Rails 4 - 销毁不工作

Question

我正在尝试在 Rails 4.

中制作一个应用程序

我有一个行业模型。它与我的个人资料模型和组织模型中的每一个都有并且属于许多关联。

协会是：

industry.rb

has_and_belongs_to_many :organisations
  has_and_belongs_to_many :profiles

organisation.rb

has_and_belongs_to_many :industries

profile.rb

has_and_belongs_to_many :industries
  has_and_belongs_to_many :projects

我的架构有：

create_table "industries", force: :cascade do |t|
    t.string   "sector"
    t.string   "icon"
    t.datetime "created_at", null: false
    t.datetime "updated_at", null: false
  end

  create_table "industries_profiles", id: false, force: :cascade do |t|
    t.integer "industry_id"
    t.integer "profile_id"
  end

  add_index "industries_profiles", ["industry_id"], name: "index_industries_profiles_on_industry_id", using: :btree
  add_index "industries_profiles", ["profile_id"], name: "index_industries_profiles_on_profile_id", using: :btree

我有一个行业索引，它是我在我的开发环境中创建的。我现在正在尝试删除一个。

当我在索引中单击删除 link 时，出现此错误：

ActiveRecord::StatementInvalid in IndustriesController#destroy
PG::UndefinedTable: ERROR: relation "industries_organisations" does  
not exist LINE 5: WHERE a.attrelid = '"industries_organisations... ^ :   
SELECT a.attname, format_type(a.atttypid, a.atttypmod), pg_get_expr(d.adbin, d.adrelid),  
a.attnotnull, a.atttypid, a.atttypmod FROM pg_attribute a LEFT JOIN pg_attrdef  
d ON a.attrelid = d.adrelid AND a.attnum = d.adnum WHERE a.attrelid =  
'"industries_organisations"'::regclass AND a.attnum > 0 AND NOT a.attisdropped ORDER BY a.attnum

如何删除记录？

行业控制器有：

class IndustriesController < ApplicationController
  before_action :set_industry, only: [:show, :edit, :update, :destroy]

  # GET /industries
  # GET /industries.json
  def index
    #@industries = Industry.all
    @industries = Industry.alphabetically
  end

  # GET /industries/1
  # GET /industries/1.json
  def show
  end

  # GET /industries/new
  def new
    @industry = Industry.new
  end

  # GET /industries/1/edit
  def edit
  end

  # POST /industries
  # POST /industries.json
  def create
    @industry = Industry.new(industry_params)

    respond_to do |format|
      if @industry.save
        format.html { redirect_to @industry, notice: 'Industry was successfully created.' }
        format.json { render :show, status: :created, location: @industry }
      else
        format.html { render :new }
        format.json { render json: @industry.errors, status: :unprocessable_entity }
      end
    end
  end

  # PATCH/PUT /industries/1
  # PATCH/PUT /industries/1.json
  def update
    respond_to do |format|
      if @industry.update(industry_params)
        format.html { redirect_to @industry, notice: 'Industry was successfully updated.' }
        format.json { render :show, status: :ok, location: @industry }
      else
        format.html { render :edit }
        format.json { render json: @industry.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /industries/1
  # DELETE /industries/1.json
  def destroy
    @industry.destroy
    respond_to do |format|
      format.html { redirect_to industries_url, notice: 'Industry was successfully destroyed.' }
      format.json { head :no_content }
    end
  end

  private
    # Use callbacks to share common setup or constraints between actions.
    def set_industry
      @industry = Industry.find(params[:id])
    end

    # Never trust parameters from the scary internet, only allow the white list through.
    def industry_params
      params.require(:industry).permit(:id, :sector, :icon)
    end
end

Answer 1

如果您要建立 many to many 关系，则需要 table industries_organisations 关系。有关详细信息，请阅读此处的文档：

Many to many association

Rails 4 - 销毁不工作

Rails 4 - Destroy not working

postgresql

ruby-on-rails

associations