Research And Implementation On The Domain Data Model

Since 1960s, database technology has been widely used and it has become one of the most rapidly developed subjects in computer science. More and more MIS and utilities are built based on the database. It is significant in improving enterprise's efficiency and people's living condition.Data Model is the core of a database system. It has more than 40 years'history from universal data model's appearance up to now. It came through the following development phases: network, hierarchical, relational and object oriented model. Relational data model and object-oriented data model are prevalent now. This paper analyses some new applied increase points in database field. But the universal data model cannot support these hot points effectively. The author considers the highly abstract degree of universal data model is the main reason that leads to the weak support, so universal data model cannot serve the real application well.Because the existing data model can't work perfectly with given application, this paper brings forward domain data model(DDM). DDM's structure is more fit for given applied field. It helps us to design and develop MIS easily and it can solve the problem of data access control on applied layer. We firstly talk about what is domain and data model, and define their use range. Then beginning with the introduction of characteristic of domain and data model, we analyze their action in MIS development. To find the relations of domain and data model, we combine them together, bring forward and explicate the definition of DDM. After that, this paper explicates formalization expression and abstract structure of DDM. On the basis of these conceptions, this paper studies manipulation method of domain, relations between domains, evolvement of domain's relations and data operation...