作用域与:has_many:through关联的连接
class Users < ActiveRecord::Base has_many :meetings, :through => :meeting_participations has_many :meeting_participations end class Meetings < ActiveRecord::Base has_many :users, :through => :meeting_participations has_many :meeting_participations end class MeetingParticipations < ActiveRecord::Base belongs_to :user belongs_to :meeting scope :hidden, where(:hidden => true) scope :visible, where(:hidden => false) end hidden是m2m关联表中的一个额外的布尔列。鉴于某些Users情况current_user,我想做 current_user.meetings.visible 它将检索Meetings该hidden列所在的用户是其参与者的集合false。我得到的最接近的是将以下范围添加到Meetings类中 scope :visible, joins(:meeting_participations) & …