Application of object-oriented database system design technology（應(yīng)用面向?qū)ο蟮臄?shù)據(jù)庫系統(tǒng)設(shè)計技術(shù)）

1、 Application of object-oriented database system design technologyAbstract: The basic idea of object-oriented technology and development process, describes the implementation of object-oriented technology. A detailed discussion with concrete examples in the database system architecture design and det

2、ailed design of object-oriented technology, the use of surface to the object database system analysis and design methods, the use of the UML tool to establish a specific object model, gives a more general-purpose database system development model systems designed to use the mode reuse, and easy to m

3、aintain, in order to effectively improve the quality of the development of database systems. Keywords: object-oriented database system designed object model An object-oriented basic concepts of 1.1 object (Object) method (Method) and message (Message) Objective world is constituted by the entities i

4、n the objective world and their mutual relationship between the objective world of abstract entities for objects in the problem space we need to solve different problems, we face the object is different, so the object is not fixed. A book can be an object, a library can also be an object. Dynamic po

5、int of view, the object and its operation is the behavior of the object, an object is usually defined as: the object is operating on a set of information and its above description. Private data structure and processing, these processes also known as operations (Operation) or method (Method), includi

6、ng control and process private data, said the state of the object, the state only by a private operation to change, whenever the need to change the object the state, you can only send messages to the object by other objects. Message is used to request the object to perform an operation or to answer

7、certain requests for information, the message unified data flow and control flow, program execution is against the objects pass the message that the message in the form of news mode. different messages of the same message mode, the interpretation and processing by the same object are the same, but o

8、perating results due to the different state of the object. a message of a schema defines object, all messages mode and message mode processing capabilities, define the external characteristics of the object. 1.2 (Class), instance (Instance), inheritance (Inheritance) In the objective world, there ar

9、e many things that have the same characteristics, such as: cars, buses, trucks, etc., can be classified as a motor vehicle. From the object point of view, common property, common operational nature a collection of objects is class, and a single object is an instance of the corresponding class. For e

10、xample: the book is a class, a specific book, such as << >> of object-oriented analysis is an instance of the class, any object is instance of a class, and inherit the class definition of private data and operations. This is the inheritance of a class is essentially defined an object typ

11、e. Constitute a class hierarchy, the relative upper superclass, the relatively lower subclass, subclass inherit the super classs private data structure and operation at the same time can have its own private data structures and operations. If a subclass has only one super class is called single inhe

12、ritance, then the class shared superclass attributes and operations. Class and inheritance are important concepts in modern software engineering, software reusability, reusability of program components of the inherited class attributes and operations in many industrial observation believe that reusa

13、ble software is not to create a tradition over the program (subroutine library), but achieved through the establishment of a “class library”. 1.3 package (Encapsulation) The encapsulation of the object is reflected in the following areas: Object with clear boundaries: the scope of the objects intern

14、al software (data structures and operations), limited to within the boundaries of objects with a unified external interface: the interface of the object (message mode) to describe the interaction between the object and other objects are not open to the internal implementation of the object: the obje

15、cts implementation gives the details of the object provides the functionality of external objects can not access this feature details. Information hiding is an important concept to emphasize in the software development process, the encapsulation of the object reflects this concept. This convenient s

16、tarting a object-oriented technology developed by the design of software maintainability greatly improved software technology to the pursuit of one of the goals. Share the free paper download center surface to the object in the database design process Object-oriented technology is

17、 an important application in the database system is object-oriented database system, with the expansion of the database applications, new application areas, such as computer-aided design, computer-aided software engineering, hypertext applications proposed simulation of complex objects, the new dema

18、nds of the complex behavior of the simulated object. a traditional relational database is difficult to meet these requirements, application development to promote the study of the database of new technologies, object-oriented database systems have emerged. Object-oriented technology in the database

19、system is another important application of object-oriented database application development tool. With the development of client / server architecture, as well as the needs of enterprise-wide database applications the traditional relationship database application developers to put forward new requir

20、ements on database application development tool, to support the development of graphical user interface (GUI) and reuse of software components, the development teams work, the scalability of the application system, and scalability. echoes with these requirements, database vendors and tools developer

21、s of object-oriented technology to the relational database application development tool, the introduction of object-oriented database application development tool, and put into the market, in a relational database application development using object-oriented technology provides a strong support. Da

22、tabase management system development process including requirements analysis and system design in two phases, after the completion of a needs analysis, database design, database design is directly related to the development of the system late in the traditional demand analysis uses data flow diagram

23、s, database design using the ER model, requirements analysis and database designer difficult to reach agreement on the use and understanding in the requirements analysis phase, object-oriented analysis, database design, object-oriented design methods, needs analysis phase of the object model can be

24、naturally transformed into the structure of the database using the Unified Modeling Language (unifiedmodelinglanguage, UML) to support object technology can solve problems in database design, UML language to describe real-world objects and their the relationship between support application developme

25、nt, the UML has become the standard modeling language for object-oriented technology, including the three categories for a total of nine kinds of different, interrelated diagram: static diagram (use case diagram, class diagram, object Figure), the dynamic diagram (activity diagram, collaboration dia

26、gram, sequence diagram, state diagram), and the block diagram (component diagram, diagram), respectively, describe the external features of a software system structure, internal static and dynamic structure and code of the physical compared to the structure. method in object-oriented approach althou

27、gh it is difficult to grasp the deep and abstract analysis, but more effectively because of its consistent approach in the requirements analysis and system design stage system module design and software has become can be reused therefore become a popular technique in software engineering. In short,

28、with science and technology of progress and economic development, more and more extensive use of object-oriented technology in software development today, using the UML language object-oriented technology for the design of the database system has a very important role. Using UML language to describe

29、 the external features of the structure of the database system, internal static structure, dynamic structure and the physical structure of the program code, mature object-oriented technology to improve the efficiency and quality of the database system design, improve the reusability of the database system software development resistance and maintainability. References: 1 WU Ji Jin Maozhong. UML-oriented object M Beijing: Beijing University of Aeronaut