Querying an unrelated table

Rails
1

I have three tables: Case, Attorney and Firm. Case belongs to Attorney
and Attorney Belongs to Firm. I don’t see how I can define that Case
belongs to Firm through Attorney since Attorney is not a join table
(does not reference both). In order to find all cases for a Firm, it
seems I must write a sequence of queries like this:

class FirmsController < ApplicationController

def show
id = params[:id]
@attorneys = Attorney.find(:all, :conditions => [“firm_id = ?”, id])
@cases = Case.find(:all, :conditions => [“attorney_id = ?”,
@attorneys.id])
end

end

In this sequence however, @cases doesn’t return any case objects. How
might I get this to work?

Thanks,

Peter

2

Peter M. wrote:

def show
id = params[:id]
@attorneys = Attorney.find(:all, :conditions => [“firm_id = ?”, id])
@cases = Case.find(:all, :conditions => [“attorney_id = ?”,
@attorneys.id])
end

@cases = Case.find(:all,
:include => [ { :attorney => :firm } ],
:conditions => [ “firm.id = ?”, params[:id]])

Clifford H…

3

Clifford H. wrote:

Peter M. wrote:

def show
id = params[:id]
@attorneys = Attorney.find(:all, :conditions => [“firm_id = ?”, id])
@cases = Case.find(:all, :conditions => [“attorney_id = ?”,
@attorneys.id])
end

@cases = Case.find(:all,
:include => [ { :attorney => :firm } ],
:conditions => [ “firm.id = ?”, params[:id]])

Clifford H…

Excellent. Thanks Clifford. :slight_smile:

4

Peter M. wrote:

I have three tables: Case, Attorney and Firm. Case belongs to Attorney
and Attorney Belongs to Firm. I don’t see how I can define that Case
belongs to Firm through Attorney since Attorney is not a join table
(does not reference both). In order to find all cases for a Firm, it
seems I must write a sequence of queries like this:

class FirmsController < ApplicationController

def show
id = params[:id]
@attorneys = Attorney.find(:all, :conditions => [“firm_id = ?”, id])
@cases = Case.find(:all, :conditions => [“attorney_id = ?”,
@attorneys.id])
end

end

In this sequence however, @cases doesn’t return any case objects. How
might I get this to work?

As others have pointed out, you can use :include to find things. You
might also want to use an asymetric join model.

Attorney
has_many :cases

Firm
has_many :attorneys
has_many :cases, :through => :attorneys

@firm = Firm.find(params[:id])
@cases = @firm.cases

That will work when the join model is like yours, a belongs_to and a
has_many.

–
Josh S.
http://blog.hasmanythrough.com

5

Peter M. wrote:
…

@cases = Case.find(:all, :conditions => ["attorney_id = ?",

@attorneys.id])
Excellent. Thanks Clifford. :slight_smile:

BTW, @attorneys.id isn’t what you think, in your original code.
You got the Ruby object_id, not the id attribute from ActiveRecord.
This is a major trap, because it sometimes does what you want.

Just ALWAYS write @thing[:id] instead… or build your schemas with
config.active_record.primary_key_prefix_type = :table_name
and suffer the fact that the generators might not all do the right
thing.

Clifford H.