Here is the final output I am able to achieve :



-----Models-----

PROJECTS

class Project &lt; ActiveRecord::Base
  attr_accessible  :name

  has_and_belongs_to_many :users
  belongs_to :project_manager, :class_name =&gt; "User"

end


USERS

class User &lt; ActiveRecord::Base
  attr_accessible :name, :project_id

  belongs_to :company
  belongs_to :owned_company, :class_name =&gt; "Company", :foreign_key =&gt; "owner_id"
  has_many :managed_projects, :class_name =&gt; "Project", :foreign_key =&gt; "project_manager_id"
  has_and_belongs_to_many :projects

end


COMPANIES

class Company &lt; ActiveRecord::Base
  attr_accessible :name

  has_many :users
  has_many :owners, :class_name =&gt; "User", :foreign_key =&gt; "owner_id"  

end


-----Tables &amp; Migrations-----

PROJECTS

class CreateProjects &lt; ActiveRecord::Migration
  def change
    create_table :projects do |t|
      t.string :name
      t.integer :project_manager_id

      t.timestamps
    end
  end
end


USERS

class CreateUsers &lt; ActiveRecord::Migration
  def change
    create_table :users do |t|
      t.string :name
      t.integer :project_id
      t.integer :owner_id

      t.timestamps
    end
  end
end


COMPANIES

class CreateCompanies &lt; ActiveRecord::Migration
  def change
    create_table :companies do |t|
      t.string :name

      t.timestamps
    end
  end
end


Projects - Users - Join Table

class CreateTableProjectsUsers &lt; ActiveRecord::Migration
  def self.up
    create_table :projects_users,:id =&gt; false  do |t|
      t.integer :project_id
      t.integer :user_id
    end
  end

  def self.down
     drop_table :projects_users
  end
end


How to implement Many to many relationship for USERS TABLE in ruby on rails without using any extra table?
I was planning to record months ago, with my electric guitar, and yesterday I got myself a guitar rig software and bought some 1/4 to 1/8 adapter jack so that I can plug in unto my laptop's mic hole.

Whenever I plug my guitar cable to the 1/4 to 1/8 adapter then to the laptop I can't hear any sound (past the clicking sound you hear) but when I plug the cable almost halfway of the adapter's body (before the clicking sound) I can hear sound when I play and there's some loud buzzing sound involved.

Any explanations as to why this is happening? 
