ST_Z
Prev  7.4. Geometry Accessors  Next

Name

ST_Z — Returns the Z coordinate of 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.

[Note]

To get the minimum and maximum Z value of geometry coordinates use the functions ST_ZMin and ST_ZMax.

This method implements the SQL/MM specification.

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)