I'm no expert but the third dimension appears to be supported by most types and the docs are pretty good about showing this. Take a point for example:
http://postgis.refractions.net/docs/ST_MakePoint.html You can add a third argument to add the z coordinate. Use ST_Y(point) to access the third dimension. Oh, and when you add your geometry column, be sure to specify a dimension of 3. http://postgis.refractions.net/docs/AddGeometryColumn.html hth charles On May 19, 2010, at 6:27 AM, 孙琦 wrote: > Hi experts, > > Do we have a way to resolve the third dimensionality of GEOMETRY data? As > known, those single types(POINT, LINESTRING, POLYGON....) all have the > corresponding XYM versions with suffix M. Thus, if we have > three-dimensionality feature, we can discriminate its third dimensionality as > Z or M by the returned geometry type. However, if the mixed-typed (GEOMETRY) > is used, it seems that it's hard to resolve the 3rd dimensionality. By the > Postgis 1.5.1 manual, no GEOMETRYM type is provided to fix the issue. So can > someone tell me if there is another way to do the work? > > Thanks, > Cheney > _______________________________________________ > 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
