Rails - Apr 2006 - belongs_to :through

belongs_to :through

Why is that not possible?

We should have:

Street
belongs_to :city
belongs_to :country, :through => :city

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Wiktor  wrote:
> belongs_to :through
> 
> Why is that not possible?
> 
> We should have:
> 
> Street
> belongs_to :city
> belongs_to :country, :through => :city

Anyone?

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Wiktor  wrote:
> belongs_to :through
> 
> Why is that not possible?
> 
> We should have:
> 
> Street
> belongs_to :city
> belongs_to :country, :through => :city
I don''t see how that would get you much. You can simulate the
convenient
access to the country by delegating to the city, and if you are 
concerned about double queries, just use an :include on city to fetch 
the country at the same time.

Street
  belongs_to :city, :include => :country
  delegate :country, :country=, :to => :city

--
Josh Susser
http://blog.hasmanythrough.com

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Josh Susser wrote:
> Street
>   belongs_to :city, :include => :country
>   delegate :country, :country=, :to => :city

Josh,

It is awesome, thanks. That''s what I was looking for. Now, maybe you 
would be able to help me also with opposite problem:

class Country < ActiveRecord::Base

  has_many :states
  has_many :cities, :through => :states
  has_many :streets, :through => :cities

It doesn''t work...
I wan''t to use country.streets(...)

I was trying to use :finder_sql => ''SELECT streets.* FROM states, 
cities, streets WHERE states.country_id = #{id} AND cities.state_id = 
states.id AND streets.city_id = cities.id'' but I get an error:

Mysql::Error: #21000Operand should contain 1 column(s): SELECT * FROM 
streets WHERE (SELECT streets.* FROM states, cities, streets WHERE 
states.country_id = 1 AND cities.state_id = states.id AND 
streets.city_id = cities.id) AND (streets.`subdomain` = ''test''
)  LIMIT
1

When using:
@country.streets.find_by_subdomain(@sub.first)

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> class Country < ActiveRecord::Base
> 
>   has_many :states
>   has_many :cities, :through => :states
>   has_many :streets, :through => :cities
> 
> It doesn''t work...
Anyone?

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