我试图在自联接关联中的列上添加计数器缓存.
我有两个型号用户和以下.用户拥有关注者和关注者,他们来自用户表本身.
我有两个型号用户和以下.用户拥有关注者和关注者,他们来自用户表本身.
User.rb has_many :followings has_many :followers,:through => :followings has_many :followees,:through => :followings Following.rb class Following < ActiveRecord::Base attr_accessible :followee_id,:follower_id belongs_to :follower,:class_name => "User" belongs_to :followee,:class_name => "User" end
现在我想在追随者和追随者上添加计数器缓存.我在用户表中有followers_count和followees_count列.
我试过了
belongs_to :follower,:class_name => "User",:counter_cache => true
但是这不会返回用户表中的任何数据.
任何帮助,将不胜感激.
解决方法
很久以前,但是
User.rb
class User < ActiveRecord::Base has_many :followings_as_follower,class_name: 'Following',foreign_key: 'follower_id',dependent: :destroy has_many :followings_as_followee,foreign_key: 'followee_id',dependent: :destroy has_many :followers,through: :followings_as_followee,source: :follower has_many :followees,through: :followings_as_follower,source: :followee def follow?(user) followees.reload.include? user end def follow(user) return if follow?(user) followings_as_follower.create(followee: user) end def unfollow(user) return unless follow?(user) followings_as_follower.where(followee: user).first.destroy end end
Following.rb
class Following < ActiveRecord::Base belongs_to :follower,class_name: 'User',counter_cache: :followees_count belongs_to :followee,counter_cache: :followers_count validates :follower,presence: true validates :followee,uniqueness: { scope: [:follower,:followee] } end