Rails，模型关系子父答案

【问题标题】：Rails, model relationship child-parentRails，模型关系子父
【发布时间】：2018-01-28 00:17:25
【问题描述】：

我有一个简单的应用程序，我必须将学生与家长之间的关系描述为多对多，其中以下方法可行：

current_user.parents

current_user.children

目前我有以下

class User < ApplicationRecord
  has_many :parent_students
  has_many :students, through: :parent_students, class_name: "User"
  has_many :parents,  through: :parent_students, class_name: "User"
end

class ParentStudent < ApplicationRecord
    belongs_to :student, class_name: "User", foreign_key: "student_id"
    belongs_to :parent,  class_name: "User", foreign_key: "parent_id"
end

class CreateParentStudents < ActiveRecord::Migration[5.1]
  def change
    create_table :parent_students do |t|
        t.references :student, index: true, references: :users
        t.references :parent,  index: true, references: :users

      t.timestamps
    end
  end
end

知道这将如何工作吗？谢谢！

【问题讨论】：

标签： ruby-on-rails database-design

【解决方案1】：

可能这会有所帮助，用户内部的声明

class User < ActiveRecord::Base
  # as parent
    has_many: student_relations, foreign_key: :parent_id, class_name: "ParentStudent"
    has_many: students, through: :student_relations, source: :student
  # as student
    has_many: parent_relations, foreign_key: :student_id, class_name: "ParentStudent"
    has_many: parents, through: :parent_relations, source: :parent
end

class ParentStudent < ActiveRecord::Base
  belongs_to :student, foreign_key: "student_id", class_name: "User"
  belongs_to :parent,  foreign_key: "parent_id",  class_name: "User"
end

【讨论】：