Ruby on rails 3 两个相同的模型属于关联

我有一个模型

接触点

，它有许多

系统
。从
系统
方面，我想将
接触点
确定为
技术经理
或
项目经理
（或两者兼而有之）。但仍然只在数据库中保留
接触点
1次

我的尝试如下：

class System < ActiveRecord::Base
  belongs_to :project_manager, :class_name => 'PointOfContact'
  belongs_to :technical_manager, :class_name => 'PointOfContact'
end

class PointOfContact < ActiveRecord::Base
  has_many :systems
end

多亏了RailsForum.com上的jamesw：找到了解决方案

class System < ActiveRecord::Base
  belongs_to :project_manager, :class_name => 'PointOfContact', :foreign_key => 'project_manager_id'
  belongs_to :technical_manager, :class_name => 'PointOfContact', :foreign_key => 'technical_manager_id'
end

class PointOfContact < ActiveRecord::Base
  has_many :project_managed_systems, :class_name => 'System', :foreign_key => 'project_manager_id'
  has_many :technical_managed_systems, :class_name => 'System', :foreign_key => 'technical_manager_id'
end

类系统'PointOfContact'，：外键=>'project\u manager\u id'
属于：技术经理，：class\u name=>'PointOfContact'，：foreign\u key=>'technical\u manager\u id'
结束
类PointOfContact'System'，：外键=>'project\u manager\u id'
有很多：技术管理系统，：类名称=>'System'，：外键=>'technical\u manager\u id'
结束
来自Rails文档：





注释示例：

# Employee class with two Employee associations
class Employee < ApplicationRecord

  # Employees I manage
  has_many :subordinates, class_name: "Employee",
                          foreign_key: "manager_id"

  # Employee that manages me
  # NOTE: with :manager reference name, foreign_key defaults to "manager_id",
  # hence it is not needed as above. Favor "convention over configuration".
  belongs_to :manager, class_name: "Employee"
end

#具有两个员工关联的员工类
类员工<应用程序记录
#我管理的员工
有很多：下属，班名：“员工”，
外键：“经理id”
#管理我的员工
#注意：使用：manager reference name，外键默认为“manager\u id”，
#因此，不需要如上所述。赞成“约定胜于配置”。
属于：经理，班名：“员工”
结束
有关的更多详细信息：通过上的关系
# Employee class with two Employee associations
class Employee < ApplicationRecord

  # Employees I manage
  has_many :subordinates, class_name: "Employee",
                          foreign_key: "manager_id"

  # Employee that manages me
  # NOTE: with :manager reference name, foreign_key defaults to "manager_id",
  # hence it is not needed as above. Favor "convention over configuration".
  belongs_to :manager, class_name: "Employee"
end