首先，在这里张贴一个菜鸟的位置，所以请告诉我，如果我的格式是关闭的或类似的东西，我会很乐意解决它：）
我一直在关注迈克尔·哈特尔的Rails教程，它很棒。我确定我的问题是由于我没有做正确的事情，但我无法在网上找到可以解决问题的任何内容。
我在第6章中创建了一个用户数据库。一切正常，直到我尝试user.save
仅供参考，以下是导致问题的步骤：
rails generate model User name:string email:string
然后：
bundle exec rake db:migrate
打开一个沙盒控制台：
rails console --sandbox
建立新用户
user = User.new(name: "Michael Hartl", email: "mhartl@example.com")
保存：
user.save
所有东西都给了我预期的输出，直到user.save给出了这个
IRB（主）：002：0＆GT; user.save （0.1ms）SAVEPOINT active_record_1 （0.1ms）ROLLBACK TO SAVEPOINT active_record_1 ArgumentError：参数数量错误（1表示0） 来自/Users/Jonathon/.rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activerecord-4.2.0.beta4/lib/active_record/connection_adap ters / abstract_adapter.rb：271：
initialize' from /Users/Jonathon/.rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activerecord-4.2.0.beta4/lib/active_record/connection_adap ters/abstract_adapter.rb:271:in新＆＃39; 来自/Users/Jonathon/.rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activerecord-4.2.0.beta4/lib/active_record/connection_adap ters / abstract_adapter.rb：271：在substitute_at' from /Users/Jonathon/.rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activerecord-4.2.0.beta4/lib/active_record/relation.rb:97: in块中的substitute_values＆＃39; 来自/Users/Jonathon/.rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activerecord-4.2.0.beta4/lib/active_record/relation.rb:96： 在each' from /Users/Jonathon/.rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activerecord-4.2.0.beta4/lib/active_record/relation.rb:96: ineach_with_index＆＃39; 来自/Users/Jonathon/.rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activerecord-4.2.0.beta4/lib/active_record/relation.rb:96： 在substitute_values' from /Users/Jonathon/.rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activerecord-4.2.0.beta4/lib/active_record/relation.rb:56: in插入＆＃39; 来自/Users/Jonathon/.rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activerecord-4.2.0.beta4/lib/active_record/persistence.rb: 521：在_create_record' from /Users/Jonathon/.rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activerecord-4.2.0.beta4/lib/active_record/counter_cache.r b:139:in_ create_record＆＃39; 来自/Users/Jonathon/.rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activerecord-4.2.0.beta4/lib/active_record/attribute_metho ds / dirty.rb：122：在_create_record＆＃39;中的_create_record' from /Users/Jonathon/.rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activerecord-4.2.0.beta4/lib/active_record/callbacks.rb:30 6:in块中 来自/Users/Jonathon/.rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activesupport-4.2.0.beta4/lib/active_support/callbacks.rb: 88：在call' from /Users/Jonathon/.rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activesupport-4.2.0.beta4/lib/active_support/callbacks.rb: 88:in_ run_callbacks＆＃39; 来自/Users/Jonathon/.rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activesupport-4.2.0.beta4/lib/active_support/callbacks.rb: 734：在_run_create_callbacks' from /Users/Jonathon/.rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activerecord-4.2.0.beta4/lib/active_record/callbacks.rb:30 6:in_ create_record＆＃39; ...... 22级...... 来自/Users/Jonathon/.rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/railties-4.2.0.beta4/lib/rails/commands/console.rb:9:in {{ 1}}控制台＆＃39; 来自/Users/Jonathon/.rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/railties-4.2.0.beta4/lib/rails/commands/commands_tasks.rb: 39：在s tart' from /Users/Jonathon/.rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/railties-4.2.0.beta4/lib/rails/commands/commands_tasks.rb: 68:in＆＃39; 来自/Users/Jonathon/.rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activesupport-4.2.0.beta4/lib/active_support/dependencies。 rb：252：在run_command!' from /Users/Jonathon/.rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/railties-4.2.0.beta4/lib/rails/commands.rb:17:in块中的require＆＃39; 来自/Users/Jonathon/.rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activesupport-4.2.0.beta4/lib/active_support/dependencies。 rb：237：require' from /Users/Jonathon/.rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activesupport-4.2.0.beta4/lib/active_support/dependencies. rb:252:in要求＆＃39; from / Users / Jonathon / Documents / Aptana Studio 3 Workspace / RoR / bin / rails：8：inload_dependency' from /Users/Jonathon/.rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activesupport-4.2.0.beta4/lib/active_support/dependencies. rb:252:inload＆＃39; 来自/Users/Jonathon/.rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activesupport-4.2.0.beta4/lib/active_support/dependencies。 rb：246：在<top (required)>' from /Users/Jonathon/.rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activesupport-4.2.0.beta4/lib/active_support/dependencies. rb:246:inload_dependency＆＃39; 来自/Users/Jonathon/.rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activesupport-4.2.0.beta4/lib/active_support/dependencies。 rb：246：block in load' from /Users/Jonathon/.rbenv/versions/2.1.3/lib/ruby/gems/2.1.0/gems/activesupport-4.2.0.beta4/lib/active_support/dependencies. rb:237:in要求＆＃39; 来自/Users/Jonathon/.rbenv/versions/2.1.3/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55:inload' from /Users/Jonathon/.rbenv/versions/2.1.3/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55:in＆＃39; irb（main）：003： 0 GT;
我已将我的user.rb文件放在此处：
require'
from -e:1:in
和我的create_users.rb文件也在这里
class User < ActiveRecord::Base
end
感谢并告诉我是否还有我需要提供的信息！
答案 0 :(得分：0)
感谢所有帮助人员！
Slothbear是对的，结果是我的数据库出了问题。克隆了教程git并解决了问题。
答案 1 :(得分：0)
我遇到了同样的问题。当我像你一样尝试ArgumentError时，我首先得到user.save。然后当我尝试rake db:drop然后rake db:migrate时，我也遇到了同样的错误。
我的案例是在bundle update之后，我发现这个arel gem版本出现了问题。它在Gemfile.lock上显示arel (6.0.0)，但是当我像之前一样尝试arel (6.0.0.beta2)时，它就有用了。
我不知道为什么。我找到了this discussion。现在我们对非beta Rails 4.2.0没有问题，如果我们不在示例应用程序上bundle update（正如作者所说），那么Hartl教程没有问题