Validation of query expression based on Regular Expression

As the technology in GIS and Computer Science develops, more and more applications of GIS have been put into practice. And many general spatial databases has been constructed which are connected with development of social and economy tightly. With complete general spatial databases, the priority of facilitating and improving GIS application is to retrieve data effectively and output data efficiently and accurately. The current popular GIS database products only include limited functions of data Retrieval. The main drawback is that data retrieval can only be operated on one dataset at one time. Function of retrieval for whole database is not available yet. So developing function of data retrieval for database is desirable greatly in which the problem is how to validate query expression to ensure successful data retrieval operation. The author introduced a method of using Regular Expression to validate query expression. A system based on ArcGIS was developed which had been put in practice and achieved great success. In this paper the method is discussed in detail, practice has proved that this method has complemented and consummated the insufficiency of current GIS products adequately.