ActiveRecord属性用户总和，投票查询轨道？

Question

我想在我的视图中显示与“rateable_id：3”相关的所有属性。 我是新来的查询dbs并在视图中显示结果。另外，我想在视图中显示“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

您可能希望在控制器的show方法中执行此操作，因为这会调用特定的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show视图中，您可以使用count获取针对唯一Rate值返回的rater_id条记录总数：

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

Answer 2

总和：

您可以使用两个查询

@rankings_by_raters = Rate.group(:rater_id).count
@rankings_by_rateable = Rate.group(:rateable_id).count

这将为您提供两个哈希值，其中rater和rateable的ID为关键字，相关值为值。

对于节目：

@rankings_for_rate = Rate.where(rater_id: params[:rater_id])