评论家的政策范围有很多通过关系

Question

第一贴这里，所以我希望它是有道理的，但我一直在旋转我的车轮太久了。 首先是一个小背景。我正在构建一个包含3个模型的Wiki应用程序：用户，Wiki和协作（连接表）。

我正在使用Devise和Pundit，并有4类用户应根据他们的状态查看维基的不同子集。

这里的规则：

• 公众用户（未登录） - 应查看（无需编辑）仅公共维基 （：隐藏=>假）
• 身份验证的用户（：角色=>“标准“） - 应 查看，编辑&仅删除公共维基。
• 高级用户（：角色=> “溢价”） - 查看，编辑，删除公共wiki和创造 私人维基的能力（：隐藏=>真），并添加合作者的私人 维基这给他们编辑维基的权利。
• Admin（：role =>“admin”）完全控制所有记录。

所以我在政策范围内（用户检查状态）一个漫长scope.joins条件我维基索引视图给予CURRENT_USER的基于角色维基列表的一个子集。

信念使喷出了这样的错误：

Started POST "/__better_errors/59802a57d82fd17e/variables" for 127.0.0.1 at 2014-12-02 09:05:41 -0800 
    Wiki Load (0.4ms) SELECT "wikis".* FROM "wikis" INNER JOIN "collaborations" ON "collaborations"."wiki_id" = "wikis"."id" WHERE (hide = 'f' or user_id = 2 or collaborations.user_id = 2) 
SQLite3::SQLException: ambiguous column name: user_id: SELECT "wikis".* FROM "wikis" INNER JOIN "collaborations" ON "collaborations"."wiki_id" = "wikis"."id" WHERE (hide = 'f' or user_id = 2 or collaborations.user_id = 2) 

这里的政策

class WikiPolicy < ApplicationPolicy 

    # What collections a user can see users `.where` 
    class Scope < Scope 

    def resolve 
     if user && user.role == 'admin' 
     scope.all 
     elsif user 
     scope.joins(:collaborations).where("hide = :hide or user_id = :owner_id or collaborations.user_id = :collaborator_id", {hide: false, owner_id: user.id, collaborator_id: user.id}) 
     else 
     scope.where hide: false 
     end 
    end 
    end 


    #Policies are boolean logic true or false to determine if a user has access to a controller action. 
    def update? 
    (user && user.role == 'admin') || (user && record.users.pluck(:id).include?(user.id)) || (user && user.id == record.owner.id) 
    end 

    def show? 
    (user.present? && user.admin?) or not record.hide? 
    end 

    def premium? 
    user.admin? or user.premium? 
    end 

    def edit? 

    end 

end  

我的模型

class Wiki < ActiveRecord::Base 
    belongs_to :user 
    has_many :collaborations, dependent: :destroy 
    has_many :users, through: :collaborations 

    def owner 
    user 
    end 

    def collaborators 
    users 
    end 

    validates :title, length: { minimum: 5 }, presence: true 
    validates :body, length: { minimum: 20 }, presence: true 

end 

class User < ActiveRecord::Base 
    devise :database_authenticatable, :registerable, 
     :recoverable, :rememberable, :trackable, :validatable, :confirmable 
    has_many :wikis 
    has_many :collaborations 
    has_many :cowikis, through: :collaborations, source: :wiki 

    after_initialize :init 

    def admin? 
    role == 'admin' 
    end 

    def premium? 
    role == 'premium' 
    end 

    def standard? 
    role == 'standard' 
    end 

private 
    def init 
    if self.new_record? && self.role.nil? 
     self.role = 'standard' 
    end 
    end 
end 

class Collaboration < ActiveRecord::Base 
    belongs_to :user 
    belongs_to :wiki 
end 

维基控制器

class WikisController < ApplicationController 
    def index 
    @wikis = policy_scope(Wiki) 
    # authorize @wikis 
    end 

    def show 
    @wiki = Wiki.find(params[:id]) 
    authorize @wiki 
    end 

    def new 
    @wiki = Wiki.new 
    authorize @wiki 
    end 

    def create 
    @wiki = Wiki.new(wiki_params) 
    authorize @wiki 
    if @wiki.save 
     flash[:notice] = "Post was saved." 
     redirect_to @wiki 
    else 
     flash[:error] = "There was an error saving the post. Please try again." 
     render :new 
    end 
    end 

    def edit 
    @user = current_user 
    @users = User.all 
    @wiki = Wiki.find(params[:id]) 
    authorize @wiki 
    end 

def update 
    @wiki = Wiki.find(params[:id]) 
    authorize @wiki 
    @wiki.collaborators = params[:wiki][:user_ids] 
    if @wiki.update_attributes(wiki_params) 
    flash[:notice] = "Post was updated." 
    redirect_to @wiki 
    else 
    flash[:error] = "There was an error saving the post. Please try again." 
    render :edit 
    end 
end 

    def destroy 
    @wiki = Wiki.find(params[:id]) 
    authorize @wiki 
    title = @wiki.title 

    if @wiki.destroy 
     flash[:notice] = "\"#{title}\" was deleted successfully." 
     redirect_to wikis_path 
    else 
     flash[:error] = "There was an error deleting the wiki." 
     render :show 
    end 
    end 

    private 

    def wiki_params 
    params.require(:wiki).permit(:title, :body, :hide) 
    end 
end 

我希望你是不是不知所措的代码，但我想提供尽可能多的信息成为可能。

感谢您的帮助！

哦，这是最有可能的违规代码，但我包括上下文的一切。

scope.joins(:collaborations).where("hide = :hide or user_id = :owner_id or collaborations.user_id = :collaborator_id", {hide: false, owner_id: user.id, collaborator_id: user.id}) 

Answer 1

这是错误信息的最有价值的部分：

SQLite3::SQLException: ambiguous column name: user_id 

当SQL结果集具有相同名称的多个列可能发生的不明确的列名错误。在这种情况下，列是user_id。

user_id列位于wiki表和协作表中。这两个表都用在SQL查询中。

这里的SQL代码片段引起的问题：

# DB can't figure out which table "user_id = 2" refers to: 
WHERE (hide = 'f' or user_id = 2 or collaborations.user_id = 2) 

我们需要指定对user_id列的表名前缀。

要做到这一点，请尝试更改此行WikiPolicy：

scope.joins(:collaborations) 
    .where("hide = :hide or user_id = :owner_id or collaborations.user_id = :collaborator_id", {hide: false, owner_id: user.id, collaborator_id: user.id}) 

到：

scope.joins(:collaborations) 
    .where("hide = :hide or wikis.user_id = :owner_id or collaborations.user_id = :collaborator_id", {hide: false, owner_id: user.id, collaborator_id: user.id})