Ruby on rails RubyonRailsActiveRecord命名范围标准关于嵌套模型问题

以下表格仅显示主键和外键以及udds表格中的名称：

employee    appointment    appointment_udds    udds
--------    -----------    ----------------    ----
id          id             id                  id
            employee_id    appointment_id      name
                           udds_id

我在模型中设置了如下关系：

employee.rb

appointment.rb

预约_udds.rb

udds.rb

因此，我主要使用Employee模型，并尝试在其模型中创建一个命名范围，以获取所有具有非空udds名称的记录，如下所示：

employee.rb

我希望调用Employee.with_udds来获取所有UDD中包含非空名称字段的员工。这种关系对ActiveRecord来说太复杂了，还是我走错了方向

我还尝试将关系扩展到employee类中的udds表：

class Employee < ActiveRecord::Base
  acts_as_audited
  has_many :appointments, :dependent => :destroy
  has_many :appointment_uddss, :through => :appointments
  has_many :uddss, :through => :appointment_uddss

  named_scope :with_udds, :include => :uddss, :conditions => "udds.name IS NOT NULL"

然后在控制台中：

带udds的Employee.com

---

返回一个空集。udds.name！=db中为空，明确列出包含项：

:include => { :appointments => { :appointment_uddss => :uddss } }

试试这个：

class Employee < ActiveRecord::Base
  acts_as_audited
  has_many :appointments, :dependent => :destroy
  has_many :appointment_uddss, :through => :appointments
  has_many :uddss, :through => :appointment_uddss

  scope :with_udds, where("udds.name IS NOT NULL").includes(:udds)
end

---

在Rails 3中，不推荐传递参数散列。1@CaleyRails3.0中不推荐使用命名的_范围，因此我假设这个问题适用于2.x

has_many :appointment_uddss

named_scope :with_udds, :include => :uddss, :conditions => "udds.name IS NOT NULL"

class Employee < ActiveRecord::Base
  acts_as_audited
  has_many :appointments, :dependent => :destroy
  has_many :appointment_uddss, :through => :appointments
  has_many :uddss, :through => :appointment_uddss

  named_scope :with_udds, :include => :uddss, :conditions => "udds.name IS NOT NULL"

:include => { :appointments => { :appointment_uddss => :uddss } }

class Employee < ActiveRecord::Base
  acts_as_audited
  has_many :appointments, :dependent => :destroy
  has_many :appointment_uddss, :through => :appointments
  has_many :uddss, :through => :appointment_uddss

  scope :with_udds, where("udds.name IS NOT NULL").includes(:udds)
end