用户有3种语言

Question

我有两个模型：用户和语言模型。一个用户可以使用三种不同的语言。我想向用户展示一种语言。

class User < ActiveRecord::Base
  # Include default devise modules. Others available are:
  # :confirmable, :lockable, :timeoutable and :omniauthable
  devise :database_authenticatable, :registerable,
         :recoverable, :rememberable, :trackable, :validatable,
         :omniauthable, omniauth_providers: [:facebook]
  has_many :messages, dependent: :destroy
  has_many :pictures, dependent: :destroy
  has_many :posts, dependent: :destroy
  has_many :comments, dependent: :destroy
  belongs_to :first_language, class_name: 'Language'
  belongs_to :second_language, class_name: 'Language'
  belongs_to :third_language, class_name: 'Language'
 end

class Language < ActiveRecord::Base
  has_many :users, foreign_key: "first_language_id"
  # How to do the same with second and third language ?
end

对于语言控制器，我不知道如何找到说（第一，第二或第三语言）语言的用户！

class LanguagesController < ApplicationController
  before_action :authenticate_user!
  before_action :find_language, only: :show

  def show
    @users = @language.users
    # How to select the users who speak first, second or third language ? 
  end

  private
    def find_language
      @language = Language.find(params[:id])
    end
end

用户架构：

  create_table "users", force: :cascade do |t|
    t.string   "email",                  default: "", null: false
    t.string   "encrypted_password",     default: "", null: false
    t.string   "reset_password_token"
    t.datetime "reset_password_sent_at"
    t.datetime "remember_created_at"
    t.integer  "sign_in_count",          default: 0,  null: false
    t.datetime "current_sign_in_at"
    t.datetime "last_sign_in_at"
    t.inet     "current_sign_in_ip"
    t.inet     "last_sign_in_ip"
    t.datetime "created_at",                          null: false
    t.datetime "updated_at",                          null: false
    t.string   "provider"
    t.string   "uid"
    t.string   "picture"
    t.string   "first_name"
    t.string   "last_name"
    t.string   "token"
    t.datetime "token_expiry"
    t.integer  "first_language_id"
    t.integer  "second_language_id"
    t.integer  "third_language_id"
    t.string   "description"
  end

语言架构：

  create_table "languages", force: :cascade do |t|
    t.string   "title"
    t.datetime "created_at", null: false
    t.datetime "updated_at", null: false
  end

Answer 1

class User < ActiveRecord::Base
    belongs_to :first_language, class_name: 'Language'
  belongs_to :second_language, class_name: 'Language'
  belongs_to :third_language, class_name: 'Language'
end

class Language < ActiveRecord::Base
    has_many :users
end

您可以通过

访问特定语言的用户

@language.users