On Sun, 23 Aug 2009, Itzchak Raiskin wrote: > I want to use SQLite in a GIS application where I create a database > containing terrain data (coordinates, height). I would like to query this > database with start and end points of a line and get a vector with all > heights point along this line. I can, of course create a query for each > point along the line, but this will be very time consuming as I have > hundreds of lines with hundreds of points. Any suggestions?
Itzik, Other responders have suggested how to query for specific lines, but that will not fulfill the requirements of a GIS. You could create a computer-aided drafting (CAD) application this way, but you need to incorporate coodinate geometry if you want a spatial analytical tool. You need to accommodate a single edge that defines adjacent polygons and store the spatial relationship. SQLite is not the best tool for spatial applications. I suggest that you look at PostGIS, OpenGIS, GRASS, and other well-developed applications. Yes, they use PostgreSQL for the data storage and can store geometric objects as data entities. You are, of course, welcome to reinvent the wheel, but I suggest that you learn something about spatial databases and coordinate geometry if you want an application that actually works. Rich -- Richard B. Shepard, Ph.D. | Integrity Credibility Applied Ecosystem Services, Inc. | Innovation <http://www.appl-ecosys.com> Voice: 503-667-4517 Fax: 503-667-8863 _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
