CODEWITHSUNDEEP
ruby-on-railsrubyruby-on-rails-3
Vinra Gunanta Pandia
Vinra Gunanta Pandia

Reputation: 301

check Relationship table on model, ruby on rails

i have project with ruby on rails 3.2.14. i have 2 table named "countries" and "users". in "users" table have FK named "countries_id". on model i have make table relation like: in countries.rb i have set relationship like:

class Countries < ActiveRecord::Base
  self.primary_key = "id"
  has_many  :users,  :dependent => :destroy # plural
end

and in users.rb like:

class Users < ActiveRecord::Base
  self.primary_key = "id"


  belongs_to    :countries,
                :class_name => "Countries",
                :foreign_key => "countries_id"

end

and when i want to check plural relationship, it's didn't.. i type in rails console command like below

c=Countries.find_by_id(1)

and then when i type command u=c.users , i have some error the error:

c=Countries.find_by_id(1)
  Countries Load (0.3ms)  SELECT `countries`.* FROM `countries` WHERE `countries`.`id` = 1 LIMIT 1
 => #<Countries id: 1, code: "IND", name: "Indonesia", created_at: "2014-02-17 09:18:11", updated_at: "2014-02-17 09:18:11"> 
1.9.3-p484 :012 > u=c.users
NameError: uninitialized constant Countries::User
    from /home/vinra/.rvm/gems/[email protected]/gems/activerecord-3.2.14/lib/active_record/inheritance.rb:111:in `compute_type'
    from /home/vinra/.rvm/gems/[email protected]/gems/activerecord-3.2.14/lib/active_record/reflection.rb:172:in `klass'
    from /home/vinra/.rvm/gems/[email protected]/gems/activerecord-3.2.14/lib/active_record/associations/association.rb:118:in `klass'
    from /home/vinra/.rvm/gems/[email protected]/gems/activerecord-3.2.14/lib/active_record/associations/association.rb:171:in `find_target?'
    from /home/vinra/.rvm/gems/[email protected]/gems/activerecord-3.2.14/lib/active_record/associations/collection_association.rb:334:in `load_target'
    from /home/vinra/.rvm/gems/[email protected]/gems/activerecord-3.2.14/lib/active_record/associations/collection_proxy.rb:44:in `load_target'
    from /home/vinra/.rvm/gems/[email protected]/gems/activerecord-3.2.14/lib/active_record/associations/collection_proxy.rb:87:in `method_missing'
    from /home/vinra/.rvm/gems/[email protected]/gems/railties-3.2.14/lib/rails/commands/console.rb:47:in `start'
    from /home/vinra/.rvm/gems/[email protected]/gems/railties-3.2.14/lib/rails/commands/console.rb:8:in `start'
    from /home/vinra/.rvm/gems/[email protected]/gems/railties-3.2.14/lib/rails/commands.rb:41:in `<top (required)>'
    from script/rails:6:in `require'
    from script/rails:6:in `<main>'
1.9.3-p484 :013 > ^C
1.9.3-p484 :013 >

i really hopping somebody knowing my problem, anyway thank you,, sorry for my bad english :)

Upvotes: 1

Views: 2250

Answers (2)

Pavan
Pavan

Reputation: 33542

The Problem is that Rails Active Record Models cant be Plural. You created the models with plural,so change them to singular or better way is to create them again with singular names.

Countries should be Country and Users should be User.

For more information on Naming Conventions,see This.

Hope it helps!

Upvotes: 0

Maksim Gladkov
Maksim Gladkov

Reputation: 3079

You should change a lot of things in your code:

app/models/country.rb

class Country < ActiveRecord::Base
    has_many :users, :dependent => :destroy
end

app/models/user.rb

class Users < ActiveRecord::Base
    belongs_to :country,
               :foreign_key => "countries_id"
end

And use it like this:

country = Country.find(1)
p country.users

Upvotes: 3

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