Research And To Maintain Consistency Of Data Based On The Com Gis Applications

The task was put forward the consistency problem of data managerment of GIS application.whose must handle spatial data and attribute data.Usually for be stored and accessed easily.in most GIS application,spatial data is stored in files of some formats.and attribute data is stored in DBMS on the other hand.Two parts of data is linked by common code.This linking data structure could destroy the consistency of spatial data and attribute data,and result in the failure of querying from one side to the other side of data. To resolve this problem,with study of component gis which is most recently development of gis, the paper brings forward a thought of a single corn-based interface to access both spatial data and attribute data.Refering to OpenGIS standard,the paper accomplishes the interface model of this component and the realization of objects inside,provides a effective method to maintaince consistency of data in (ilS.In the design of this component,the paper resolves some problems,such as how to made a COM.access of spatial data in different formats,trasaction in the file access etc. To improve the geoprocessing transactions.the interface design conform to OpenGIS Specification .This component is one of base components in component gis,providing the managerment of spatial data and the basic access ability.