Question

I’m a little lost with mongoid queries. I have a user that has one company.
Here is the model

class Company
    include Mongoid::Document
    include Mongoid::Timestamps

    field :name,                        :type => String
    field :description,         :type => String
    field :order_minimun,       :type => Float

    belongs_to :user

  def candidate_users
    User.where(:company_id => nil)
  end

end

class User
  include Mongoid::Document
    include Mongoid::Timestamps

    ROLES = %w[admin company_owner customer]

  # Include default devise modules. Others available are:
  # :token_authenticatable, :confirmable,
  # :lockable, :timeoutable and :omniauthable
  devise :database_authenticatable, :registerable,
         :recoverable, :rememberable, :trackable, :validatable, :omniauthable

  ## Database authenticatable
  field :email,              :type => String, :default => ""
  field :encrypted_password, :type => String, :default => ""

  validates_presence_of :email
  validates_presence_of :encrypted_password

  ## Recoverable
  field :reset_password_token,   :type => String
  field :reset_password_sent_at, :type => Time

  ## Rememberable
  field :remember_created_at, :type => Time

  ## Trackable
  field :sign_in_count,      :type => Integer, :default => 0
  field :current_sign_in_at, :type => Time
  field :last_sign_in_at,    :type => Time
  field :current_sign_in_ip, :type => String
  field :last_sign_in_ip,    :type => String

    field :name,               :type => String
    field :last_name,          :type => String
    validates_presence_of :name
    #validates_uniqueness_of :name, :email, :case_sensitive => false

    field :roles_list,                  :type => Array , :default => ['customer']
    validates_uniqueness_of :email, :case_sensitive => false

    has_one :company
end

I want to list of the users that not has a company, and the user that owns the company instance.

My first attempt (just of the users which don’t have a company):

  def candidate_users
    User.where(:company_id => nil)
  end

the somethig like this

def candidate_users
    User.any_of(:company_id => self.id, :company_id => nil)
  end

But I have no luck, that returns all the users.

Someone can helpme with this query?

Thanks in advance.

Answer 1

With mongoid, the foreign field is always on the side of the belongs_to association. So Company objects will have a user_id field, but User objects won’t have a company_id field. So it is “normal” for your queries to return all users

Since there is no notion of join in mongodb, you can achieve this either by reversing the association (user belongs_to company, company has_one user), or you can do two queries :

# First, finding ids of users that have a company
ids = Company.excludes(user_id: nil).only(:_id).map(&:id)

# Then, find users whose ids are not in that array
users = User.not_in(_id: ids)

Still keeping the part about any_of:

any_of is doing a $or query for all hashes arguments. By doing User.any_of(:company_id => self.id, :company_id => nil), you’re supplying only array, which is the same as User.where(:company_id => self.id, :company_id => nil). What I think you want to do is User.any_of({:company_id => self.id}, {:company_id => nil})