RubyonRails Activerecord嵌套模型问题的命名作用域标准

Question

我有以下表格（只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

我在模型中设置的关系如下：

员工.rb

has_many :appointments, :dependent => :destroy

预约.rb

has_many :appointment_uddss, :dependent => destroy
belongs_to :employee

任命_udds.rb

belongs_to :appointment
belongs_to :udds

udds.rb

has_many :appointment_uddss

---

所以我主要使用Employee模型，我试图在它的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，比如：

员工.rb

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

我希望调用Employee.with_udds来获取所有udd名称字段为非空的员工。这种关系对ActiveRecord来说太复杂了吗？还是我走错了路？

---

我还尝试将关系扩展到员工类中的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：

员工。有附加

返回一个空集（数据库中有udds.name！=null的数据）

Answer 1

明确列出包含：

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

Answer 2

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