ST_MaxZ

Definition

ST_MaxZ takes a geometry as an input parameter and returns its maximum z-coordinate.

Syntax

Oracle and PostgreSQL

sde.st_maxz (geometry1 sde.st_geometry)

SQLite

st_maxz (geometry1 geometryblob)

Return type

Oracle and PostgreSQL

Number

If no z values are present, NULL is returned.

SQLite

Double precision

If no z values are present, NULL is returned.

Example

In the following example, table maxz_test is created and two polygons inserted to it. ST_MaxZ is then run to return the maximum z-value for each polygon.

Oracle

CREATE TABLE maxz_test (
 id integer,
 geometry sde.st_geometry
);

INSERT INTO MAXZ_TEST VALUES (
 1901,
 sde.st_polygon ('polygon zm((110 120 20 3, 110 140 22 3, 120 130 26 4, 110 120 20 3))', 4326)
);

INSERT INTO MAXZ_TEST VALUES (
 1902,
 sde.st_polygon ('polygon zm((0 0 40 7, 0 4 35 9, 5 4 32 12, 5 0 31 5, 0 0 40 7))', 4326)
);

SELECT id, sde.st_maxz (geometry) Max_Z
 FROM MAXZ_TEST;

        ID      MAX_Z

      1901         26
      1902         40

PostgreSQL

CREATE TABLE maxz_test (
 id integer,
 geometry sde.st_geometry
);

INSERT INTO maxz_test VALUES (
 1901,
 sde.st_polygon ('polygon zm((110 120 20 3, 110 140 22 3, 120 130 26 4, 110 120 20 3))', 4326)
);

INSERT INTO maxz_test VALUES (
 1902,
 sde.st_polygon ('polygon zm((0 0 40 7, 0 4 35 9, 5 4 32 12, 5 0 31 5, 0 0 40 7))', 4326)
);

SELECT id, sde.st_maxz (geometry) 
 AS Max_Z
 FROM maxz_test;

        id      max_z

      1901         26
      1902         40

SQLite

CREATE TABLE maxz_test (
 id integer
);

SELECT AddGeometryColumn (
 NULL,
 'maxz_test',
 'geometry',
 4326,
 'polygonzm',
 'xyzm',
 'null'
);

INSERT INTO maxz_test VALUES (
 1901,
 st_polygon ('polygon zm((110 120 20 3, 110 140 22 3, 120 130 26 4, 110 120 20 3))', 4326)
);

INSERT INTO maxz_test VALUES (
 1902,
 st_polygon ('polygon zm((0 0 40 7, 0 4 35 9, 5 4 32 12, 5 0 31 5, 0 0 40 7))', 4326)
);

SELECT id AS "ID", st_maxz (geometry) AS "Max Z"
 FROM maxz_test;

ID      Max Z

1901    26.0
1902    40.0

Related Topics

6/19/2015