Maintenance System For Heterogeneous Distributed Database Based On Web Service

Some operations, such as "Insert", "Delete", "Update" and "Select", are very important for the maintenance of database. The maintenance of heterogeneous distributed database is very difficult because of the heterogeneous distributed issues. With the development of Internet, it is very important to research and develop the maintenance system based on Web.In this thesis, the common design method of database is analyzed in detail. And then a new design method for application development is proposed, which is based on metadata. A new data dictionary for application is designed, which makes the database application system to be independent on the database structure, and to be adaptive to relational database model. A constraint accessing security model based on roles is introduced, which improves the security of the database system. It extends the security to triple level.A new design scheme is provided, which is integrated three methods: the design method of application based on meta-data, the design method of EJB Web Service component and the constraint accessing security model. It is used to the development of heterogeneous distributed database maintenance system. The advantages of the scheme are discussed, and an application system based on Web Service is developed with the characteristics of generality. The application is used to Heilongjiang food-prevention decision support system, which implements the distributed data management. It solves effectively the problem about the long-distance maintenance for magnanimity dataIn short, the application system has a multi-level architecture, which is based on meta-data design method. It has certain reference meaning to the development of database application system.