在 rails 中进行联合搜索

Question

我正在 rails 项目中进行简单的联合搜索。我想要做的是根据用户在搜索框中输入的内容找到项目的描述。我最常遇到的错误是：

Mysql2::错误：'where clause' 中的未知列 'item.description'：SELECT item_instances。* FROM item_instances INNER JOIN items ON items.id = item_instances.item_id 其中 item.description = 'server'

search.html.erb 页面如下所示：

<p>
  Search results base on database field <span class='bold'><%= @columnType %></span> 
  with value: <span class='bold'><%= @search_value %> </span>
</p>

<p>Total Report Cost: <span class='bold'>$<%= @cost %><span></p>

<table class='reportTable'>
  <thead>
    <tr>
      <th class='reportTableHeaderCell'>Inv number</th>
      <th class='reportTableHeaderCell'>Description</th>
      <th class='reportTableHeaderCell'>Serial</th>
      <th class='reportTableHeaderCell'>PO number</th>
      <th class='reportTableHeaderCell'>PO date</th>
      <th class='reportTableHeaderCell'>Invoice</th>
      <th class='reportTableHeaderCell'>Date Out</th>
      <th class='reportTableHeaderCell'>Cost</th>
      <th class='reportTableHeaderCell'>Acro</th>
    </tr>
  </thead>

  <tbody>
    <% @item_instances.each do |item_instance| %>
      <tr class='searchTableRow'>
        <td class='reportTableCell'><%= link_to item_instance.inv_number, edit_item_instance_path(item_instance) %></td>
        <td class='reportTableCell'><%= item_instance.item.description %></td>
        <td class='reportTableCell'><%= item_instance.serial %></td>
        <td class='reportTableCell'><%= item_instance.po_number %></td>
        <td class='reportTableCell'><%= item_instance.po_date %></td>
        <td class='reportTableCell'><%= item_instance.invoice %></td>
        <td class='reportTableCell'><%= item_instance.date_out %></td>
        <td class='reportTableCell'><%= item_instance.cost %></td>
        <td class='reportTableCell'><%= item_instance.acro %></td>
      </tr>
    <% end %>
  </tbody>
</table>

item_instances.rb（型号）文件

class ItemInstance < ApplicationRecord
    validates :inv_number, :serial, :cost, presence: true
    belongs_to :item
    scope :in_order, ->{order(:description)}
    

    # Named Scopes 
    scope :search_for_records_by_date, ->(startDate, endDate) { where(date_out: startDate..endDate) }
    scope :search_for_records_by_column_and_value, ->(columnName, value) { where("#{columnName}": "#{value}") }
    
    #I know something may be wrong in here. 
    scope :search_for_records_by_column_and_value_item_table, ->(columnName, value) { where(item: "#{columnName}": "#{value}") }
    
end

物品型号：

class Item < ApplicationRecord
    validates :description, :cost, :list_price, presence: true
    has_many :item_instances, dependent: :delete_all
    
    scope :in_order, ->{order(:description)}
    scope :search_for_active_items, ->(active) { where(active: active) }
    scope :search_for_records_by_column_and_value_on_items, ->(columnName, value) { where("#{columnName}": "#{value}") }
end

item_instances 控制器：

class ItemInstancesController < ApplicationController

    def search 
     # Getting the params from what the user submitted 
     @columnType = params[:columnType]
     @search_value = params[:search_value]


     if @columnType == 'description'
      # SIMPLE THINGS I've TRIED:
      # @item_instances = ItemInstance.joins(:item).where(item: {description: "server"})
      #@item_instances = ItemInstance.joins(:items)
      #I TRIED THIS JUST TO SEE IF I COULD GET ANYTHING
      @item_instances = ItemInstance.joins(:item).where(:item => {description: "server"})

      #@item_instances = ItemInstance.joins(:item).search_for_records_by_column_and_value_item_table(@columnType, @search_value)
    end

    respond_to do |format| 
      format.html { render :search }
    end

  end 

end

路由文件：

Rails.application.routes.draw do
  resources :item_instances
  get '/report', to: 'item_instances#report'
  get '/search', to: 'item_instances#search'

  resources :items
  get '/active', to: 'items#active'

  # Route to the home page 
  root 'item_instances#home'

end

schema.rb 文件：

ActiveRecord::Schema.define(version: 2020_08_17_190727) do

  create_table "item_instances", options: "ENGINE=InnoDB DEFAULT CHARSET=latin1", force: :cascade do |t|
    t.integer "inv_number"
    t.string "serial"
    t.integer "po_number"
    t.date "po_date"
    t.date "invoice"
    t.date "date_out"
    t.decimal "cost", precision: 8, scale: 2
    t.string "acro"
    t.datetime "created_at", null: false
    t.datetime "updated_at", null: false
    t.bigint "item_id"
    t.index ["item_id"], name: "fk_rails_6ea33fd9d0"
  end

  create_table "items", options: "ENGINE=InnoDB DEFAULT CHARSET=latin1", force: :cascade do |t|
    t.string "description"
    t.decimal "cost", precision: 8, scale: 2
    t.decimal "list_price", precision: 8, scale: 2
    t.datetime "created_at", null: false
    t.datetime "updated_at", null: false
    t.boolean "active"
  end

  add_foreign_key "item_instances", "items"
end

如果还需要什么，请告诉我。我浏览了多篇文章和 Whosebug 帖子，但没有成功。任何可以提供帮助的东西都将不胜感激。

Answer 1

在您的 item_instances_controller.rb 中，将 item 替换为 where 条件下的项目。在 where 条件下，您必须指定完整的 table 名称以进行比较。

class ItemInstancesController < ApplicationController

    def search 

    #yourcode
      @item_instances = ItemInstance.joins(:item).where(:items => {description: "server"})

    #yourcode

  end 

end

在 rails 中进行联合搜索

Doing a joined search in rails

search

join

ruby-on-rails-5