ActiveRecord的和关联排序 [英] ActiveRecord and sorting on association

问题描述

我有这样一个简单的AR协会：

 问题的has_many：答案

答belongs_to的：问题

同
  `question_id` INT（11）NOT NULL，
  `is_accepted` TINYINT（1）DEFAULT NULL，
 

在答案。我只有一个is_accpeted答案，想知道是否有一个简单的排序的顶端（只是一个数量级）？

THX

编辑： 这里是我的回答类：

 类答：LT;的ActiveRecord :: Base的
    belongs_to的：问题
结束
 

解决方案

答案是在你的架构

 `is_accepted` TINYINT（1）
 

对于很多数据库，ActiveRecord的商店布尔值真和假为 1 和 0

所以

 问题= Question.find（23）
questions.answers.order（is_accepted DESC）
 

应该做你想要的。

您还可以添加此为默认顺序。

 类问题
  的has_many：答案：为了=＆GT; is_accepted DESC＃导轨3
  的has_many：答案 - ＆GT; {令is_accepted DESC}＃导轨4
结束
 

现在 question.answers 将总是以is_accepted之首。

I have a simple AR association like this:

Question    has_many :answers

Answer      belongs_to :question

with
  `question_id` int(11) NOT NULL,
  `is_accepted` tinyint(1) DEFAULT NULL,

in the answer. I'll have only one is_accpeted answer and am wondering if there is an easy to sort that to the top (just an order by)?

thx

Edit: here is my Answer class:

class Answer < ActiveRecord::Base
    belongs_to :question 
end 

解决方案

the answer is in your schema

`is_accepted` tinyint(1)

For many databases, ActiveRecord stores booleans true and false as 1 and 0

so

question = Question.find(23)
questions.answers.order("is_accepted DESC")

should do what you want.

You can also add this as the default order.

class Question
  has_many :answers, :order => "is_accepted DESC" # rails 3
  has_many :answers, -> { order "is_accepted DESC" } # rails 4
end

now question.answers will always start with the "is_accepted" first.

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