Question

我学会了如何使用来自这个问题的关系查询。

Ruby on Rails where query with relations

但是，我仍然无法使用这种嵌套案例。如何使Summaries控制器索引工作？

模型

User
  has_many :projects, dependent: :destroy
  has_many :reasons, through: :projects
  has_many :summaries, through: :projects, source: :reasons
  has_many :entries, through: :projects

Project
  belongs_to :user
  has_many :reasons
  has_many :entries, through: :reasons

Reasons
  belongs_to :project
  has_many :entries, dependent: :destroy 
  has_many :summaries, dependent: :destroy 

Summary
  belongs_to :reason

Entry
  belongs_to :reason

EntriesController

  # GET /entries
  def index
    entries     = current_user.entries
    updated_at  = params[:updated_at]

    # Filter with updated_at for reloading from mobile app
    if updated_at.present?

      # THIS WORKS!!!!!!!!!!!!!
      entries = entries.joins(:reason).where("reasons.updated_at > ?", Time.at(updated_at.to_i))

    # Get all non deleted objects when logging in from mobile app
    else
      entries = entries.where(deleted: false)
    end

    render json: entries
  end

SummariesController

  # GET /summaries
  def index
    summaries   = current_user.summaries
    updated_at  = params[:updated_at]

    # Filter with updated_at for reloading from mobile app
    if updated_at.present?



      #THIS DOES NOT WORK, what can I do?????
      summaries = summaries.joins(:reason).where("reasons.updated_at > ?", Time.at(updated_at.to_i))



    # Get all non deleted objects when logging in from mobile app
    else
      summaries = summaries.where(deleted: false)
    end

    render json: summaries
  end

iOS上的@Error登录

错误：错误Domain = com.alamofire.error.serialization.response Code = -1011“请求失败：内部服务器错误（500）”UserInfo = {NSUnderlyingError = 0x1481b9030 {Error Domain = com.alamofire.error.serialization。响应代码= -1016“请求失败：不可接受的内容类型：text / html”

@错误登录Heroku

[1m [36mUser Load（2.0ms）[0m [1mSELECT“users”。* FROM“users”ORDER BY“users”。“id”ASC LIMIT 1 [0m 2016-04-30T07：48：18.909397 + 00:00 app [web.1]：4ms完成500内部服务器错误（ActiveRecord：2.0ms） 2016-04-30T07：48：18.910250 + 00:00 app [web.1]：ActiveRecord :: ConfigurationError（在Reason上找不到名为'reason'的关联;也许你拼错了吗？）：

Answer 1

首先，您以非常随意的方式引用reasons。 User has_many reasons到projects，为什么不走这条路？

current_user.joins(:reasons).where(reasons.updated_at > ?", updated_at)

其次，更具体地说明了您的错误：您的关系定义has_many :summaries, through: :projects, source: :reasons似乎已被打破，因为projects没有任何summaries。

考虑在has_many :summaries, through: :reasons模型中添加Project，然后在has_many :summaries, through: :projects中使用User。

Ruby on Rails，其中查询具有嵌套关系

1 个答案: