使用Faker的用户和主题种子数据的问题

Question

我是编程新手，并且一直在尝试使用Faker为一个简单的书签应用程序制作一些种子数据。主题属于用户，书签属于主题，因此我尝试使用具有user_id的主题制作种子数据。最初，我只是放了user.sample，但是我需要拥有该主题的用户的user_id，并且书签需要它所属主题的topic_id。您可以在下面看到我的一项努力。你是怎么做的？这是我的种子数据：

require 'faker'

    #create users
    10.times do 
      user = User.new(
        name: Faker::Name.name,
        email: Faker::Internet.email,
        password: 'helloworld'
      )
      user.save!  
    end
    users=User.all

    # create bookmarks
    30.times do 
        Bookmark.create(
        topic_id: topic.sample,
        url: Faker::Internet.url
        )
      end
      bookmarks = Bookmark.all

    # create topics
    10.times do
      Topic.create(
        name: Faker::Name.name,
        user_id: user.sample
      )
    end
    topics= Topic.all

    #create admin
    admin = User.new(
      name: 'admin',
      email: 'admin@example.com',
      password: 'helloworld'
    )
    admin.save

    puts 'Seed Finished'
    puts "#{users.count} users created"
    puts "#{topics.count} topics created"
    puts "#{bookmarks.count} bookmarks created"

这是我的架构：

ActiveRecord::Schema.define(version: 20150118002825) do

  create_table "bookmarks", force: true do |t|
    t.string   "url"
    t.integer  "topic_id"
    t.datetime "created_at"
    t.datetime "updated_at"
  end

  create_table "likes", force: true do |t|
    t.integer  "user_id"
    t.integer  "bookmark_id"
    t.datetime "created_at"
    t.datetime "updated_at"
  end

  create_table "topics", force: true do |t|
    t.string   "name"
    t.integer  "user_id"
    t.datetime "created_at"
    t.datetime "updated_at"
  end

  create_table "users", force: true do |t|
    t.string   "name"
    t.string   "email"
    t.string   "password_digest"
    t.datetime "created_at"
    t.datetime "updated_at"
  end

end

以下是我的模特：

class Topic < ActiveRecord::Base
  belongs_to :user
  has_many :bookmarks

end
class User < ActiveRecord::Base
  has_secure_password

  has_many :topics

end
class Bookmark < ActiveRecord::Base

  belongs_to :topics
  has_many :likes

end