Rails - Sep 2006 - Eager loading with acts_as_tree

So I have a model that acts_as_tree and I run a method on a collection
of all of these records. This method walks the tree and fetches the
parent/children, etc. This results in many, many duplicate SQL queries
to be executed. Is there a way to eagerly load all of these models?

Something along the lines of:
Model.find(:all, :include => [:children, :parent])

If I execute the above statement, I get an exception:
Mysql::Error: Column: ''parent_id'' in where clause is ambiguous

-Szymon


--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk
-~----------~----~----~----~------~----~------~--~---

Szymon Rozga wrote:
> So I have a model that acts_as_tree and I run a method on a collection
> of all of these records. This method walks the tree and fetches the
> parent/children, etc. This results in many, many duplicate SQL queries
> to be executed. Is there a way to eagerly load all of these models?
>
> Something along the lines of:
> Model.find(:all, :include => [:children, :parent])
>
> If I execute the above statement, I get an exception:
> Mysql::Error: Column: ''parent_id'' in where clause is
ambiguous
>
> -Szymon
Well I have found out that when I just load the root nodes/parents, it
automagically gets the children for me, but of course inside the
ActiveRecord-results. If I dont pass a condition, eg.. "@things
Things.find(:all)", I will get all the children in @things and under
"thing.children". If I pass a condition like "parent_id = 0"
then
@things just contains the root nodes, but the children are still
accessible.

Not sure if this was helpful, or if it even lessens the amount of SQL
Queries, but It produces more logical code.


--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Ruby on Rails: Talk" group.
To post to this group, send email to
rubyonrails-talk-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
To unsubscribe from this group, send email to
rubyonrails-talk-unsubscribe-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
For more options, visit this group at
http://groups.google.com/group/rubyonrails-talk
-~----------~----~----~----~------~----~------~--~---