Question

I have two tables, users and groups. An user owns a group and can be apart of multiple groups. A group belongs to one user and can have many users.

Thus for my user model I have

has_and_belongs_to_many :groups
has_many :groups

While for my group model I have

has_and_belongs_to_many :users
belongs_to :user

I also have a join table in my migrations..

def change
  create_table :groups_users, :id => false do |t|
    t.integer :group_id
    t.integer :user_id
  end
end

My question is does this make sense? I feel like I’m doing something wrong by having has_many and belongs_to on top of has_and_belongs_to_many.

Answer 1

The way I would approach this, and this is my own personal methodology, is with 3 tables/models like so:

group_user.rb

class GroupUser < ActiveRecord::Base
  attr_accessible :user_id, :group_id

  belongs_to :group
  belongs_to :user
end

group.rb

class Group < ActiveRecord::Base
  attr_accessible :owner_id

  validates_presence_of :owner_id

  has_many :group_users
  has_many :users, through: :group_users
end

user.rb

class User < ActiveRecord::Base
  attr_accessible :some_attributes

  has_many :group_users
  has_many :groups, through: :group_users
end

Then, whenever you create a Group object, the User that created it would have its id placed in the owner_id attribute of Group and itself into the GroupUser table.