Ransack,查找具有所有相关记录的记录

Question

我有一个配方模型,其中包含很多成分,每种成分都属于一个项目.在我的高级搜索表单中,我希望用户选择多种成分,让Ransack找到包含用户选择的所有成分的配方.

我尝试了以下搜索字段:

= f.collection_select(:ingredients_item_id_in, Item.all, :id, :name, {}, {multiple: true})

但从逻辑上讲,这会导致显示的所有配方都含有任何选定的成分.

由于一条记录不能包含多个item_id值,因此更改:ingredients_item_id_in为:ingredients_item_id_in_all不正确的查询结果.

有关在Ransack中创建此搜索参数的任何想法,还是应该为此创建子查询？

根据要求,我的控制器搜索方法:

  def search
    @q = Recipe.ransack(params[:q])
    @recipes = @q.result(distinct: true).include_related_models.published
  end

Answer 1

我最近在我的项目中遇到了类似的任务（Rails 4.2.4 / Ruby 2.3.1）。

庄园有很多舒适设施。我需要获得所有房产，其中包括所有选定的舒适设施。

这是我如何解决它的方法Ransack

就我而言，我有has_many :through关系。

房地产.rb

class Estate < ActiveRecord::Base
  has_many :estate_comforts
  has_many :comforts, through: :estate_comforts
end

舒适.rb

class Comfort < ActiveRecord::Base
  has_many :estate_comforts
  has_many :estates, through: :estate_comforts
end

庄园舒适.rb

class EstateComfort < ActiveRecord::Base
  belongs_to :estate
  belongs_to :comfort
end

对于复杂的查询，您需要通过 进行搜索post。为此，您必须像这样编辑路线。并将search动作添加到estates_controlle.rb. 欲了解更多信息，请阅读 Ransack wiki

路线.rb

...
resources :estates
  collection do
    match 'search' => 'estates#search', via: %i[get post], as: :search
  end
end

Estates_controller.rb

class EstatesController < ApplicationController
  ...

  def index
    @q = Estate.ransack(params[:q])

    @estates =
      if params[:q]&.has_key?(:estate_comforts_comfort_id_eq_any)
        # Store checked comforts
        session[:estate_comforts_comfort_id_eq_any] = params[:q][:estate_comforts_comfort_id_eq_any]

        comforts_count = params[:q][:estate_comforts_comfort_id_eq_any].count
        ids = @q.result.includes(:estate_comforts).group_by(&:id).select { |_, v| v.count == comforts_count}.keys
        Estate.where(id: ids)
      else
        @q.result(distinct: true)
      end
  end

  def search
    index
    render :index
  end
end

最后是模板部分......

庄园/index.haml

= search_form_for @q, url: search_estates_path, html: { method: :post } do |f|
  # here goes the form inputs

  # Polulate checkboxes with previously checked comforts 
  - Comfort.find_each do |comfort|
    # Was checked previously?
    - checked = comfort.id.to_s.in?(session[:estate_comforts_comfort_id_eq_any].to_a)
    %div  
      %input{ name: 'q[estate_comforts_comfort_id_eq_any][]',
              type: "checkbox",
              id: "checkbox#{comfort.id}",
              value: comfort.id,
              checked: checked }
        %label{for: "checkbox#{comfort.id}"}= comfort.name

将生成以下html

class Estate < ActiveRecord::Base
  has_many :estate_comforts
  has_many :comforts, through: :estate_comforts
end