The Application And Research Of Object-Oriented Technique In RDBMS

The administrative issue of large engineering sophisticate data are commonly confronted in new computer application field and management information system or OA etc traditional field.Dependence on the traditional database system is difficult with competent.Therefore,the advanced object_oriented mechanism and method combination with database technique into new generation object_oriented database management system is the necessary result of the development of OO technique and database management. There are two stategy for OO technique appliance to database. one way is to design completely new OODBMS;Another way is to expand traditional database to ORDBMS with OO speciality.At present,the OODBMS technique is not mature,and present some problem and limitation.It lacks the support of the solid formal theories,feasible standard,and database function,so that the compatibility and portability of product is poor,that is the main handicap for abroad application.Although it can used for the development of the applied system with sophisticat data type,it isn't compatible with RDBMS and doesn't provide the gateway by which OODBMS and RDBMS can transform mutually.Meanwhile,it lacks the functional specialty so that it is powerless for accomplishment of OO tasks with traditional database.The ORDBMS is the extension of traditional RDBMS,which introduce the OO ideology into the database to realize the storage of complicated object.But ORDBMS doesn't support the storage of object method,so it is not pure OODBMS in some meaning.Because of the limitation of OODBMS,now people would rather select RDBMS to develop OO application.RDBMS is based on firm mathematics set theory with simple and clear data structure,and powerful query function,so it has become the basic technology for realization of information system.But RDBMS can only manipulate data,is incapable of storage and access of object.That cause the result of the analysis and design with OO method can't realize in RDBMS.This paper put forward a method which can realize the OODBMS by using the object layer which is encapsulated between the application and the RDBMS when developing a OO application system.The basic thought is follow:Using the OOPL to produce a interface layer (persistence layer) which cancombine with RDBMS below that to manage the storage and fetching of entity object in RDBMS,so the operation for the storage of entity object is transparent for the control object,which only communicate with it.In some sense ,that realize the OODBMS.The persistence layer story the static part of object through the object/relation mapping rule and inherit the common database interface to realize the behavior when story a object.We bring forward a CASE tool concept which automate the generation of persistenc class in order to develop a OO application with persistence layer.The auto class generator can improve the efficiency and reduce the error probability.In order to efficiently and fast design the persistence layer and auto class generator,we adopt the newly USDP.USDP give out a process guideline based on UML for software development.It can support the whole software development lifecycle and improve the efficiency of software development.