Rails - Jun 2005 - Joins - belongs_to and has_and_belongs_to_many in same class?

Hi,

Probably a newbie question, but I''ve got the following setup for a
Rails
application at the moment

Ruby 1.8.2, Rails 0.12.1, Debian unstable, Apache mod_rewrite/FastCGI

Table: members

CREATE TABLE `members` (
  `id` int(11) NOT NULL auto_increment,
  `organisation_id` int(11) default NULL,
  `username` varchar(32) NOT NULL default '''',
  `password` varchar(128) NOT NULL default '''',
  `displayname` varchar(255) NOT NULL default '''',
  `title` varchar(255) default NULL,
  `email` varchar(255) NOT NULL default '''',
  `isadmin` int(11) NOT NULL default ''0'',
  `comments` text,
  `created_on` datetime NOT NULL default ''0000-00-00
00:00:00'',
  `updated_on` datetime NOT NULL default ''0000-00-00
00:00:00'',
  PRIMARY KEY  (`id`),
) TYPE=InnoDB;

table: projects

CREATE TABLE `projects` (
  `id` int(11) NOT NULL auto_increment,
  `organisation_id` int(11) NOT NULL default ''0'',
  `member_id` int(11) NOT NULL default ''0'',
  `projectname` varchar(255) NOT NULL default '''',
  `created_on` datetime NOT NULL default ''0000-00-00
00:00:00'',
  `updated_on` datetime NOT NULL default ''0000-00-00
00:00:00'',
  PRIMARY KEY  (`id`)
) TYPE=InnoDB;

table: members_projects

CREATE TABLE `members_projects` (
  `member_id` int(11) NOT NULL default ''0'',
  `project_id` int(11) NOT NULL default ''0''
) TYPE=InnoDB;

I''ve got models/controllers/views for member and project.  The problem
I''ve got is I want the member_id in projects to hold the owner, but
also
list the people who are involved in the project via the members_projects
table.

model: member

class Member < ActiveRecord::Base
  validates_uniqueness_of :username
  validates_uniqueness_of :email
  belongs_to :organisation
  has_many :project
  has_and_belongs_to_many :project
  def self.authenticate(username,password)
    find(:first, :conditions => ["username = ? and password
?",username,password])
  end
end

model: project

class Project < ActiveRecord::Base
  belongs_to :organisation
  belongs_to :member
  has_and_belongs_to_many :member
end

This gives me an Action Controller Exception - before the
has_and_belongs_to_many were added it was working fine.  Question is, can
I get it working like this with just a change to the model, or can I
rename member_id to owner_id in the table and change the model/views to
support this, or is there another way of doing it that''s better?

Cheers

Kevin

>
> I''ve got models/controllers/views for member and project.  The
problem
> I''ve got is I want the member_id in projects to hold the owner,
but also
> list the people who are involved in the project via the members_projects
> table.
>
> model: member
>
> class Member < ActiveRecord::Base
>   validates_uniqueness_of :username
>   validates_uniqueness_of :email
>   belongs_to :organisation
>   has_many :project
>   has_and_belongs_to_many :project
>   def self.authenticate(username,password)
>     find(:first, :conditions => ["username = ? and password >
?",username,password])
>   end
> end
>
> model: project
>
> class Project < ActiveRecord::Base
>   belongs_to :organisation
>   belongs_to :member
>   has_and_belongs_to_many :member
> end
>
> This gives me an Action Controller Exception - before the
> has_and_belongs_to_many were added it was working fine.  Question is, can
> I get it working like this with just a change to the model, or can I
> rename member_id to owner_id in the table and change the model/views to
> support this, or is there another way of doing it that''s better?
>
I think you could do

class Owner < Member
 has_many :projects
end

class Member
 habtm :projects
end

class Project
 habtm :members, :foreign_key => "project_id"
 belongs_to :owner, :foreign_key => "owner_id"
end

This would differentiate between the roles of a member and should eliminate 
the exception.

stephan

Thanks for your help, that worked a treat!

Kevin
> I think you could do
>
> class Owner < Member
>  has_many :projects
> end
>
> class Member
>  habtm :projects
> end
>
> class Project
>  habtm :members, :foreign_key => "project_id"
>  belongs_to :owner, :foreign_key => "owner_id"
> end
>
> This would differentiate between the roles of a member and should
> eliminate
> the exception.
>
> stephan
>
>