National Center for Geographic Information and Analysis

The three papers contained in this report show three different perspectives of interactive query languages for geographic information and analysis, an emphasis of the NCGIA’s Research Initiative No. 2 on "Languages of Spatial Relations." They are published as a technical report to make them accessible to readers as a whole so that they can make comparisons between the different approaches.

The first paper, "Concepts of Spatial Objects in GIS User Interfaces and Query Languages," was presented at GIS/LIS ’89 in Orlando. It investigates the requirements for a GIS query language from a user’s perspective. The second paper, "Spatial SQL: A Query and Representation Language," shows how such a GIS query language can be designed as an extension of the well-known relational query language SQL. Finally, the third paper, entitled "LOBSTER: Combining AI and Database Techniques for GIS," is a reprint of an article published in Photogrammetric Engineering and Remote Sensing, Vol. 56, No. 6, June 1990, pp. 919-926. It reports on the implementation of and experience with a prototype of a spatial query language based upon the Prolog programming language.