to display order lines by Quantity ( an attribute of the 
> order_lines ) descending
> how could I do that without having to do a find() with :order, but 
> something like;
> 
> Order.order_lines.each do |ol|
>    <!-- code to diplay the line -->
> 
> how can I determine the field and the way I order the results?
> 
> Thanks in advance,
> Randal the Newbie

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