Question

我正在阅读Michael Hartl的教程，我无法得到错误：

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

当我运行bundle exec rake db:populate

时

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内插字符串，并且未在任何地方定义。删除或定义它。

Answer 2

只需在脚本开头n之前将0变量初始化为name。

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

这段代码可能用在一个循环中。在这里，您实际上不需要n。

当尝试运行“rake db：populate”时，“未定义的局部变量或方法`n'用于main：Object”

2 个答案: