Question

在我们的网站上，我们有一个用户个人资料页面，我们希望显示与该用户个人资料相关的所有微博。

在我们的微博表中，我们有一个belongs_to_id列和一个user_id（定义微博的来源）

我们正在尝试将belongs_to_id与user_id匹配。这样，当查看配置文件时，仅显示belongs_to_id与正在查看的配置文件的user_id匹配的微博。我们怎么能这样做？

class Micropost < ActiveRecord::Base
  attr_accessible :content, :belongs_to_id

  belongs_to :user


  validates :content, :presence => true, :length => { :maximum => 240 }
  validates :user_id, :presence => true

  default_scope :order => 'microposts.created_at DESC'

    # Return microposts from the users being followed by the given user.
    scope :from_users_followed_by, lambda { |user| followed_by(user) }

    private

      # Return an SQL condition for users followed by the given user.
      # We include the user's own id as well.
      def self.followed_by(user)
        following_ids = %(SELECT followed_id FROM relationships
                      WHERE follower_id = :user_id)
        where("user_id IN (#{following_ids}) OR user_id = :user_id",
          { :user_id => user })
    end
  end

UsersController：

class UsersController < ApplicationController
  before_filter :authenticate, :only => [:index, :edit, :update, :destroy]
  before_filter :correct_user, :only => [:edit, :update]
  before_filter :admin_user,   :only => :destroy

      def index
         @title = "All users"
         @users = User.paginate(:page => params[:page])
      end

      def show

          @user = User.find(params[:id])
          @microposts = @user.microposts.paginate(:page => params[:page])
          @title = @user.name
          @micropost  = current_user.microposts.build(params[:micropost])
      end

Answer 1

只有当你想要user_id AND belongs_to相同的帖子时，这是一个在MicroPost类中使用命名范围的方法：

micropost.rb

class MicroPost < ActiveRecord::Base
  scope :relevant_to_user, lambda{|i|
   where("user_id = ? AND belongs_to_id = ?", i, i)}
end

然后在控制器中：

def show
  @user = User.find(params[:id])
  @microposts = MicroPost.relevant_to_user(@user.id)
end

编辑：如果您只需要查找belongs_to_id与值匹配的微博（在本例中为current_user.id），请使用：

def show
  @microposts = MicroPost.where(:belongs_to_id=>current_user.id)
end

Answer 2

我不确定为什么Microposts belongs_to_id和user_id。但是如果你想找到belongs_to_id匹配给定用户ID的所有Micropost，你只需要：

@microposts = Micropost.find_all_by_belongs_to_id(@user.id)

按用户个人资料过滤微博

2 个答案: