Name
ST_NDims — Returns the coordinate dimension of a geometry.
Synopsis
integer ST_NDims(geometry g1);
Description
Returns the coordinate dimension of the geometry. PostGIS supports 2 - (x,y) , 3 - (x,y,z) or 2D with measure - x,y,m, and 4 - 3D with measure space x,y,z,m
This function supports 3d and will not drop the z-index.
Examples
Code
SELECT ST_NDims('POINT(1 1)') As d2point,
ST_NDims('POINT(1 1 2)') As d3point,
ST_NDims('POINTM(1 1 0.5)') As d2pointm;
Output
d2point | d3point | d2pointm
---------+---------+----------
2 | 3 | 3