ST_Is3D
Signature
INT ST_Is3D(GEOMETRY geom);Description
Returns 1 if a geom has at least one z-coordinate; 0 otherwise.
Examples
-- No z-coordinates
SELECT ST_Is3D('LINESTRING(1 1, 2 1, 2 2, 1 2, 1 1)'::GEOMETRY);
-- Answer: 0
-- One z-coordinate
SELECT ST_Is3D('LINESTRING(1 1 1, 2 1, 2 2, 1 2, 1 1)'::GEOMETRY);
-- Answer: 1
-- All z-coordinates
SELECT ST_Is3D('LINESTRING(1 1 1, 2 1 2, 2 2 3,
1 2 4, 1 1 5)'::GEOMETRY);
-- Answer: 1