ruby-on-rails - 尝试运行“rake db:populate”时，“main:Object 的未定义局部变量或方法‘n’”

Question

我正在阅读 Michael Hartl 的教程，但没有收到错误消息：

undefined local variable or method `n' for main:Object

当我跑步时bundle exec rake db:populate

sample_data.rake 文件

namespace :db do
  desc "Fill database with sample data"
  task populate: :environment do
    name  = Faker::Name.name
    email = "example-#{n+1}@railstutorial.org"
    password  = "password"
    User.create!(name: name,
                   email: email,
                   password: password,
                   password_confirmation: password)
  end
end

Answer 1

您在电子邮件旁边有 n 个内插字符串，它没有在任何地方定义。删除或定义它。

Answer 2

只需在脚本开头将n变量初始化为.0name

namespace :db do
  desc "Fill database with sample data"
  task populate: :environment do
    n = 0
    name  = Faker::Name.name
    email = "example-#{n+1}@railstutorial.org"
    password  = "password"
    User.create!(name: name,
                   email: email,
                   password: password,
                   password_confirmation: password)
  end
end

这段代码很可能是循环使用的。在这里，您实际上不需要n.