RubyOnRails

RubyOnRails - 无法通过关联在has_many中执行where语句(RubyOnRails - Can't do a where statment in a has_many through relatiation)

所以我是RoR的新手，我似乎无法做出选择的地方。 这些是以下类：

型号：

class List < ActiveRecord::Base has_many :list_categorization has_many :category, :through => :list_categorization end class ListCategorization < ActiveRecord::Base attr_accessible :category_id, :list_id belongs_to :category belongs_to :list end class Category < ActiveRecord::Base attr_accessible :name has_many :list_categorizations has_many :lists, :through => :list_categorizations end

我要做的是选择一个给定类别的列表。 我尝试使用以下代码在list_controler中对此进行简化版本：

class ListsController < ApplicationController @lists = List.where("category.id = ?", 2) end end

并通过以下观点：

<ul class="lists"> <%= render @lists%> </ul>

然后出现以下错误：

列表中的ActiveRecord :: StatementInvalid＃index_where

SQLite3 :: SQLException：没有这样的列：category.id：SELECT“lists”。* FROM“lists”WHERE（category.id = 2）ORDER BY lists.created_at DESC

我究竟做错了什么？ 谢谢和最好的问候。

So I'm new to RoR and i can't seem to do a select where statment. These are the following classes:

The models:

class List < ActiveRecord::Base has_many :list_categorization has_many :category, :through => :list_categorization end class ListCategorization < ActiveRecord::Base attr_accessible :category_id, :list_id belongs_to :category belongs_to :list end class Category < ActiveRecord::Base attr_accessible :name has_many :list_categorizations has_many :lists, :through => :list_categorizations end

And what i'm trying to do is to select a list with a given category. I tried to do a simplified version of this in the list_controler with the following code:

class ListsController < ApplicationController @lists = List.where("category.id = ?", 2) end end

And with the following view:

<ul class="lists"> <%= render @lists%> </ul>

Then the following error apears:

ActiveRecord::StatementInvalid in Lists#index_where

SQLite3::SQLException: no such column: category.id: SELECT "lists".* FROM "lists" WHERE (category.id = 2) ORDER BY lists.created_at DESC

What am I doing wrong? Thanks and best regards.

最满意答案

@lists = Category.find(2).lists @lists = Category.find(2).lists