An Entity Data Model Based Methodology For The Development Of Information System

Entity Data Model (EDM) is a new kind of conceptual model developed by Mircrosoft in Visual Studio.NET 2008, it is a Platform-Independent and executable conceptual model. At present, EDM is mainly used for information integration, so Microsoft has developed tools for transforming Platform Specific Models, such as Relational Data Model (RDM), to EDM.In the methodology for the development of information system based on EDM, EDM is used as a conceptual model for database designing as well as a middle layer for database accessing, the database is accessed thtough EDM. But currently there are few researches on EDM as a conceptual model used for database designing. In order to make good use of EDM for database designing and support information system development based on EDM more efficiently, a transformation tool for transforming EDM to RDM is needed.The mapping rules and transformation algorithm for transforming EDM to RDM are introduced in this thesis. The analysis and transformation tool for transforming EDM to RDM is designed and implemented.Firstly, the basic concept of Entity Framework and EDM is deeply reaserched and analyzed, the characteristic and represation of each element in EDM are introduced in detail. The basic technology for database designing by using EDM as a database conceptual model is presented according to the characreristic of EDM. This technology is similar to database designing technology based on tranditional ER model while has its own characterisitic. Secondly, the transformation from EDM to RDM is mainly researched in this thesis.The mapping rules and transformation algorithm from EDM to RDM is presented, this is the foundation of the transformation from EDM to RDM. According to the mapping rules and transformation algorithm, the transforming tools from EDM to RDM is designed and implemented in this thesis. Finally, some basic technologies for information system development based on EDM are introduced; they mainly include the database access technology of ADO.NET Data Services and database access method of LINQ (Language-Integrated Query).This study shows that, EDM as a basic model for developing information systems, acrosses the whole process of the information system development. The transformation tools for transforming EDM to RDM is designed and implemented in this thesis. It can make better use of EDM as a conceptual model for database designing.