The Research Of Database Generating Engine And Object/Relational Mapping Based On .Net

This paper derives from the research and development of Management Information System (MIS) Auto Generator. By analyzing MIS System, a typical model of MIS is summed up. Based on this typical model we develop a MIS Auto Generator on the platform of .Net. The MIS Auto Generator includes three models: the engine of user interface, the engine of database generator and the engine of code generator. This paper focuses on researching the engine of database generator and the component of Object/Relational Mapping (ORM).This paper analyzes the relation model and compares different relational database, then proposes a method of achieving the engine of database generator which can run on different relational database. This paper also describes the conception of this method. We use factory mode to design this generator's structure, finally, we develop this engine based on .Net.According to the requirement of user interface, the author design and implement an independent Object Persistence Layer (OPL). OPL is designed to implement the ORM, it can operate the object by saving, updating, querying and deleting. Also, using OPL, the data can be modeled in Object Model, and OPL stores these objects to relational database.This paper proposed to design the ORM as an independent component, so it can be used in applications that support component. It is easy to reuse ORM in other applications. Further more, ORM can be easily extended and such extension will not cause the recompilation of applications that use ORM.This paper also analyzes the common method of data access and the designing target of data access layer in ORM. Using abstract factory mode, we masks the immediate relationship between applications and relation database in the bottom, and we develops an available component of data access layer. This component is not binding on certain relational database; the persistence mechanism implemented by it in the relational database is universal. We can use this component in many applications, and it shows good compatibility.