Ian, I thought that there was a pretty simple answer to this, but it seems as though I have imagined some non-existing functionality.
Assuming that you have a Spatialite db containing a point data set, and you have a MapServer layer that draws this, I think that I have a solution for you. (This also assumes that OGR supports reading linestrings from Spatialite). PostGIS has the ST_MakeLine() function that allows you to create linestrings out of point geometries. The current version of Spatialite doesn't have anything like this (although since I have mentioned it on the Spatialite list, it could be there soon...) So, this SQL employs some workarounds, but may work: SELECT LineFromText('LINESTRING(' || group_concat(X(geometry) || ' ' || Y(geometry), ',') || ')') FROM datapoints ORDER BY fix_date; If performance is a problem, I would build a Spatialite line dataset and rebuild it every time your point dataset changes. David. -----Original Message----- From: mapserver-users-boun...@lists.osgeo.org [mailto:mapserver-users-boun...@lists.osgeo.org] On Behalf Of Stephen Woodbridge Sent: Thursday, December 16, 2010 10:44 AM To: Ian Walberg Cc: mapserver-users@lists.osgeo.org Subject: Re: [mapserver-users] OGR data layer type - points and lines On 12/16/2010 10:51 AM, Ian Walberg wrote: > Ah, ok let us look at that. > > I do believe the data source we have has data in the format POINT > (-118.550003051999994 34.016666412399999). > > What is the format for line data? I'm not sure, I have not used the OGR connection. Assuming it is returning WKT where points are: POINT(-118.550003051999994 34.016666412399999) then lines would be: LINESTRING(-118.550003051999994 34.016666412399999,-118.560003051999994 34.016666412399999,...) -Steve > Thanks > > Ian > > -----Original Message----- > From: mapserver-users-boun...@lists.osgeo.org > [mailto:mapserver-users-boun...@lists.osgeo.org] On Behalf Of Stephen > Woodbridge > Sent: Thursday, December 16, 2010 6:57 AM > To: mapserver-users@lists.osgeo.org > Subject: Re: [mapserver-users] OGR data layer type - points and lines > > I do not believe that this is possible. > If you want to draw lines you have to create a data source the returns > lines not points. > > The problem is that mapserver draws features and each point is a > feature. It does not have a mechanism that can read a data source and > aggregate the point features into a single line feature. > > I have seen posts on the PostGIS list for SQL that can do this. You > might ask on the GDAL list if there is a way to do this. Or if you can > use PostGIS, then you can find the SQL in the archives or ask again. > > -Steve W > > On 12/16/2010 1:00 AM, Ian Walberg wrote: >> Hello list, >> >> Using an OGR connection to an sqlite data file we can get point and >> labels to draw successfully. >> >> However when we try and draw a line using the point data we do not get >> anything drawn. >> >> Layer details below. >> >> Thanks >> >> Ian >> >> LAYER >> >> NAME ogr_points >> >> STATUS DEFAULT >> >> TYPE point >> >> CONNECTIONTYPE OGR >> >> CONNECTION "points.sqlite" >> >> DATA "DataPoints" >> >> CLASS >> >> NAME "From OGR" >> >> COLOR 255 0 0 >> >> STYLE >> >> SYMBOL 'City' >> >> SIZE 5 >> >> COLOR 0 255 255 >> >> END >> >> LABEL >> >> COLOR 255 255 255 >> >> OUTLINECOLOR 0 0 0 >> >> TYPE truetype >> >> FONT Unicode >> >> SIZE 16 >> >> ANTIALIAS TRUE >> >> POSITION AUTO >> >> END # end of label >> >> END >> >> END >> >> LAYER >> >> NAME ogr_line >> >> STATUS OFF >> >> TYPE line >> >> CONNECTIONTYPE OGR >> >> CONNECTION "points.sqlite" >> >> DATA "DataPoints" >> >> CLASS >> >> STYLE >> >> COLOR 255 22 22 >> >> WIDTH 2 >> >> END >> >> END >> >> END >> >> >> >> _______________________________________________ >> mapserver-users mailing list >> mapserver-users@lists.osgeo.org >> http://lists.osgeo.org/mailman/listinfo/mapserver-users > > _______________________________________________ > mapserver-users mailing list > mapserver-users@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/mapserver-users _______________________________________________ mapserver-users mailing list mapserver-users@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/mapserver-users _______________________________________________ mapserver-users mailing list mapserver-users@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/mapserver-users