ruby-on-rails - 为什么where()。first_or_create仅在RSpec中生成不正确的SQL？

Question

我看到一种情况，其中Action.where(:name => "fred").first_or_create在RSpec下运行时生成不正确的SQL，但在控制台中正确执行。我很困惑。

这是模型。基础actions表具有一个字段，一个名为name的字符串：

# file: app/models/action.rb
class Action < ActiveRecord::Base
  def self.internalize(name)
    self.where(:name => name).first_or_create
  end
end

这是rspec测试：

# file: spec/models/action_spec.rb
require 'spec_helper'
describe Action do
  describe 'intern' do
    it 'should create a new name' do  # works
      lambda { Action.internalize("fred") }.should change { Action.count }.by(1)
    end
    it 'should not create duplicate names' do  # fails
      Action.internalize(:name => "fred")
      lambda { Action.internalize("fred") }.should_not change { Action.count }
    end
  end
end

这是失败的地方：

1) Action intern should not create duplicate names
   Failure/Error: Action.internalize(:name => "fred")
   ActiveRecord::StatementInvalid:
     PG::Error: ERROR:  missing FROM-clause entry for table "name"
     LINE 1: SELECT  "actions".* FROM "actions"  WHERE "name"."name" = 'f...
     : SELECT  "actions".* FROM "actions"  WHERE "name"."name" = 'fred' LIMIT 1
   # ./app/models/action.rb:4:in `internalize'
   # ./spec/models/action_spec.rb:12:in `block (3 levels) in <top (required)>'

似乎当记录存在时，Action.where(:name => "fred").first_or_create正在生成SQL

SELECT "actions".* FROM "actions" WHERE "name"."name" = 'fred' LIMIT 1

...这是错误的-它正在寻找一个名为“ name”的表。

奇怪的是，在控制台中键入完全相同的内容会正常执行。是的，我记得（这次）在运行RSpec测试之前键入rake db:test:prepare。我在跑

Ruby version              1.9.3 (x86_64-darwin10.8.0)
Rails version             3.2.1
RSpec                     2.9.0

这里到底发生了什么？

Answer 1

Action.internalize(:name => "fred")正在生成where子句：

where(:name => {:name => "fred"})

这意味着，您有一个关联的表name，该表的列name的值为fred