3
我看到一個案例,其中Action.where(:name => "fred").first_or_create
在RSpec下運行時生成不正確的SQL,但在控制檯中正確執行。我很困惑。這是爲什麼where()。first_or_create只在RSpec中生成不正確的SQL?
這是模型。底層actions
表有一個字段,一個字符串,命名爲name
:
# file: app/models/action.rb
class Action < ActiveRecord::Base
def self.internalize(name)
self.where(:name => name).first_or_create
end
end
這裏的RSpec的測試:
# 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
這裏的失敗:
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)>'
看來,當記錄存在,Action.where(:name => "fred").first_or_create
正在生成SQL
SELECT "actions".* FROM "actions" WHERE "name"."name" = 'fred' LIMIT 1
......這是錯誤的 - 它正在尋找名爲「名稱」的表。
奇怪的是,在控制檯中輸入完全相同的東西會正常運行。是的,我記得(這次)在運行我的RSpec測試之前輸入rake db:test:prepare
。我正在運行
Ruby version 1.9.3 (x86_64-darwin10.8.0)
Rails version 3.2.1
RSpec 2.9.0
這是怎麼回事?
這意味着,它的工作原理Rails的控制檯上的事實是幸運的巧合。 – 2012-03-25 02:51:05
@Mik:請解釋一下?據我所知,'Action.internalize(:name =>「fred」)'生成where子句'Action.where(:name =>「fred」)',否? [見http://guides.rubyonrails.org/active_record_querying.html#hash-conditions]。你在哪裏得到嵌套散列? – 2012-03-25 05:56:19
@Mik:OOHHHHH!是的,這是我的一個非常愚蠢的錯字。對Action.internalize(:name =>「fred」)的調用應該只是Action.internalize(「fred」)。你不知道我有多少次盯着那段代碼,完全錯過了它。 – 2012-03-25 06:50:41