ruby-on-rails – Rails 3：为什么Rails在运行简单测试时会尝试

ruby -I test test/unit/job_test.rb

从我的应用程序根目录,我得到：

Loaded suite test/unit/job_test
Started
E
Finished in 2.046875 seconds.

1) Error:
   test_My_First_Test(JobTest):
   ActiveRecord::RecordNotUnique: Mysql2::Error: Duplicate entry '' 
   for key 'name':
   INSERT INTO `ac_buyers` (`created_at`,`updated_at`,`id`) VALUES 
   ('2011-03-10 06:04:06','2011-03-10 06:04:06',298486374)

这里发生了什么 ？

为什么Rails尝试将值插入数据库？

这是test / unit / job_test.rb：

require 'test_helper'
class JobTest < ActiveSupport::TestCase
  test "My First Test" do
    assert false
  end
end