如何处理两个嵌套的兄弟姐妹，接下来是 to_json？答案

【问题标题】：How to handle two nested siblings, with to_json next?如何处理两个嵌套的兄弟姐妹，接下来是 to_json？
【发布时间】：2013-06-01 19:58:41
【问题描述】：

to_json ActiveRecord 文档说 this 用于处理两个嵌套模型，其中 cmets 嵌套在帖子中：

  konata.to_json(:include => { :posts => {
                                 :include => { :comments => {
                                               :only => :body } },
                                 :only => :title } })
  # => {"id": 1, "name": "Konata Izumi", "age": 16,
        "created_at": "2006/08/01", "awesome": true,
        "posts": [{"comments": [{"body": "1st post!"}, {"body": "Second!"}],
                   "title": "Welcome to the weblog"},
                  {"comments": [{"body": "Don't think too hard"}],
                   "title": "So I was thinking"}]}

假设我有两个嵌套的模型，但没有深度嵌套。可以说它是用户模型和 cmets 模型。嵌套模型就是我所说的嵌套兄弟。

我希望我的 json 看起来像这样：

x = { 
    "Blog": {
        "Comments": [
         {"id":1,"name":"John Doe"},
         {"id":2,"name":"Don Joeh"}
        ],
        "User": [
         {"id":2,"company":"ACME"},
         {"id":4,"company":"BUD"}]
    }
}

当我两次使用 include 方法时，我最终得到的是一系列深度嵌套的 json，其中用户是 cmets 的子级。怎么了？！

data.to_json(
        :include => { :blog => {
          :include => [{ :comments => {
            :except => SKIPPED_COLUMNS,
            :methods => [:_type]
          }},
          { :users => {
              :except => SKIPPED_COLUMNS,
              :methods => [:_type]
          }}],
          :except => SKIPPED_COLUMNS,
          :methods => [:_type]
        }},
        :except => SKIPPED_COLUMNS,
        :methods => [:_type]
      )

【问题讨论】：

标签： ruby-on-rails ruby activerecord include to-json

【解决方案1】：

为什么你有两次blog？

blog.to_json(
    :include => { :blog => {

我认为，第二个blog 不应该在那里。试试这个：

blog.to_json(
  :include => [
    {
      :comments => {
        :except => SKIPPED_COLUMNS,
        :methods => [:_type]
      }
    }, {
      :users => {
        :except => SKIPPED_COLUMNS,
        :methods => [:_type]
      }
    }
  ],
  :except => SKIPPED_COLUMNS,
  :methods => [:_type]
)

【讨论】：

这只是一个错字。它实际上存储在数据中