I''m new to rails and ruby, and after trying to get this to work correctly for hours, I thought I''d give this forum an try. I''ve setup a trivial project just to mess around with Rails database naming conventions and associations. I''ve got a table called Pets, and a table called Types. Pets contains a list of pets, Parky the cat, Daisy the dog, etc, And Types contains a list of different pet types, dog - cat - fish - bird - etc. Pets table CREATE TABLE `pets` ( `id` int(11) NOT NULL auto_increment, `name` varchar(20) default NULL, `pet_id` int(11) default NULL, PRIMARY KEY (`id`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 Types table CREATE TABLE `types` ( `id` int(11) NOT NULL auto_increment, `pettype` varchar(11) default NULL, PRIMARY KEY (`id`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 What I want to do is to associate the pet_id from Pets with the id from types, and can do that in SQL like this: select pets.*, types.pettype from pets, types where pets.id = 1 and pets.pet_id = types.id In Rails, I have two models, 1 for pets, 1 for types class Type < ActiveRecord::Base belongs_to :pet end class Pet < ActiveRecord::Base has_one :type, :foreign_key => "id" end What I end up with is this SQL statement out of Rails: select pets.*, types.pettype from pets, types where pets.id = 1 and pets.pet_id = 1 Where 1 is the primary key (id) of the pets row. Just wondering what I''m doing wrong. Thanks! -- Posted via http://www.ruby-forum.com/.
I just made the same mistake a few hours ago. I ended up flipping the belongs_to: and has_one: in my Models and it works. So: class Type < ActiveRecord::Base has_one :pet end class Pet < ActiveRecord::Base belongs_to :type end You don''t need the foreign key either, rails handles that automagically. I have no idea if this is right, just that it does what I want it to do. On Jan 9, 2006, at 7:28 PM, David Mr. wrote:> I''m new to rails and ruby, and after trying to get this to work > correctly for hours, I thought I''d give this forum an try. > > I''ve setup a trivial project just to mess around with Rails database > naming conventions and associations. > > I''ve got a table called Pets, and a table called Types. > Pets contains a list of pets, Parky the cat, Daisy the dog, etc, And > Types contains a list of different pet types, dog - cat - fish - > bird - > etc. > > Pets table > CREATE TABLE `pets` ( > `id` int(11) NOT NULL auto_increment, > `name` varchar(20) default NULL, > `pet_id` int(11) default NULL, > PRIMARY KEY (`id`) > ) ENGINE=MyISAM DEFAULT CHARSET=latin1 > > Types table > CREATE TABLE `types` ( > `id` int(11) NOT NULL auto_increment, > `pettype` varchar(11) default NULL, > PRIMARY KEY (`id`) > ) ENGINE=MyISAM DEFAULT CHARSET=latin1 > > > What I want to do is to associate the pet_id from Pets with the id > from > types, and can do that in SQL like this: > > select pets.*, types.pettype > from pets, types > where pets.id = 1 > and pets.pet_id = types.id > > In Rails, I have two models, 1 for pets, 1 for types > > class Type < ActiveRecord::Base > belongs_to :pet > end > > class Pet < ActiveRecord::Base > has_one :type, :foreign_key => "id" > end > > What I end up with is this SQL statement out of Rails: > > select pets.*, types.pettype > from pets, types > where pets.id = 1 > and pets.pet_id = 1 > > Where 1 is the primary key (id) of the pets row. > > Just wondering what I''m doing wrong. > > Thanks! > > > > > > -- > Posted via http://www.ruby-forum.com/. > _______________________________________________ > Rails mailing list > Rails@lists.rubyonrails.org > http://lists.rubyonrails.org/mailman/listinfo/rails >- Bill
David Mr. wrote:> class Type < ActiveRecord::Base > belongs_to :pet > end >As a rule, I would stay away from using "type" as a model name or a column name. ''type'' is a reserved ruby keyword, and "type" columns are automagic for single table inheritance. You are likely to run into all sorts of wierdness if you use them outside of those contexts. _Kevin -- Posted via http://www.ruby-forum.com/.
Tried that and it still didn''t work for me.
This works, but not as pretty as just saying has_one and belongs_to :-(
def self.find_all_with_pettypes(j)
find :all,
{
:conditions => "id = ''#{j}''",
:joins => ''LEFT JOIN types ON pets.petid = types.petid''
}
end
Guess as I play with Rails more I might actually learn what I''m doing.
Thanks for they help!
Bill Pennington wrote:> I just made the same mistake a few hours ago. I ended up flipping the
> belongs_to: and has_one: in my Models and it works. So:
>
> class Type < ActiveRecord::Base
> has_one :pet
> end
>
> class Pet < ActiveRecord::Base
> belongs_to :type
> end
--
Posted via http://www.ruby-forum.com/.
I don''t think this is correct. You should have the belongs_to call in the class that contains the foreign key. So it does not make sense to say that Type belongs_to :pet. You had it right the first time. I agree with Kevin, however, I would stay away from "type" as a model name or attribute. Lance On 1/9/06, Bill Pennington <bill@norcalkayakanglers.com> wrote:> I just made the same mistake a few hours ago. I ended up flipping the > belongs_to: and has_one: in my Models and it works. So: > > class Type < ActiveRecord::Base > has_one :pet > end > > class Pet < ActiveRecord::Base > belongs_to :type > end > > You don''t need the foreign key either, rails handles that > automagically. I have no idea if this is right, just that it does > what I want it to do. > > On Jan 9, 2006, at 7:28 PM, David Mr. wrote: > > > I''m new to rails and ruby, and after trying to get this to work > > correctly for hours, I thought I''d give this forum an try. > > > > I''ve setup a trivial project just to mess around with Rails database > > naming conventions and associations. > > > > I''ve got a table called Pets, and a table called Types. > > Pets contains a list of pets, Parky the cat, Daisy the dog, etc, And > > Types contains a list of different pet types, dog - cat - fish - > > bird - > > etc. > > > > Pets table > > CREATE TABLE `pets` ( > > `id` int(11) NOT NULL auto_increment, > > `name` varchar(20) default NULL, > > `pet_id` int(11) default NULL, > > PRIMARY KEY (`id`) > > ) ENGINE=MyISAM DEFAULT CHARSET=latin1 > > > > Types table > > CREATE TABLE `types` ( > > `id` int(11) NOT NULL auto_increment, > > `pettype` varchar(11) default NULL, > > PRIMARY KEY (`id`) > > ) ENGINE=MyISAM DEFAULT CHARSET=latin1 > > > > > > What I want to do is to associate the pet_id from Pets with the id > > from > > types, and can do that in SQL like this: > > > > select pets.*, types.pettype > > from pets, types > > where pets.id = 1 > > and pets.pet_id = types.id > > > > In Rails, I have two models, 1 for pets, 1 for types > > > > class Type < ActiveRecord::Base > > belongs_to :pet > > end > > > > class Pet < ActiveRecord::Base > > has_one :type, :foreign_key => "id" > > end > > > > What I end up with is this SQL statement out of Rails: > > > > select pets.*, types.pettype > > from pets, types > > where pets.id = 1 > > and pets.pet_id = 1 > > > > Where 1 is the primary key (id) of the pets row. > > > > Just wondering what I''m doing wrong. > > > > Thanks! > > > > > > > > > > > > -- > > Posted via http://www.ruby-forum.com/. > > _______________________________________________ > > Rails mailing list > > Rails@lists.rubyonrails.org > > http://lists.rubyonrails.org/mailman/listinfo/rails > > > > > > - Bill > > _______________________________________________ > Rails mailing list > Rails@lists.rubyonrails.org > http://lists.rubyonrails.org/mailman/listinfo/rails >
So, I tried this once, and it didn''t work. I tried it again, and it did work. Now it''s working!!! Thanks, just needed to wrap my head around it for it to make sense (although it still seams backwards to me :-) Thanks again! Bill Pennington wrote:> I just made the same mistake a few hours ago. I ended up flipping the > belongs_to: and has_one: in my Models and it works. So: > > class Type < ActiveRecord::Base > has_one :pet > end > > class Pet < ActiveRecord::Base > belongs_to :type > end >-- Posted via http://www.ruby-forum.com/.