Rails - Oct 2005 - false id using ActiveRecord find :all :joins

Hi,
maybe this is a well known issue, btw it wasn''t to me :-)
I''ve quickly checked the mailing list without .

I''ve got thoose two models
Riba and Fatture

class Riba < ActiveRecord::Base
  set_table_name :riba
  belongs_to :fatture

class Fatture < ActiveRecord::Base
  set_table_name :fatture
  belongs_to :client
  belongs_to :tipo_pagamento
  has_many :bolle
  has_many :righe_fatture
  has_many :riba

within Riba I''ve got a method looking for a riba list

    #list_riba = self.find(:all,
    #                       :conditions => ["extract(month from
datafattura) = ? AND extract(year from datafattura) = ?", mese_scelto,
anno],
    #                       :joins => "INNER JOIN fatture ON
fatture.id = riba.fatture_id",
    #                       :order => "fatture.numero")

    list_riba = self.find_by_sql(["SELECT r.id, fatture_id, importo,
stampata FROM riba r INNER JOIN fatture ON fatture.id = r.fatture_id
WHERE extract(month from datafattura) = ? AND extract(year from
datafattura) = ? ORDER BY fatture.numero", mese_scelto, anno])

using the commented way, when I refer to list_riba[i].id I get the
value of list_riba.fatture.id
Using the second way list_riba[i].id actually refer to the correct Riba.id value

Is something about the way I''ve done it? Or is it just a lack of the
find method?

Enrico

--
"The only thing necessary for the triumph of evil
is for good men to do nothing"
 Edmund Burke

Enrico Teotti <agenteo@...> writes:
> Hi,
> maybe this is a well known issue, btw it wasn''t to me 
> I''ve quickly checked the mailing list without .
> Is something about the way I''ve done it? Or is it just a lack of
the
> find method?
I''ve been bitten by this too and found the solution;

  http://dev.rubyonrails.com/ticket/1338

I don''t think it has been implemented in 0.13.1 yet but you can put
something
like:

  class ActiveRecord::Base
    def self.construct_finder_sql(options)
      joins = options[:joins]
      order = options[:order]
      select = options[:select] || ''*''
      sql = "SELECT #{select} FROM #{table_name} "  
      sql << "#{joins} " if joins
      add_conditions!(sql, options[:conditions]) 
      sql << "ORDER BY #{order} " if order
      add_limit!(sql, options)          
      sql
    end
  end

in your enviroment.rb file as a temporary workaround.  With this in place you
can include :select => ''riba.*'' in your find statement to
select the proper
fields;

  list_riba = self.find(:all,
     :select => ''riba.*'',
     :conditions => ["extract(month from datafattura) = ?
         AND extract(year from datafattura) = ?", mese_scelto, anno],
     :joins => "INNER JOIN fatture ON fatture.id =
riba.fatture_id",
     :order => "fatture.numero")

HTH,
Remco

Remco van t Veer <rwvtveer@...> writes:
>   class ActiveRecord::Base
>     def self.construct_finder_sql(options)
Should be:

  class << ActiveRecord::Base
    def construct_finder_sql(options)

Cheers,
Remco

Remco van t Veer wrote:
> Remco van t Veer <rwvtveer@...> writes:
> 
>>  class ActiveRecord::Base
>>    def self.construct_finder_sql(options)
> 
> 
> Should be:
> 
>   class << ActiveRecord::Base
>     def construct_finder_sql(options)
Remco, would you be able to explain the difference
between these.  And also in what cases do you instead
have to use module_eval/class_eval to modify AR
methods via user libraries and environment.rb.

-- 
We develop, watch us RoR, in numbers too big to ignore.

Mark Reginald James <mrj@...> writes:
> >>  class ActiveRecord::Base
> >>    def self.construct_finder_sql(options)
> > 
> > Should be:
> > 
> >   class << ActiveRecord::Base
> >     def construct_finder_sql(options)
> 
> Remco, would you be able to explain the difference
> between these.  And also in what cases do you instead
> have to use module_eval/class_eval to modify AR
> methods via user libraries and environment.rb.
The first snippet is just wrong.  It redefines AR::Base and leaves you with a
AR::Base with nothing but the given method.  I was too busy when I was writing
that post and only noticed it when I was checking for a reply.

The new snippet changes the definition of the AR::Base class _object_.  It is
only possible to alter class methods in this way.  Since I only need to change
a class method here the "class <<" method is fine.  The
class_eval method is
much more powerful, it also allows you the change object methods and other
stuff.

HTH,
Remco

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On Oct 4, 2005, at 11:44 PM, Remco van t Veer wrote:
> Mark Reginald James <mrj@...> writes:
>>>>  class ActiveRecord::Base
>>>>    def self.construct_finder_sql(options)
>>>
>>> Should be:
>>>
>>>   class << ActiveRecord::Base
>>>     def construct_finder_sql(options)
>>>
>>
>> Remco, would you be able to explain the difference
>> between these.  And also in what cases do you instead
>> have to use module_eval/class_eval to modify AR
>> methods via user libraries and environment.rb.
>>
>
> The first snippet is just wrong.  It redefines AR::Base and leaves  
> you with a
> AR::Base with nothing but the given method.  I was too busy when I  
> was writing
> that post and only noticed it when I was checking for a reply.
Ruby classes are open.  The first way is fine.  Fire up irb and play  
around with it.

Best,
jeremy
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Jeremy Kemper <jeremy@...> writes:
 
> On Oct 4, 2005, at 11:44 PM, Remco van t Veer wrote:
> > Mark Reginald James <mrj <at> ...> writes:
> >>>>  class ActiveRecord::Base
> >>>>    def self.construct_finder_sql(options)
> >>>
> >>> Should be:
> >>>
> >>>   class << ActiveRecord::Base
> >>>     def construct_finder_sql(options)
> >
> > The first snippet is just wrong.  It redefines AR::Base and leaves  
> > you with a
> > AR::Base with nothing but the given method.  I was too busy when I  
> > was writing
> > that post and only noticed it when I was checking for a reply.
> 
> Ruby classes are open.  The first way is fine.  Fire up irb and play  
> around with it.
Wow..  The java programmer in me is very angry now!  ;)

Apparently there''s a lot of ways to change a class definition.  After
reading;

  http://www.rubygarden.org/ruby?ClassMethodsTutorial

I will change my enviroment.rb to:

  def ActiveRecord::Base.construct_finder_sql(options)
  ..
  end

Thanks Jeremy for your hint.  I need to do my meta programming katas.

Remco

thanks to everone

--
"The only thing necessary for the triumph of evil
is for good men to do nothing"
 Edmund Burke