Geographic Information Systems: An Introduction, 3rd Edition

14.6 Search and Report Generation from Attribute Data

Inquiry in attribute data may be the primary GIS task in daily practical applications, particularly in the operational, maintenance, management, and service sectors. Inquiry calls for a human–machine dialogue in which the user employs various input/output devices and their supporting software. Tailor-made software is employed in some GISs. In others, standard routines such as SQL are employed, particularly in those that access relational databases.

Inquiry of and search for data may be based on logical and arithmetic operations and specific relational database functions, as with projection, selection, and joining. The query criteria may be complex and cover several attribute tables. In practice, responses to inquiries should be displayed in a comprehensible manner, not simply as brief on-screen information. This is particularly true when attribute data are used as a reference source. Consequently, many GISs support a standard report format with fixed headings, column locations, and other layout features. In addition, users may define their own report formats.

Some GISs support report formats that are tailor-made to each application, whereas others use the report function and report form storage facilities of the report generator supported by the DBMS in use. In many cases, reports may be simple. For example, an inquiry may be for the name and address of the owner of a property at a particular address, or for a list of all the ...