class TeacherCourseGroup < ApplicationRecord belongs_to :course_group belongs_to :course, optional: true belongs_to :user belongs_to :course_member, optional: true scope :find_teacher_group_ids, lambda { |ids| where(course_group_id: ids) unless ids.blank?} scope :get_user_groups,lambda {|ids| where(user_id:ids)} validates_uniqueness_of :course_group_id, scope: :course_member_id def course_members self.course_group.course_members end end