Name
ST_Z — Return the Z coordinate of the point, or NULL if not
available. Input must be a point.
Synopsis
float ST_Z(
geometry a_point)
;
Description
Return the Z coordinate of the point, or NULL if not
available. Input must be a point.
This method implements the SQL/MM specification:
SQL-MM 3 standard New Spec: ?
This function supports 3d and will not drop the z-index.
Examples
SELECT ST_Z(ST_GeomFromEWKT('POINT(1 2 3 4)'));
st_z
------
3
(1 row)