Mongoid example generating possibly excessive db queries

mongoid_test.rb

# Monogid Models
class Employee
  include Mongoid::Document
  include Mongoid::Timestamps

  field :ssid, type: String
  field :name, type: String

  index :name

  belongs_to :department, index: true
  belongs_to :company, index: true

  validates :ssid, uniqueness: true

end

class Department
  include Mongoid::Document
  include Mongoid::Timestamps

  field :name, type: String
  field :employee_count, type: Integer

  index :name

  has_many :employees, dependent: :destroy
  belongs_to :company, index: true
end

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

  field :name, type: String
  field :employee_count, type: Integer

  index :name

  has_many :departments, dependent: :destroy
  has_many :employees, dependent: :destroy

end


# Code to run in console or wherever.
# Note: the real-world case all data comes from a data file containing all the data used to generate the association "tree". Imagine a csv with each row containing an employee and the names of their department and company. Also imaging some more updates being done when an existing dept or corp is found.

employee = Employee.new(ssid:"123", name:"Person One")

department = Department.first(:conditions => { :name => "Sales" })
if department.nil?
  department = Department.new
  department.name = "Sales"
else
  employee.company = department.company
end
employee.department = department


company = Company.first(:conditions => { :name => "Apple" })
if company.nil?
  company = Company.new
  company.name = "Apple"
end
employee.department.company = company if employee.department.company.nil?
employee.company = company

employee.department.save
employee.department.inc(:employee_count, 1)
employee.department.company.save
employee.department.company.inc(:employee_count, 1)
employee.save