PowerDesigner在数据库综合性实验中的应用研究

以"学生成绩管理系统"为例,进行模型设计,阐述了需求模型、业务模型、概念模型、物理模型、生成数据库脚本及测试数据的主要设计过程。     

课表编排系统中数据库的设计与实现

论述了课表编排系统数据库的概念模型、逻辑模型以及物理模型的设计和规范化设计。为防止不符合语义的错误数据的输入输出，数据库设计中采用了主键约束、唯一性约束、外键约束、缺省、规则和触发器等技术来保护数据库的完整性。     

支持数据库动态建模的框架系统研究

概念模型设计是数据库设计过程最重要的环节,E-R模型因为具有简洁和清晰的优点成为目前主要的概念模型设计方法.但是,E-R模型不支持动态建模,缺乏灵活性,因而不能满足某些特殊部门的应用要求.因此,致力于支持数据库动态建模的框架系统研究,提出一种新的以面向对象方法为主要思想的动态建模框架.该方法给出一套能动态地对信息进行完整描述的概念模型,从而得到一种灵活、强大的数据库概念模型设计框架,实现数据库的动态建立.     

基于有向图的数据流图的E-R模型构建方法

建立概念模型是数据库设计的重要步骤之一,E-R模型是数据库设计中广泛采用的概念模型。本文提出利用业务分析过程中形成的数据流图,把数据流图抽象为有向图,从而构建E-R模型的方法。在大型系统数据库设计过程中,使用这一方法可以快速构建局部应用的E-R模型,大大缩短数据库设计过程中构建E-R模型所耗费的时间。实例验证了本方法在实际工程项目中的实用性和有效性。     

数据库设计工具PowerDesigner的研究与实践

本文介绍了一种新的数据库设计工具Power Designer的编程设计方法,对概念数据建模、物理数据建模、面向对象建模的原理进行了分析,在对“物资管理系统”的需求做了分析之后,建立了概念模型,然后使用概念模型生成物理模型,并在物理层让它们与SQL Server 2000建立了连接,最终在SQL Server 2000中成功生成了数据库。     

基于PowerDesigner的数据库设计与建模

数据库的设计在整个数据库的使用是很重要的一部分,本文着重介绍了基于PowerDesigner进行数据库设计与建模,从用户数据库的设计阶段:需求分析、数据流图、E-R图、数据字典,到用户基于PowerDesigner的建模阶段:概念模型CDM、物理模型PDM、产生测试数据生成脚本,最后在SQL Server2000中执行脚本,形成数据库中的数据表。通过基于PowerDesigner数据库的设计与建模,我们能够合理的设计数据库的结构以及方便地对数据库建模。     

基于数据仓库的高中学生成绩分析模型设计

针对高中学生成绩的特点,结合数据仓库的设计方法给出了学生成绩分析数据仓库的概念模型、逻辑模型和物理模型,为高中学生成绩分析数据仓库的建设奠定了基础。     

生活必需品监测快速反应系统数据库模型设计

本文重点阐述了天津市场运行监测信息系统的数据模型设计的生命周期和设计原则。对天津市场运行监测信息系统的数据模型的设计过程中的概念模型的设计,逻辑模型的设计,物理模型的设计,数据仓库的生成进行了详细的介绍。     

代码自动化技术的应用研究

在中小管理信息系统开发中用户对需求的描述存在动态性的问题。针对这种情况,提出一种以数据库为基础的软件自动化开发框架。框架包括软件三层架构的设计、缓存数据库、代码生成引擎、通用代码模版的设计和数据库概念模型设计的约束条件,实现基于数据库物理模型的软件源代码的自动生成。通过在农产品质量安全监测系统实际应用,分析结果表明,框架在实际项目中的应用表明能有效适应用户需求变化,降低开发成本,提高软件质量。     

代码自动化技术的应用研究

在中小管理信息系统开发中用户对需求的描述存在动态性的问题。针对这种情况,提出一种以数据库为基础的软件自动化开发框架。框架包括软件三层架构的设计、缓存数据库、代码生成引擎、通用代码模版的设计和数据库概念模型设计的约束条件,实现基于数据库物理模型的软件源代码的自动生成。通过在农产品质量安全监测系统实际应用,分析结果表明,框架在实际项目中的应用表明能有效适应用户需求变化,降低开发成本,提高软件质量。     

Using an entity model to drive physical database design

Logical relational database design, because of its implementation-independent nature, has been successfully formalized. Physical relational database design, because of its implementation-dependent nature, has remained largely unformalized and disconnected, not only from logical design but also from conceptual database design. The paper suggests a model for the physical design process that has proven useful in a number of practical development projects. The model demonstrates that a seamless join between conceptual, logical and physical design work is feasible. It illustrates how the process of annotating a conceptual model with physical detail provides a useful framework for driving the process of physical relational database design.     

数据库逆向工程方法比较与分析

从物理数据库恢复概念数据模型的过程称为数据库逆向工程(DBRE)。本文首先介绍了ER模型的主要构造子,然后描述了数据库逆向工程的概念和处理过程。接着分析了前期研究人员提出的多种逆向工程方法和主要CASE工具逆向工程方法的特点。     

油气勘探钻录测数据库平台设计

在了解钻录测数据需求分析的基础上,设计基于三层体系架构的钻录测联合数据库平台。根据钻录测数据多源、海量的特点,提出以油气勘探为目标的钻录测数据库的概念模型和物理模型,探讨数据库平台数据接口的设计,并对数据库平台进行初步实现,利用胜利油田某区块的油气勘探数据进行测试,结果表明,数据库平台能有效管理钻录测数据,实现数据的快速检索,为油田生产提供有力支撑。     

Towards a new approach to secure database design

The problem of designing and managing a secure database system is considered in this paper. The approach which is proposed is primarily concerned with the security information definition and management in a database environment. A multiphase design methodology is presented reflecting current proposals of database design methodology. In particular four design phases are proposed: requirements analysis of the security system, conceptual, logical and physical design of security information. The content and the solution techniques of each phase are examined. A database management system architecture is also presented which is suitable to control access rights to the database.     

Handling complex and uncertain information in the ExIFO andNF2 data models

Trends in databases leading to complex objects present opportunities for representing imprecision and uncertainty that were difficult to integrate cohesively in simpler database models. In fact, one can begin at the conceptual level with a model that allows uncertainty assumptions and then transform those assumptions into a logical model having the necessary semantic foundations upon which to base a meaningful query language. Here we provide such a constructive approach beginning with the ExIFO model for expression of the conceptual design then show how the conceptual design is transformed into the logical design (for which we utilize the extended NF² logical database model). The steps are straightforward, unambiguous, and preserve the relevant information, including information concerning uncertainty     

The introduction of a design heuristics extraction method

This paper introduces a novel method for analyzing conceptual design data. Given a database of previous designs, this method identifies relationships between design components within this database. Further, the method transforms these relationships into explicit design knowledge that can be used to generate a ‘heuristic-based’ model of the design domain for use at the conceptual stage. This can be viewed as a knowledge extracting method for the conceptual design stage. Such a method is particularly interesting, as the conceptual stage typically lacks explicit models to describe the trade-offs that must be made when designing. The method uses either principal components analysis or self-organizing maps to identify the relationships, and this paper describes all the elements required by the method to successfully extract and verify design knowledge from design databases.     

Implementation design for databases: the `forgotten' step

Most methodologies for database analysis and design specify conceptual, logical, and physical design as the three major design steps. However, although this three-step approach is popular, there is no consensus on when to use implementation design techniques, such as table partitioning and denormalization. Consequently, these techniques are treated as substeps in one of the three main design steps. This inconsistent treatment may be why many designers frequently rely on their intuition in applying implementation design techniques. Clearly, this ad hoc practice shouldn't continue. Ad hoc anything is not a good idea when designing a complex system. To resolve this problem, the author proposes that we extend the three-step methodology to include a fourth major step: implementation design. In this methodology, implementation design is the process of modifying an “ideal” logical data model (relational or object-oriented) to produce a more machine-efficient, “pragmatic” model: the implementation model. The implementation model, in turn, serves as input to the physical design step. This four-step method will encourage practitioners to resist the ad hoc approach and simplify the other design steps. It will also help in addressing the additional complexity associated with advanced database architectures, such as distributed and parallel databases and data warehouses     

基于Petri网的数据库概念设计模型

在数据库概念设计阶段,E-R图虽然广泛使用,但反映不出对数据的处理要求和数据库的完整性要求.提出了用Petri网建立数据库概念设计模型,把数据及其相关的处理集成在统一的网模型中,而且用事实(死变迁)规范了该模型的数据库完整性.