ST_Dimension

Définition

ST_Dimension retourne la dimension d'un objet géométrie. Dans ce cas, la dimension se rapporte à la longueur et à la largeur. Par exemple, un point n'a ni longueur ni largeur et sa dimension est donc de 0, tandis qu'une ligne a une longueur mais pas de largeur et sa dimension est de 1.

Syntaxe

Oracle et PostgreSQL

sde.st_dimension (geometry1 sde.st_geometry)

SQLite

st_dimension (geometry1 geometryblob)

Type de retour

Entier

Exemple

La table dimension_test est créée avec les colonnes geotype et g1. La colonne geotype stocke le nom de la sous-classe stockée dans la colonne g1 geometry.

L'instruction SELECT ci-dessous liste le nom de la sous-classe stockée dans la colonne geotype avec la dimension du type de géométrie correspondant.

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