On 23/08/2009 3:08 PM, Itzchak Raiskin wrote: > Hi > 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?
Specify with some precision what tables of data you expect to have: create table terrain_data (id, x, y, height) -- ?? create table line (?????) How is the terrain data expressed? I.e. are "cordinates" (lon, lat) or something else? Height above what in what units? What is a "line"? 2D or 3D? Note you say you have hundreds of lines but don't say how they are related to the terrain data ... Explain "get a vector with all heights point along this line" in mathematical terms Explain "for each point along the line" _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
