belongs_to do unique key

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2 total messages Started by FOX Tue, 26 Aug 2008 21:58

#1112

Author: FOX
Date: Tue, 26 Aug 2008 21:58

48 lines
950 bytes

Witam

Mam taki problem z niestandardow� konwencj� powi�za� tabal.
Jak mo�na zdefiniowa� inne ni� domy�lne
zachowanie belongs_to do klucza unikalnego a nie g�ownego.

Oto konkretny przypadek 2 tabel

tabela 1 (waluty):

currencies (
   id        int      - PK
   currency  char(3)  - UK
   name      text
   format    text
)


tabele 2 (kursy):

exchanges (
   id        int      - PK
   currency  char(3)  - FK do currencies(currency)
   date      date
   course    number(10,4)
)



class Currency < ActiveRecord::Base
   has_many :exchange
end

class Exchange < ActiveRecord::Base
   belongs_to :currency,  :foreign_key => ...........
       :conditions => '"exchanges".currency = "currencies".curency'
end


i tutaj w miejsce kropek przyda�oby si� jakie�
wy��czenie domy�lnego zachowania foreign_key

lub mo�e jest jaka� magiczna funkcja kt�r� nale�a�oby nadpisa� dla klasy
Exchange.

Pozdrawiam
FOX

Re: belongs_to do unique key

#1172

Author: Zbyszek Malec
Date: Tue, 17 Feb 2009 19:25

32 lines
794 bytes

Dnia Tue, 26 Aug 2008 21:58:38 +0200, FOX napisa�(a):

> class Currency < ActiveRecord::Base
>    has_many :exchange
> end
>
> class Exchange < ActiveRecord::Base
>    belongs_to :currency,  :foreign_key => ...........
>        :conditions => '"exchanges".currency = "currencies".curency'
> end
>
>
> i tutaj w miejsce kropek przyda�oby si� jakie�
> wy��czenie domy�lnego zachowania foreign_key

Nie mam jakiego� wi�kszego do�wiadczenia z ActiveRecord, wi�c jak bym
g�upoty pisa�, to licz� �e mnie kto� poprawi.

class Currency < ActiveRecord::Base
	has_many :exchange, :primary_key => 'currency', :foreign_key => 'currency'
end

class Exchange < ActiveRecord::Base
	belongs_to :currency, :foreign_key => 'currency'
end

I jak?

--
Zbyszek Malec
gg 2756100

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