The Research And Realization Of MapGIS7.0 Validity Rules Manager

GIS data can be categorized into spatial data and attribute data. Spatial data is the abstract of geographical entity in the real world. Geographical entity must act in accord with some kinds of spatial or logical rules, for example, the core city of a province must be inside the province's administration area etc. Attribute data is the description of geography entity property, it must also follow some principles, for example, the sex of human being must be man or female etc. The relation principles and logical rules must be maintained by geo-database.GIS spatial data deal with ability is stronger and stronger along with the development of computer technology and database technology, and the quantity of spatial data is larger and larger, it is GB grade before but now comes to a great capacity for liquor magnanimity. The cost of maintain the large spatial data is so great by the follow reasons: there may be some man-made mistakes when data is put into geo-database,and the spatial relationship of geographical entity may be broken up when the data changed,all of these will result in data becoming to be wrong, inconsistent and un-integrity, and then reduce the quality of geo-database data. Relation database offered some methods to resolve the problem of maintain the data validity and integrality, for example, restrictions and rules etc. Geo-database is an especial database. It needs some especial rules to maintain the validity and integrality of data. It is necessary to institute a kind of validity rule to make sure data validity when it is put into geodatabase and data integrality when it is changed. Validity rules are an important approach to improve the quantity of geo-database data.A new generation of large GIS product MapGIS7.0, developed by Wuhan Zondycyber Science and Technology Company, is the great spatial information GIS basic software faced to network. The relation database managing entirely method and design thought faced to object are used in it.Aimed at the character of geo-database, this article researches and realizes a validity rules manager used the frame of MapGIS7.0 to maintain the validity and consistency of data in the geo-database. Concretely, the research work and innovation of this article are as follow:(1) Retrospect to the development of GIS simply, point out the problem on maintain data consistency in geo-database, explain why does it need to research and realize the validity rules manager of geo-database, analyze the research actuality at home and abroad particular, point out the vice of maintain data consistency in GIS software, at last, summarize the research of this article.(2)Introduce the spatial data model faced to entity of MapGIS7.0 particular. Point out the concepts of geographical entity,feature and object, introduce the concept delaminating of spatial data model faced to entity, explain the correlative concepts of feature class,object class, annotations class,simple feature class,relationship class,feature class dataset ect, analyze the data organizing mode of spatial data model faced to entity, expatiate the data organizing character of complex feature model and simple feature model.(3) Researching on the basic concept of validity rules. Analyze the character of geo-database data,research the sort of validity rules according to the request of the geo-database integrality, and discuss the concepts,character and effect area of attribute rules,relationship rules,topology rules and connection rules particular, research the sort of unitary topology rules and duality topology rules mostly,design four point topology rules,eleven line topology rules and nine area topology rules including unitary topology rules and duality topology rules particular,introduce the application of these topology rules.(4) Researching on the storage model and validation model of geo-database validity rules, point out the storage method of validity rules based on the data storage character of MapGIS7.0, use file and database to storage data, design data structure and data table to storage validity rules, analyze the validation flow of attribute rules, relationship rules and topology rules, research the method of point to line topology construction, line to line topology construction and line to area topology construction, and research the validation arithmetic of topology rules.(5)Design and realize the validity rules manager based on the system frame of MapGIS7.0. Design the system frame of validity rules manager according to the system frame character of MapGIS7.0, analyze the functions which validity rules manager must have, design the interface of the functions, and then realize the validity rules manager.Finally, summarize the research work of this article, point out the shortage of the research at present, and then prospect the development of validity rules manager.