传统的三层架构简介各层之间采用接口相互访问，并通过对象模型的实体类(Model)作为数据传递的载体，不同的对象模型的实体类一般对应于数据库的不同表，实体类的属性与数据库表的字段名一致。职责划分层描述User Interface layer(表示层, UI)接受对用户的请求并返回数据，将结果呈现给用户。Business Logic Layer(业务逻辑层, BLL)主要负责接受表现层的请求，进行各种
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1.概述软件是关乎于人的行业，而人依靠文化来长久维系。这个行业很多问题的根源来自以下两个方面:维系人的文化扮演角色的人2.波动的水纹当我们在湖中投入一颗石子时，一道道波纹总会被传播很远……2.1 现象同一产品版本繁多，版本变动频繁。不同版本之间甚至存在不一致，一个版本的变动可能影响到其他版本的正常功能。项目需求难以满足。产品疲于应付不同项目的需求。产品开发人员被抽调出来为不同的项目特定需求进行开发
软件架构的概念：目前未有明确定义的软件架构，但是大致可分为两个流派：组成派和决策派。组成派：组成派认为的软件架构是：将系统描述为计算组件及组件之间的交互。其中“组件”是广泛意义的元素的意思，“组件”可以指子系统、框架、模块、类不同粒度的软件单元，负担不同的计算职责。其特点是：（1）关注架构实践的“客体”——软件本身，以软件本身为描述对象。（2）分析了软件组成及组件之间的交互。决策派：决策派认为软件
Here's to the crazy ones.The misfits.The rebels.The troublemakers.The round pegs in the square holes.The ones w respect...
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2023-02-23 09:08:38
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https://www.enterprisedb.com/well-known-databases-use-different-approaches-mvcc Well-known Databases Use Different Approaches for MVCC Well-known Data
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#include
using namespace std;
const int maxn = 60 + 10;
int n,start[maxn],finish[maxn];
long long f(int* P,int i,int final_){
if(i==0) return 0;
else if(P[i]==final_) return f(P,i-1,final_);
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2022-08-05 15:39:49
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## 使用不同的Python版本
Python是一种流行的编程语言，但是在不同的项目中可能需要使用不同的Python版本。有时候，旧版本的Python可能更适合某些特定的应用程序，而新版本可能具有更多的功能和性能优势。在这种情况下，我们需要能够在同一台计算机上同时安装和管理多个Python版本。
### 安装不同的Python版本
在安装不同版本的Python之前，我们需要确保计算机上已经安
# Understanding why certain tasks require a different Python version
Python is a widely used programming language known for its simplicity and ease of use. However, there are times when certain tasks
Everyone who's for the patience involving going into university should become aware of which often qualifications will be most sought after simply by companies. Year in year out, businesses as well as
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2012-10-25 20:15:13
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SELECT ....FROM A LEFT SEMI JOIN BON (A.col1 = B.col2)WHERE ..."If A.col1 is of DOUBLE type, but B.col2 is of BIGINT, will print WARNING: Comparing a bigint and a double may resul
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2015-05-06 15:06:37
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Given a string S, find the number of different non-empty palindromic subsequences in S, and return that number modulo 10^9 + 7. A subsequence of a str
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要获取更多Jerry的原创文章，请关注公众号"汪子熙":
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2022-04-18 10:03:55
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There are following types of sales document in EPR system:Quotation(QT)Cash Sale(CS)Rush
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2022-12-06 14:51:48
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原文链接：http://developer.android.com/training/multiscreen/screensizes.html
作者：
完成时间：2012年9月11日
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2012-12-30 15:04:29
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1.What is Cygwin ? a large collection of GNU and Open Source tools which provide functionality similar to a Linux distribution on Windows. a DLL (cygwin1.dll) which provides substantial POSIX API fun
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2014-03-22 23:22:00
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Given a string of numbers and operators, return all possible results from computing all the different possible ways to group numbers and operators. Th
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2016-12-17 23:56:00
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Don't just accumulate knowledge, apply it.You will never really know or understand something until you use it. Make little demo programs that use the ...
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2014-11-29 16:39:00
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Created by Jerry Wang, last modified on Jun 09, 2015In saved query persistence table, you can see there are three kinds of saved query:If you create several queries and mark one of them as "Defaul...
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2021-07-15 16:40:56
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Created by Jerry Wang, last modified on Jun 09, 2015In saved query persistence table, you can see there are three kinds of saved query:If you create several queries and mark one of them as "Default Se
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2022-04-21 16:08:30
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B. Different RulesNikolay has only recently started in competitive programming, but already qualified to the finals of one prestigious olympiad. There going to be n participants, one of whom is Nikola
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