This is actually one of those places where I wonder if an answer-returning approach would be better or not. One interpretation:
ST_StartPoint(MultiLineString) -> MultiPoint Which implies ST_ExteriorRing(Multipolygon) -> MultiLineString All sorts of fun. Question is: is this an improvement... still requires handling the issues of N > 1, somehow or other. P. On Tue, Sep 25, 2012 at 2:08 PM, Paul Ramsey <pram...@opengeo.org> wrote: > When ST_NumGeometries == 1, you can run ST_StartPoint on > ST_GeometryN(geom,1). Where ST_NumGeometries > 1 you are in > "interpretation land". What's the start point of a geometry with two > lines? > > P. > > On Tue, Sep 25, 2012 at 1:38 PM, David Quinn <daithiqu...@gmail.com> wrote: >> As ST_StartPoint( multilinestring ) returns NULL for PostGIS 2.0 >> (http://postgis.refractions.net/docs/ST_StartPoint.html ), what >> approach can be used to identify the start and end points of a >> multilinestring? >> >> Thanks, >> David >> _______________________________________________ >> postgis-users mailing list >> postgis-users@postgis.refractions.net >> http://postgis.refractions.net/mailman/listinfo/postgis-users _______________________________________________ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
