ST_Dimension

Definition

ST_Dimension returns the dimension of a geometry object. In this case, dimension refers to length and width. For example, a point has neither length nor width, so its dimension is 0; whereas a line has length but no width, so its dimension is 1.

Syntax

Oracle and PostgreSQL

sde.st_dimension (geometry1 sde.st_geometry)

SQLite

st_dimension (geometry1 geometryblob)

Return type

Integer

Example

The dimension_test table is created with the columns geotype and g1. The geotype column stores the name of the subclass stored in the g1 geometry column.

The SELECT statement lists the subclass name stored in the geotype column with the dimension of that geotype.

Oracle

CREATE TABLE dimension_test (
 geotype varchar(20),
 g1 sde.st_geometry
);

INSERT INTO DIMENSION_TEST VALUES (
 'Point',
 sde.st_pointfromtext ('point (10.02 20.01)', 4326)
);

INSERT INTO DIMENSION_TEST VALUES (
 'Linestring',
 sde.st_linefromtext ('linestring (10.02 20.01, 10.32 23.98, 11.92 25.64)', 4326)
);

INSERT INTO DIMENSION_TEST VALUES (
 'Polygon',
 sde.st_polyfromtext ('polygon ((10.02 20.01, 11.92 35.64, 25.02 34.15, 19.15 33.94, 10.02 20.01))', 4326)
);

INSERT INTO DIMENSION_TEST VALUES (
 'Multipoint',
 sde.st_mpointfromtext ('multipoint (10.02 20.01, 10.32 23.98, 11.92 25.64)', 4326)
);

INSERT INTO DIMENSION_TEST VALUES (
 'Multilinestring',
 sde.st_mlinefromtext ('multilinestring ((10.02 20.01, 10.32 23.98, 11.92 25.64), (9.55 23.75, 15.36 30.11))', 4326)
);

INSERT INTO DIMENSION_TEST VALUES (
 'Multipolygon',
 sde.st_mpolyfromtext ('multipolygon (((10.02 20.01, 11.92 35.64, 25.02 34.15,
19.15 33.94, 10.02 20.01), (51.71 21.73, 73.36 27.04, 71.52 32.87,
52.43 31.90, 51.71 21.73)))', 4326)
);

SELECT geotype, sde.st_dimension (g1) Dimension
 FROM DIMENSION_TEST;

GEOTYPE                    Dimension

Point                       0
Linestring                  1
Polygon                     2
Multipoint                  0
Multilinestring             1
Multipolygon                2

PostgreSQL

CREATE TABLE dimension_test (
 geotype varchar(20),
 g1 sde.st_geometry
);

INSERT INTO dimension_test VALUES (
 'Point',
 sde.st_point ('point (10.02 20.01)', 4326)
);

INSERT INTO dimension_test VALUES (
 'Linestring',
 sde.st_linestring ('linestring (10.02 20.01, 10.32 23.98, 11.92 25.64)', 4326)
);

INSERT INTO dimension_test VALUES (
 'Polygon',
 sde.st_polygon ('polygon ((10.02 20.01, 11.92 35.64, 25.02 34.15, 19.15 33.94, 10.02 20.01))', 4326)
);

INSERT INTO dimension_test VALUES (
 'Multipoint',
 sde.st_multipoint ('multipoint (10.02 20.01, 10.32 23.98, 11.92 25.64)', 4326)
);

INSERT INTO dimension_test VALUES (
 'Multilinestring',
 sde.st_multilinestring ('multilinestring ((10.02 20.01, 10.32 23.98, 11.92 25.64), (9.55 23.75, 15.36 30.11))', 4326)
);

INSERT INTO dimension_test VALUES (
 'Multipolygon',
 sde.st_multipolygon ('multipolygon (((10.02 20.01, 11.92 35.64, 25.02 34.15,
19.15 33.94, 10.02 20.01), (51.71 21.73, 73.36 27.04, 71.52 32.87,
52.43 31.90, 51.71 21.73)))', 4326)
);

SELECT geotype, sde.st_dimension (g1) 
 AS Dimension
 FROM dimension_test;

geotype                  dimension

Point                       0
Linestring                  1
Polygon                     2
Multipoint                  0
Multilinestring             1
Multipolygon                2

SQLite

CREATE TABLE dimension_test (
 geotype varchar(20)
);

SELECT AddGeometryColumn (
 NULL,
 'dimension_test',
 'g1',
 4326,
 'geometry',
 'xy',
 'null'
);

INSERT INTO dimension_test VALUES (
 'Point',
 st_point ('point (10.02 20.01)', 4326)
);

INSERT INTO dimension_test VALUES (
 'Linestring',
 st_linestring ('linestring (10.02 20.01, 10.32 23.98, 11.92 25.64)', 4326)
);

INSERT INTO dimension_test VALUES (
 'Polygon',
 st_polygon ('polygon ((10.02 20.01, 11.92 35.64, 25.02 34.15, 19.15 33.94, 10.02 20.01))', 4326)
);

INSERT INTO dimension_test VALUES (
 'Multipoint',
 st_multipoint ('multipoint (10.02 20.01, 10.32 23.98, 11.92 25.64)', 4326)
);

INSERT INTO dimension_test VALUES (
 'Multilinestring',
 st_multilinestring ('multilinestring ((10.02 20.01, 10.32 23.98, 11.92 25.64), (9.55 23.75, 15.36 30.11))', 4326)
);

INSERT INTO dimension_test VALUES (
 'Multipolygon',
 st_multipolygon ('multipolygon (((10.02 20.01, 11.92 35.64, 25.02 34.15,
19.15 33.94, 10.02 20.01), (51.71 21.73, 73.36 27.04, 71.52 32.87,
52.43 31.90, 51.71 21.73)))', 4326)
);

SELECT geotype, st_dimension (g1) 
 AS "Dimension"
 FROM dimension_test;

geotype                  Dimension

Point                       0
Linestring                  1
Polygon                     2
Multipoint                  0
Multilines                  1
Multipolyg                  2