Rails - Jun 2010 - belongs_to. Association methods don't pass data to DB

Hi.

I have a problem with the association methods which passed to a model
through a belongs_to declaration. Here''s an illustration of the issue:

GIVEN:

# migration
class CreateArticlesAndAuthorsTables < ActiveRecord::Migration
  def self.up
    create_table :articles do |t|
      t.text     :title
      t.integer :author_id
    end

    create_table :authors do |t|
      t.text :name
    end
  end

  def self.down
    drop_table :articles
    drop_table :authors
  end
end

# articles model
class Article < ActiveRecord::Base
  belongs_to :author
end

# authors model
class Author < ActiverRecord::Base
  has_many :articles
end

WHEN:
>> Article.create(:title => ''one'').author =
Author.create(:name => ''Pavel'')
>> Article.create(:title => ''two'').author =
Author.find(:first, :conditions => {:name => ''Pavel''})
THEN

sqlite> select * from authors;
     id = 1
name = Pavel

sqlite> select * from articles;
           id = 1
        title = ''one''
author_id = null

           id = 2
        title = ''two''
author_id = null

Why do I have null values instead of ids as foreign keys in the
articles table?

Thanks.

Ruby 1.9.2;
Rails 2.3.8.

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I got it.

It should to break the creation statements onto a few steps:

WHEN:
>> one = Article.new(:title => ''one'')
>> one.author = Author.new(:name => ''Pavel'')
>> one.save
>> two = Article.new(:title => ''two'')
>> two.author = Author.find(:first, :conditions => {:name =>
''Pavel''})
>> two.save
THEN:

sqlite> select * from authors;
     id = 1
name = Pavel

sqlite> select * from articles;
           id = 1
        title = ''one''
author_id = 1

           id = 2
        title = ''two''
author_id = 1

On 29 июн, 19:30, "P.A."
<shama...-PkbjNfxxIARBDgjK7y7TUQ@public.gmane.org>
wrote:
> Hi.
>
> I have a problem with the association methods which passed to a model
> through a belongs_to declaration. Here''s an illustration of the
issue:
>
> GIVEN:
>
> # migration
> class CreateArticlesAndAuthorsTables < ActiveRecord::Migration
>   def self.up
>     create_table :articles do |t|
>       t.text     :title
>       t.integer :author_id
>     end
>
>     create_table :authors do |t|
>       t.text :name
>     end
>   end
>
>   def self.down
>     drop_table :articles
>     drop_table :authors
>   end
> end
>
> # articles model
> class Article < ActiveRecord::Base
>   belongs_to :author
> end
>
> # authors model
> class Author < ActiverRecord::Base
>   has_many :articles
> end
>
> WHEN:
>
> >> Article.create(:title => ''one'').author =
Author.create(:name => ''Pavel'')
> >> Article.create(:title => ''two'').author =
Author.find(:first, :conditions => {:name => ''Pavel''})
>
> THEN
>
> sqlite> select * from authors;
>      id = 1
> name = Pavel
>
> sqlite> select * from articles;
>            id = 1
>         title = ''one''
> author_id = null
>
>            id = 2
>         title = ''two''
> author_id = null
>
> Why do I have null values instead of ids as foreign keys in the
> articles table?
>
> Thanks.
>
> Ruby 1.9.2;
> Rails 2.3.8.
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On 29 June 2010 17:29, P.A.
<shamaoke-PkbjNfxxIARBDgjK7y7TUQ@public.gmane.org>
wrote:
> I got it.
>
> It should to break the creation statements onto a few steps:
>
> WHEN:
>
>>> one = Article.new(:title => ''one'')
>
>>> one.author = Author.new(:name => ''Pavel'')
>
>>> one.save
>
>>> two = Article.new(:title => ''two'')
>
>>> two.author = Author.find(:first, :conditions => {:name =>
''Pavel''})
>
>>> two.save
Have a look at
author.articles.build
which will build a new article for an author and save some messing about.

Colin

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I was most interested about that methods which are added by belongs_to
declaration not has_many.

Anyway, thanks for help, Colin.

On 29 июн, 20:47, Colin Law
<clan...-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org>
wrote:
> On 29 June 2010 17:29, P.A.
<shama...-PkbjNfxxIARBDgjK7y7TUQ@public.gmane.org> wrote:
>
>
>
> > I got it.
>
> > It should to break the creation statements onto a few steps:
>
> > WHEN:
>
> >>> one = Article.new(:title => ''one'')
>
> >>> one.author = Author.new(:name => ''Pavel'')
>
> >>> one.save
>
> >>> two = Article.new(:title => ''two'')
>
> >>> two.author = Author.find(:first, :conditions => {:name
=> ''Pavel''})
>
> >>> two.save
>
> Have a look at
> author.articles.build
> which will build a new article for an author and save some messing about.
>
> Colin
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