Object Relational Mapping Engine Design And Implementation

With the complication of enterprise in business, masses of application programming have adopted the Domain Model to develop the software. The Domain Model consists of a group of certain special aggregations, which is induced from the definition of business and is modeled based on the surround of the current business. And these objects intimate to the business conception are the core issue of the application program, based on Domain Model. Storage time might be longer than the creating time. Hence, How to storage the external objects becomes the undressed problem in object persistence technology.In the other hand, if RDBMS are regarded as the method of storing various data aggregatively, it is impossible to store the operation objects directly. There exist the technique obstacles of unable effectively connection between the object data and relational data. To the relevant data, they firstly are organised as flat model. And to the object data,it is much more complex than relational data in single datum, as well as the inheritance and aggregation between class. Hence, there come different ways to address the problems of how to store these business object,and how to match the O/R mapping efficiently. Nowadays, the industry has been adopted various methods to achieve the object persistence, which are so different in performance, interface, and expansibility. One of the primarily application is to achieve the association between the O/R mapping and object persistence by SQL hard-programming tech. The other is to offering the corresponding service by the middleware. Middleware hibernate in open-source storage is a tool of (O/R mapping), which is of connatural deficiency in compatibility, due to the absence in supports of criteria.JDO is a storing criterion of O/R mapping settled by JCP council. And this group of data storage middleware of criteria can mapping the Java object to the RDBMS efficiently. Meanwhile, since the international standard interface s are adopted, JDO is of great superiority in compatibility .In this thesis, analyzing from JDO criteria, based on large-scaled RDBMS LogicSQL, how to design and achieve a data storage middleware according with the JDO criteria in LogicSQL database is debated. And finally, the brief application examples are offered.