All, I have a bunch of individual LINE segments in Postgres and want to display them via MapServer like so:
First: * Get a chunk of them based on a set of IDs (a set of three for example) and a begin/end timestamp (got this figured out already) * Take the result and combine up the separate line strings into multi-segment (grouped) lines ordered by ID, timestamp (got this figured out for individual IDs) * Add a random number to each grouping of multi-line string rows for dynamic color-coding of each group. (got this figured out for individual IDs) * Have results output as three rows, one for each multi-segment line. I'm lost on the method to do the last piece. Mostly it relates about how to approach which piece first. Seems like a straightforward SQL, but I've tried a few different things, and it falls part each time for me. Anyone have examples of something like this to start from? The pertinent Mapfile fragment, I know this only color codes each individual segment at the moment. VEH_IDs are passed into the MapFile from CGI (vname=veh_id in DB): DATA "the_line FROM (select the_line, vname, acqtime, trunc(random() * 4 + 1) rnum from loc) as foo USING unique vname using SRID=4326" FILTER " vname in (%veh_id%) AND acqtime > '%time_idx1%' AND acqtime <'%time_idx2%' " VALIDATION 'time_idx1' '.*' 'time_idx2' '.*' 'veh_id' '.*' ## veh_id='100','200','300' . . . END CLASSITEM "rnum" CLASS ## Use the RNUM value to color code the line strings randomly. STYLE COLOR 255 0 0 WIDTH 5 END EXPRESSION '1' END CLASS STYLE COLOR 0 255 0 WIDTH 5 END EXPRESSION '2' END CLASS STYLE COLOR 0 0 255 WIDTH 5 END EXPRESSION '3' END CLASS STYLE COLOR 255 255 0 WIDTH 5 END EXPRESSION '4' END CLASS NAME "Segments" STYLE COLOR 0 255 0 WIDTH 5 END END Thanks Bobb
_______________________________________________ mapserver-users mailing list mapserver-users@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/mapserver-users