bundle exec rake db:populate - activerecord::recordinvalid:validation failed:email has been taken答案

【问题标题】：bundle exec rake db:populate - activerecord::recordinvalid:validation failed:email has already been takenbundle exec rake db:populate - activerecord::recordinvalid:validation failed:email has been taken
【发布时间】：2014-07-03 08:47:09
【问题描述】：

我目前正在阅读 michael hartl 教程的第 10 章，当我尝试执行 bundle exec rake db:populate 时出现问题。

附上错误信息：

rake aborted!                                                                                                                        
ActiveRecord::RecordInvalid: Validation failed: Email has already been taken                                                         
/home/action/.gem/ruby/2.0.0/gems/activerecord-4.1.1/lib/active_record/validations.rb:57:in `save!'                                  
/home/action/.gem/ruby/2.0.0/gems/activerecord-4.1.1/lib/active_record/attribute_methods/dirty.rb:29:in `save!'                      
/home/action/.gem/ruby/2.0.0/gems/activerecord-4.1.1/lib/active_record/transactions.rb:273:in `block in save!'                       
/home/action/.gem/ruby/2.0.0/gems/activerecord-4.1.1/lib/active_record/transactions.rb:329:in `block in with_transaction_returning_st
atus'                                                                                                                                
/home/action/.gem/ruby/2.0.0/gems/activerecord-4.1.1/lib/active_record/connection_adapters/abstract/database_statements.rb:211:in `bl
ock in transaction'                                                                                                                  
/home/action/.gem/ruby/2.0.0/gems/activerecord-4.1.1/lib/active_record/connection_adapters/abstract/database_statements.rb:219:in `wi
thin_new_transaction'                                                                                                                
/home/action/.gem/ruby/2.0.0/gems/activerecord-4.1.1/lib/active_record/connection_adapters/abstract/database_statements.rb:211:in `tr
ansaction'                                                                                                                           
/home/action/.gem/ruby/2.0.0/gems/activerecord-4.1.1/lib/active_record/transactions.rb:208:in `transaction'                          
/home/action/.gem/ruby/2.0.0/gems/activerecord-4.1.1/lib/active_record/transactions.rb:326:in `with_transaction_returning_status'    
/home/action/.gem/ruby/2.0.0/gems/activerecord-4.1.1/lib/active_record/transactions.rb:273:in `save!'                                
/home/action/.gem/ruby/2.0.0/gems/activerecord-4.1.1/lib/active_record/validations.rb:41:in `create!'                                
/home/action/workspace/app3/lib/tasks/sample_data.rake:4:in `block (2 levels) in <top (required)>'                                   
Tasks: TOP => db:populate                                                                                                            
(See full trace by running task with --trace)

附上sample_data.rake文件：

namespace :db do
  desc "Fill database with sample data"
  task populate: :environment do
    admin = User.create!(name: "Example User",
                         email: "example@railstutorial.org",
                         password: "foobar",
                         password_confirmation: "foobar",
                         admin: true)
    User.create!(name: "Example User",
                 email: "example@railstutorial.org",
                 password: "foobar",
                 password_confirmation: "foobar")
    99.times do |n|
      name  = Faker::Name.name
      email = "example-#{n+1}@railstutorial.org"
      password  = "password"
      User.create!(name: name,
                   email: email,
                   password: password,
                   password_confirmation: password)
      users = User.all(limit: 6)
      50.times do
        content = Faker::Lorem.sentence(5)
        users.each { |user| user.microposts.create!(content: content) }
      end
    end
  end
end

【问题讨论】：

您正在尝试使用电子邮件 example@railstutorial.org 创建两个用户，并对用户模型进行验证。只需从 rake 文件中删除其中一个即可。
@Baloo 通过 rake 文件你的意思是 sample_data.rake 吗？还是 Rakefile？

标签： ruby-on-rails ruby activerecord railstutorial.org

【解决方案1】：

admin = User.create!(name: "Example User",
  email: "example@railstutorial.org",
  password: "foobar",
  password_confirmation: "foobar",
  admin: true)

User.create!(name: "Example User",
  email: "example@railstutorial.org", # This email is used to create admin above.
                                      # Use another email here
  password: "foobar",
  password_confirmation: "foobar")

错误来自这一行

users = User.all(limit: 6)

活动记录方法all 不接受任何参数。改成

users = User.limit(6)

【讨论】：

您好，我这样做了，但出现参数错误：参数数量错误（1 代表 0）
从哪一行开始，那一行的代码是什么。错误消息的意思是，您正在调用一个带有 1 个参数的方法，但它并不期望任何参数。
这是错误！耙中止！ ArgumentError：参数数量错误（1 代表 0）/home/action/.gem/ruby/2.0.0/gems/activerecord-4.1.1/lib/active_record/scoping/named.rb:24:in all' /home/action/workspace/app3/lib/tasks/sample_data.rake:22:in block （3 个级别）在 ' /action/workspace/app3/lib/tasks/sample_data.rake:14:in `times'

【解决方案2】：

很可能，您已经解决了这个问题，我也遇到了这个问题，并通过在模型文件中添加attr_accessible :content 或其他attr_accessible 来解决它。我希望这对其他人有帮助。

【讨论】：