如果一个Rubyer想要提供一个功能或某个程序或程序的集合给其他Rubyer使用,这个Rubyer可以创建一个package,这个package就叫做gems. 可以通过gem install安装. https://www.ruby-toolbox.com/ Raisl 本身就是一个gem. gem 'listen', '>= 3.0.5', '< 3.2' 这是说大于3.0.5版本并小于3.2版本. '~> 2.0.0' 这是说最高版本用2.0.0 Gemfile.lock被用于多开发…

偶然一次: 运行rails generate停止不动,网上查找答案,可能是bundle update 之后 spring 版本变化了,和正在运行的 spring 实例不兼容. Spring导致的同样的原因: rails g migration后,窗口显示了生成迁移文件,但文件树结构上没有显示这个文件. rails console停止不动,打不开控制台. 解决办法: 关闭spring, spring stop ⚠️,如果谷歌上查找问题,中文描述问题找不到好的结果,改用英文描述问题,然后搜索. ht…

豆知识扩展: <meta>  https://www.cnblogs.com/chentianwei/p/9183799.html css selector div > p 选择所有父母是<div>的<p>元素. div p 选择所有在<div>内的<p>元素. 个人理解 div.dialog特指类名是dialog的<div>元素 public 文件夹下的html文件是静态网页,通过http://localhost:3000/h…

Naming a Route get 'home/index', as: "different_name" 会得到prefix: different_name代替home_index, 这个是路径的名字. get 'home/ping', to: "home#pong" to方法,定义到哪个控制器的哪个action. 这会改变默认的控制器的action.而控制器会指向view. Paramter 通过浏览器输入的URI Pattern ,可以导向控制器的某个acti…

用generator建立一个手脚架 Representational State Transfer (REST).  具像的状态转存. https://en.wikipedia.org/wiki/Representational_state_transfer RESTful风格的简单的理解: 如何根据一个简单的法则来存取数据.法则包括CRUD的原理和对HTTP的明确定义. redirect_to logger.info "+++ Example +++"  :可以添加log,同时在te…

rails generate model photo title:string album:references 这会产生一个album_id列,当建立belongs_to关联时,需要用到. references算时一种结构,会产生integer. For integer, string, text and binary fields, an integer in curly braces will be set as the limit:  `rails generate model user…

The following are the most suggested Oracle Certifications for Oracle Application Developers in Forms and Reports and as you already know that Oracle Forms 12c also released, so it is going to be used in long run. Oracle Certified Professional, Oracl…

I have written many posts related to triggers in Oracle Forms, I have given examples for Form Level triggers, Data Block Level triggers and Item Level Triggers. And in this tutorial I am just giving the simple tutorial to how to create a trigger in O…

To attach a PL/SQL library in the Oracle Forms follow the following steps:1. Click on Attached Libraries node in Object Navigator and then click on + button. 2. Attach Library dialog window will open, then click on the Browse button to locate the .PL…

On May 28, 2014, Xamarin introduced Xamarin.Forms, which allows you to write user-interface code that can be compiled for the iOS, Android, and Windows devices. The Xamarin.Forms option Xamarin.Forms supports five distinct application platforms: iOS…