iDragon

摘要： SQL1. SELECT id, name, FROM Products; //Retrieving Multiple or Individual Columns from the specific DB-table2. SELECT * FROM Products; //Retrieving All Columns (* stand for / means all columns)3. SELECT id, name, price FROM Products order by price, name; //Sorting By Multiple Columns name//Order by 阅读全文

摘要： JVM & BytecodeAbstract & ObjectObject in Java(1) 所有东西都是对象object。可将对象想象成一种新型变量；它保存着数据，但可要求它对自身进行操作self-operation(this pointer is always as parameter pssing to function called on object)。理论上讲，可从要解决的问题身上提出所有概念性的组件，然后在程序中将其表达为一个对象。(2) 程序是一大堆对象的组合combination；通过消息传递，各对象知道自己该做些什么。为了向对象发出请求，需向那个对象“发 阅读全文

摘要： Reference to: http://agilemanifesto.org/iso/en/Individuals and interactions over processes and toolsWorking software over comprehensive documentationCustomer collaboration over contract negotiationResponding to change over following a planTwelve Principles of Agile Software We follow these principle 阅读全文

摘要： JVMAnalysis & DesignThe object-oriented paradigm is a new and different way of thingking about programming.Most of the analysis and design methodologies are intended to sovle the largest of problems. Remember that most projects don’t fit intot hat category, so you can usually have successful ana 阅读全文

摘要： Programming has its own methodology.Layering is everywhere in real life,this why the pruchase and sale exist. Layering, Insert additional indirection通过分层layering/add indirection来体现 "有一个" 或 "用...来实现’ composition /composite 使某个类的对象成为另一个类的数据成员，从而实现将一个类构筑在另一个类之上，这一过程称为 "分层"(Laye 阅读全文