The counter is not working as I expected in has_many :through relationship.
I have very simple models. The Article and Pubtype models are in many-to-many relationship, which is stored in the ArticleType model.
Here are the models:
class Article < ActiveRecord::Base has_many :article_types has_many :pubtypes, :through => :article_types end
class Pubtype < ActiveRecord::Base has_many :article_types has_many :articles, :through => :article_types end
class ArticleType < ActiveRecord::Base belongs_to :article belongs_to :pubtype end
Here is the actual schema:
ActiveRecord::Schema.define(:version => 8) do ... create_table "article_types", :force => true do |t| t.column "article_id", :integer t.column "pubtype_id", :integer end
create_table "articles", :force => true do |t| t.column "title", :text end
create_table "pubtypes", :force => true do |t| t.column "title", :string t.column "articles_count", :integer, :default => 0, :null => false end ... end
And here is the weird situation ('>>' is irb and '##' is log):
pubtype = Pubtype.find(1)
=> #<Pubtype:0x337a728 @attributes={"title"=>"News", "id"=>"1", "articles_count"=>"1"}>
## Pubtype Load (0.000559) SELECT * FROM pubtypes WHERE (pubtypes.id = 1)
pubtype.articles_count
=> 1
## Article Load (0.008023) SELECT articles.* FROM articles INNER JOIN article_types ON articles.id = article_types.article_id WHERE ((article_types.pubtype_id = 1))
Here, the already loaded "articles_count" attribute value of the pubtype object is not used and a actual select sql was called to count the number of articles that belong to the pubtype. It seems that rails intercepted the method call and did an unnecessary magic.
Is this an intentional behaviour for some good reason?
I'm running on the edge rails.
About your application's environment Ruby version 1.8.5 (i686-darwin8.8.1) RubyGems version 0.9.0 Rails version 1.2.0 Active Record version 1.14.4 Action Pack version 1.12.5 Action Web Service version 1.1.6 Action Mailer version 1.2.5 Active Support version 1.3.1 Edge Rails revision 5717 Application root /Users/joon/Sites/clickstream Environment development Database adapter mysql Database schema version 8
