mysql - ActiveRecord属性总和用户，投票查询rails？

Question

我想在我的 View 中显示与“rateable_id: 3”相关的所有属性。我是查询数据库并在 View 中显示结果的新手。另外，我想在 View 中显示“rater_id:”(有多少用户投票)的总和，例如“rateable_id:3”。

这是在我的ranking_controller.rb中:

class RankingController < ApplicationController
  def index
    @rankings = Rate.find(:all)
  end
end

这是我的表中的费率:

- !ruby/object:Rate
  attributes:
    id: 11
    rater_id: 1
    rateable_id: 3
    rateable_type: Bboy
    stars: 5.0
    dimension: foundation
    created_at: 2014-02-25 09:33:23.000000000 Z
    updated_at: 2014-02-25 09:33:23.000000000 Z
- !ruby/object:Rate
  attributes:
    id: 12
    rater_id: 1
    rateable_id: 3
    rateable_type: Bboy
    stars: 5.0
    dimension: originality
    created_at: 2014-02-25 09:33:24.000000000 Z
    updated_at: 2014-02-25 09:33:24.000000000 Z
- !ruby/object:Rate
  attributes:
    id: 13
    rater_id: 1
    rateable_id: 3
    rateable_type: Bboy
    stars: 5.0
    dimension: dynamics
    created_at: 2014-02-25 09:33:25.000000000 Z
    updated_at: 2014-02-25 09:33:25.000000000 Z
- !ruby/object:Rate
  attributes:
    id: 14
    rater_id: 1
    rateable_id: 3
    rateable_type: Bboy
    stars: 5.0
    dimension: execution
    created_at: 2014-02-25 09:33:26.000000000 Z
    updated_at: 2014-02-25 09:33:26.000000000 Z
- !ruby/object:Rate
  attributes:
    id: 15
    rater_id: 1
    rateable_id: 3
    rateable_type: Bboy
    stars: 5.0
    dimension: battle
    created_at: 2014-02-25 09:33:27.000000000 Z
    updated_at: 2014-02-25 09:33:27.000000000 Z
- !ruby/object:Rate
  attributes:
    id: 16
    rater_id: 1
    rateable_id: 5
    rateable_type: Bboy
    stars: 5.0
    dimension: foundation
    created_at: 2014-02-25 09:36:30.000000000 Z
    updated_at: 2014-02-25 09:36:30.000000000 Z
- !ruby/object:Rate
  attributes:
    id: 17
    rater_id: 1
    rateable_id: 5
    rateable_type: Bboy
    stars: 5.0
    dimension: originality
    created_at: 2014-02-25 09:36:31.000000000 Z
    updated_at: 2014-02-25 09:36:31.000000000 Z
- !ruby/object:Rate
  attributes:
    id: 18
    rater_id: 1
    rateable_id: 5
    rateable_type: Bboy
    stars: 5.0
    dimension: dynamics
    created_at: 2014-02-25 09:36:31.000000000 Z
    updated_at: 2014-02-25 09:36:31.000000000 Z
- !ruby/object:Rate
  attributes:
    id: 19
    rater_id: 1
    rateable_id: 5
    rateable_type: Bboy
    stars: 5.0
    dimension: battle
    created_at: 2014-02-25 09:36:32.000000000 Z
    updated_at: 2014-02-25 09:36:32.000000000 Z
- !ruby/object:Rate
  attributes:
    id: 25
    rater_id: 8
    rateable_id: 3
    rateable_type: Bboy
    stars: 1.0
    dimension: foundation
    created_at: 2014-03-04 14:06:46.000000000 Z
    updated_at: 2014-03-04 14:06:46.000000000 Z
- !ruby/object:Rate
  attributes:
    id: 26
    rater_id: 8
    rateable_id: 3
    rateable_type: Bboy
    stars: 1.0
    dimension: originality
    created_at: 2014-03-04 14:06:49.000000000 Z
    updated_at: 2014-03-04 14:06:49.000000000 Z
- !ruby/object:Rate
  attributes:
    id: 27
    rater_id: 8
    rateable_id: 3
    rateable_type: Bboy
    stars: 1.0
    dimension: dynamics
    created_at: 2014-03-04 14:06:51.000000000 Z
    updated_at: 2014-03-04 14:06:51.000000000 Z
- !ruby/object:Rate
  attributes:
    id: 28
    rater_id: 8
    rateable_id: 3
    rateable_type: Bboy
    stars: 1.0
    dimension: execution
    created_at: 2014-03-04 14:06:53.000000000 Z
    updated_at: 2014-03-04 14:06:53.000000000 Z
- !ruby/object:Rate
  attributes:
    id: 29
    rater_id: 8
    rateable_id: 3
    rateable_type: Bboy
    stars: 1.0
    dimension: battle
    created_at: 2014-03-04 14:06:54.000000000 Z
    updated_at: 2014-03-04 14:06:54.000000000 Z

Answer 1

您可能希望在 show 中执行此操作 Controller 中的方法，因为它将调用特定的 Ranking :

class RankingController < ApplicationController
  def index
    @rankings = Rate.find(:all)
  end

  def show
    @ranking = Rate.where(:rateable_id => params[:id])
  end
end

然后，在您的 show 中查看，您可以使用 count得到Rate的总数针对唯一 rater_id 返回的记录值:

@ranking.map(&:rater_id).uniq.count