Thanks Phlip -
Thanks for the response - I'll play around with your suggestions.
What I was trying to do was something like this project.appointments to display
all the appointments for a specific project.
The way I have it set up is that a project has many tasks, each task can have
many resources (people) and each resource then has appointments. I'm not sure
this is the best way to model but I thought it would be easier just keeping one
reference to the project_id in the tasks table rather then trying to manage all
the links back up to the projects table from the resources and appointments
tables. Maybe a bad design decision??
----- Original Message ----
From: Phlip <[EMAIL PROTECTED]>
To: rubyonrails-talk@googlegroups.com
Sent: Saturday, September 6, 2008 8:52:49 PM
Subject: [Rails] Re: Active record question
Mark Studebaker wrote:
> I'm not quite sure how to get at this data using Actrive record.. I'm
> trying to get all the appointments made for a particular project. I'm
> using four models, Projects, Tasks, Resources and Appointments.
>
> The SQL gets me what I'm looking for but how do I do it using Active Record?
>
> Select a.* from appointments a
> join resources r on r.id = a.resource_id
> join tasks t on t.id = r.task_id
> join projects p on p.id = t.project_id
> Where project_id = 1;
Why is project joined in, if project_id comes from tasks?
And why is resources joined in? for its data? It does not participate in the
links, right?
> I can get all the Resources for a project using this but can not get the
> appointments. I could loop through the resources getting all the
> appointmen ts and tracking them, but that doesn't seem like the right
> way to do it. I could also use find_by_sql, but again, that does't seem
> right.
>
> class Project < ActiveRecord::Base
> has_many :tasks
> belongs_to :customer
> has_many :resources, :through => :tasks
Appointment.find( :all, :include => :tasks,
:conditions => { :'tasks.project_id' => 1} )
In summary, provide enough :has_many => :through to get to the keying table,
then put it into your :include and :conditions.
Warning: :include will eager-load, which might slow you down with irrelevant
data.
Alternately...
Task.find_all_by_project_id(1).map(&:appointments).uniq
(-:
--
Phlip
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