thanatos (十六薙夜血)

Ruby 中 *0.1 和 /10 结果不一样？

thanatos — Fri, 14 Aug 2015 09:31:54 +0800

对于一个浮点型变量执行*0.1 和/10 为啥结果不同？比如 133.3 * 0.1 = 13.33000000000002 而 133.3/10= 13.33

谢谢！

数据库约束了 null false 后，做空值 test 会报 error

thanatos — Wed, 29 Jul 2015 17:47:50 +0800

做 model 的时候，在数据库层约束了 null 是 false，然后又在 model 本身加上了 validates presence: true。现在写 test，当尝试为其赋空值时，期望得到这个 record 没有添加成功，不想 test 直接给了 error，说 ActiveRecord::RecordInvalid: Validation failed: Assetnum（就是那个不能为空的字段）can't be blank。请问这样的测试应该怎么写？谢谢！贴代码：先建表，

create_table "hardwares", force: :cascade do |t|
    t.string   "AssetNum",        null: false
  #此处省略若干其他字段
    t.datetime "created_at",      null: false
    t.datetime "updated_at",      null: false
  end

然后做 model

class Hardware < ActiveRecord::Base
  validates :AssetNum, presence: true
end

create 动作是酱紫的

class HardwaresController < ApplicationController
  def new
    @hardware = Hardware.new
  end

  def create
    @hardware = Hardware.new(hardware_params)
    @hardware.save!
    redirect_to @hardware
  end
  private
    def hardware_params
      params.require(:hardware).permit(:AssetNum, :CPU, :Disk1Size, :Disk1Num,
                                       :Disk2Size, :Disk2Num, :Disk3Size,
                                       :Disk3Num, :Mem1Size, :Mem1Num, :Mem2Size,
                                       :Mem2Num, :BuyingTime, :DeployingTime,
                                       :Position, :ServerType, :ServerModel,
                                       :ServiceNum, :QuickServiceNum )
    end
end

程序到这里都 OK，可以正常的创建，于是我做了一个 test 来检测提交空值的 AssetNum 会不会创建这个记录，如下

class CreateHardwareTest < ActionDispatch::IntegrationTest

  def setup
    @h1 = hardwares(:h1)
  end

test "create hardware with invalid information" do

    assert_no_difference 'Hardware.count' do
      post hardwares_path, hardware: {
                             AssetNum: "" ,
                             CPU: @h1.CPU ,
                             Disk1Size: @h1.Disk1Size ,
                             Disk1Num: @h1.Disk1Num ,
                             Mem1Size: @h1.Mem1Size ,
                             Mem1Num:  @h1.Mem1Num ,
                             BuyingTime: @h1.BuyingTime ,
                             DeployingTime: @h1.DeployingTime ,
                             Position: @h1.Position ,
                             ServerType: @h1.ServerType ,
                             ServerModel: @h1.ServerModel ,
                             ServiceNum: @h1.ServiceNum ,
                             QuickServiceNum: @h1.QuickServiceNum
                         }
    end
  end
end

理论上来说 OK 的，但是跑测试的结果却是：

ERROR["test_create_hardware_with_invalid_information", CreateHardwareTest, 2015-07-29 08:39:36 +0800]
 test_create_hardware_with_invalid_information#CreateHardwareTest (1438130376.94s)
ActiveRecord::RecordInvalid:         ActiveRecord::RecordInvalid: Validation failed: Assetnum can't be blank
            app/controllers/hardwares_controller.rb:13:in `create'
            test/integration/create_hardware_test.rb:39:in `block (2 levels) in <class:CreateHardwareTest>'
            test/integration/create_hardware_test.rb:38:in `block in <class:CreateHardwareTest>'

  2/2: [=============================] 100% Time: 00:00:01, Time: 00:00:01

Finished in 1.07189s

求怎么破？谢谢！

懒人想找个能通过 “.” 自动带出方法的 IDE……

thanatos — Wed, 29 Jul 2015 10:09:26 +0800

各位社区的大大们好！我在 Linux 下学习 rails，开发过程中重复的手敲实在是受够了…… 我看过咱们关于开发环境的介绍：https://ruby-china.org/wiki/tools 但是我真的想用个少手工劳动的 IDE，我现在在用 aptana3，但是这个环境经常性的无法带出方法或属性，和普通文本编辑器差不多。跪求一个懒人用的 IDE 环境，非常感谢！

before_save 时修改 record 的 boolean 类型属性，导致 save! 失败

thanatos — Wed, 22 Jul 2015 12:25:18 +0800

在保存一个 record 的时候，我做了一个 before_save，对 record 进行判断并修改它的一个属性值。坑爹的是这个属性值是 boolean，如果方法返回 true 还好，record 可以保存，但是如果返回 false，属性值是赋上了 false，方法也返回 false，同时这个 false 会影响 before_save，导致 save！失败。没办法，我只能在 before_save 调用的方法中最后返回一句话，以保证永远都是 true，但是这样做感觉挺 sb 的，不知道正确的做法是啥样的？感谢？

class Host < ActiveRecord::Base
  before_save :idle?
  validates :HostName, presence: true

  def idle?
    if ( self.Adapter1IP.empty? && self.Adapter2IP.empty? && self.Adapter3IP.empty? && self.Adapter4IP.empty? && self.Adapter5IP.empty? )
      self.Idle = true
    else
      self.Idle = false
    end
    "shit!"
  end
end

[已解决] 保存前通过回调来更改属性，但是无法将属性值保存下来？

thanatos — Tue, 21 Jul 2015 10:07:55 +0800

保存前通过回调来更改属性，但是无法将属性值保存下来？创建了一个硬件资产 model，每个 record 都有 5 个网卡，所以对应的有 5 个属性值，在保存前我想判断其网卡空闲情况，如果所有网卡都是空值，就标注服务器为空闲：Idle=true

class Hardware < ActiveRecord::Base
  attr_accessor :Idle, :Adapter1IP, :Adapter2IP, :Adapter3IP, :Adapter4IP, :Adapter5IP
  before_save :idle?

def idle?
    if ( self.Adapter1IP.empty? && self.Adapter2IP.empty? || self.Adapter3IP.empty? || self.Adapter4IP.empty? || self.Adapter5IP.empty? )
      self.Idle = true
      #debugger
    else
      self.Idle = false
    end
  end
end

控制器是这样的

class HardwaresController < ApplicationController

  def show
    @hardware = Hardware.find(params[:id])
  end

  def new
  end

  def create
#   render plain: params[:hardware].inspect
    @hardware = Hardware.new(hardware_params)
    @hardware.Adapter1IP=''
    @hardware.Adapter2IP=''
    @hardware.Adapter3IP=''
    @hardware.Adapter4IP=''
    @hardware.Adapter5IP=''
    @hardware.save!

    redirect_to @hardware
  end

  private
    def hardware_params
         params.require(:hardware).permit!
    end
end

于是问题来了，我创建一个新的 record，可以正常保存，但是保存后显示其 idle 居然是 nil，像这样：显示资产： #

但是我在 idle？方法中在结尾加了 debugger，显示 self.Idle=true，在 create 方法中，在@hardware.save! 后 debugger，@hardware.Idle也显示为 true，为啥 redirect_to @hardware的时候，页面显示的 Idle 却是 nil 呢？哪有问题？谢谢！

又试了一下，我甚至在 create 中直接写上@hardware.Idle=true，显示出来的属性还是 nil，疯了啊！

[已解决] 想做一个保存前的检查，导致 save 失败，求指点，谢谢！

thanatos — Fri, 17 Jul 2015 19:59:12 +0800

创建了一个 model，对应我现有的硬件资产，如下

create_table "hardwares", force: :cascade do |t|
    t.string   "AssetNum",        null: false
    t.integer  "CPU",             null: false
    t.integer  "Disk",            null: false
    t.integer  "Mem",             null: false
    t.date     "BuyingTime",      null: false
    t.date     "DeployingTime",   null: false
    t.string   "Adapter1IP"
    t.string   "Adapter2IP"
    t.string   "Adapter3IP"
    t.string   "Adapter4IP"
    t.string   "Adapter5IP"
    t.string   "Position",        null: false
    t.string   "ServerType",      null: false
    t.string   "ServerModel",     null: false
    t.boolean  "PCorNot",         null: false
    t.string   "ServiceNum"
    t.string   "QuickServiceNum"
    t.boolean  "Idle"
    t.datetime "created_at",      null: false
    t.datetime "updated_at",      null: false
  end

然后做了个 controller 和对应的新建表单，用来保存数据

class HardwaresController < ApplicationController

  def show
    @hardware = Hardware.find(params[:id])
  end

  def new
  end

  def create
#   render plain: params[:hardware].inspect
    @hardware = Hardware.new(hardware_params)
    @hardware.Adapter1IP=''
    @hardware.Adapter2IP=''
    @hardware.Adapter3IP=''
    @hardware.Adapter4IP=''
    @hardware.Adapter5IP=''
    @hardware.save!
    redirect_to @hardware
  end

  private
    def hardware_params
      params.require(:hardware).permit(:AssetNum, :CPU, :Disk,:Mem,:BuyingTime,:DeployingTime,:Position,:ServerType,:ServerModel,:PCorNot, :ServiceNum, :QuickServiceNum, :Idle)
    end
end

我有一个美好的想法：无论在新建还是以后修改 hardware 记录的时候，保存前都检查一下五块网卡是不是都分配了 IP 地址，如果都没有，那就在这条记录的 Idle 上标注它是空闲，于是有了下面的代码：

class Hardware < ActiveRecord::Base
  attr_accessor :Idle, :Adapter1IP, :Adapter2IP, :Adapter3IP, :Adapter4IP, :Adapter5IP
  before_save { self.idle? }
  validates :AssetNum, presence: true
  validates :CPU, presence: true
  validates :Disk, presence: true
  validates :Mem, presence: true
  validates :BuyingTime, presence: true
  validates :DeployingTime, presence: true
  validates :Position, presence: true
  validates :ServerType, presence: true
  validates :ServerModel, presence: true
  validates :PCorNot, presence: true

  def idle?
    if ( self.Adapter1IP.empty? || self.Adapter2IP.nil? || self.Adapter3IP.nil? || self.Adapter4IP.nil? || self.Adapter5IP.nil? )
      self.Idle = false
    else
      self.Idle = true
    end
  end
end

于是烦人的事情发生，居然不能保存…… Started POST "/hardwares" for 127.0.0.1 at 2015-07-17 19:45:24 +0800 Processing by HardwaresController#create as HTML Parameters: {"utf8"=>"✓", "authenticity_token"=>"UpMreG5ZvfvQDF5uJp9bX09Uz9nPNW fx9biD+FYnSiilP29uyQ5dN+Ufl3DsoiOBz+L5uU5JzlNk1bDF2YUU6Q==", "hardware"=>{"AssetN um"=>"11", "CPU"=>"11", "Disk"=>"11", "Mem"=>"11", "BuyingTime(1i)"=>"2015", "Buy ingTime(2i)"=>"7", "BuyingTime(3i)"=>"17", "DeployingTime(1i)"=>"2015", "Deployin gTime(2i)"=>"7", "DeployingTime(3i)"=>"17", "Position"=>"11", "ServerType"=>"11", "ServerModel"=>"11", "PCorNot"=>"true", "ServiceNum"=>"11", "QuickServiceNum"=>" 11"}, "commit"=>"创建该硬件资产"} (0.2ms) begin transaction (0.0ms) rollback transaction Completed 422 Unprocessable Entity in 14ms (ActiveRecord: 0.8ms)

ActiveRecord::RecordNotSaved (Failed to save the record): app/controllers/hardwares_controller.rb:18:in `create'

Rendered /home/thanatos/.gem/ruby/gems/actionpack-4.2.3/lib/action_dispatch/mid dleware/templates/rescues/_source.erb (16.5ms) Rendered /home/thanatos/.gem/ruby/gems/actionpack-4.2.3/lib/action_dispatch/mid dleware/templates/rescues/_trace.html.erb (2.2ms) Rendered /home/thanatos/.gem/ruby/gems/actionpack-4.2.3/lib/action_dispatch/mid dleware/templates/rescues/_request_and_response.html.erb (1.0ms) Rendered /home/thanatos/.gem/ruby/gems/actionpack-4.2.3/lib/action_dispatch/mid dleware/templates/rescues/diagnostics.html.erb within rescues/layout (31.2ms) Rendered /home/thanatos/.gem/ruby/gems/web-console-2.2.1/lib/web_console/templa tes/_markup.html.erb (0.3ms) Rendered /home/thanatos/.gem/ruby/gems/web-console-2.2.1/lib/web_console/templa tes/_inner_console_markup.html.erb within layouts/inlined_string (0.4ms) Rendered /home/thanatos/.gem/ruby/gems/web-console-2.2.1/lib/web_console/templa tes/_prompt_box_markup.html.erb within layouts/inlined_string (0.2ms) Rendered /home/thanatos/.gem/ruby/gems/web-console-2.2.1/lib/web_console/templa tes/style.css.erb within layouts/inlined_string (0.3ms) Rendered /home/thanatos/.gem/ruby/gems/web-console-2.2.1/lib/web_console/templa tes/console.js.erb within layouts/javascript (14.2ms) Rendered /home/thanatos/.gem/ruby/gems/web-console-2.2.1/lib/web_console/templa tes/main.js.erb within layouts/javascript (0.2ms) Rendered /home/thanatos/.gem/ruby/gems/web-console-2.2.1/lib/web_console/templa tes/error_page.js.erb within layouts/javascript (0.3ms) Rendered /home/thanatos/.gem/ruby/gems/web-console-2.2.1/lib/web_console/templa tes/index.html.erb (27.1ms)

求指导！非常感谢！

做一个管理系统，用 mongodb 还是 pg？

thanatos — Tue, 14 Jul 2015 17:02:01 +0800

打算做一个管理公司内所有服务器信息的系统。但是在数据设计上有个问题，基本逻辑是：硬件——》操作系统——》IP——》端口——》服务这个顺序，但是在“操作系统——》IP——》端口”这个环节存在 1 对 N 的情况，于是我就不知道表怎么设计了，难道要提前把 N 个 IP 和这 N 个 IP 的 N 个端口的列在 g model 的时候都列出来？这样岂不是会有大量的表空间空白，而且做这个 model 会非常费力。看到 mongodb 的非关系型我感觉 mongodb 才合适，但在咱们社区看了一些文章又犹豫了，好多人说 mongodb 不好，并且说 pg 也能做这种非关系型的。希望请教： 1、我这样的需求哪个更合适？ 2、相对应的方向在 rails4.2.2 中怎么配置……表骂我，我尝试着 mongoid，发现 rails s 都跑不起来了，说找不到方法 active_record……被整懵了。

本人小白，还望各位朋友多多指导，哪怕给个方向自己在 google 都行，谢谢！

希望在 ROR 实现单表内全字段搜索

thanatos — Thu, 09 Jul 2015 16:35:47 +0800

totally 新手，0 开发经验，刚看完 tutor，现在自己做一个小应用练手，里面有一个搜索的功能，卡主了，木有头绪。google 了半天都是介绍一些 gem 的，我没有那么复杂的需求，就是对某个表进行全字段搜索，麻烦给个方向，谢谢！

----------------------------------华丽的分割线------------------------------------------

感谢大家积极回复，感动不已。再清晰一下需求。有一个 information model，用来记录一条条多字段信息；想在页面上实现一个 search bar，在里面键入内容后模糊搜索（我理解为 like）就行，匹配全表全字段。

如果这说的还不足清晰，请指正，谢谢！