ST_Boundary

Définition

ST_Boundary accepte une géométrie et retourne sa limite regroupée sous la forme d'un objet géométrie.

Syntaxe

Oracle et PostgreSQL

sde.st_boundary (geometry sde.st_geometry)

SQLite

st_boundary (geometry geometryblob)

Type de retour

Oracle et PostgreSQL

ST_Geometry

SQLite

Geometryblob

Exemple

Dans cet exemple, la table de limites est créée avec deux colonnes : type et geometry. Les instructions INSERT ci-dessous ajoutent un enregistrement pour chacune des géométries de sous-classe. La fonction ST_Boundary extrait la limite de chaque sous-classe stockée dans la colonne geometry. Notez que la géométrie résultante a toujours une dimension inférieure de un à celle de la géométrie en entrée. Les points et les multipoints résultent toujours en une limite qui est une géométrie vide, de dimension –1. Les objets linestring et multilinestring renvoient une limite multipoint, de dimension 0. Un objet polygon ou multipolygon renvoie toujours une limite multilinestring, de dimension 1.

Oracle

CREATE TABLE boundaries (
 geotype varchar(20),
 geometry sde.st_geometry
);

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

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

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

INSERT INTO BOUNDARIES 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))', 0)
);

INSERT INTO BOUNDARIES 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_astext (sde.st_boundary (geometry)) "The boundary"
 FROM BOUNDARIES;

GEOTYPE            The boundary

Point              POINT EMPTY
Linestring         MULTIPOINT(10.02000000 20.01000000, 11.92000000 25.64000000)
Polygon            MULTILINESTRING ((10.02000000 20.01000000, 19.15000000 33.94000000,25.02000000 34.15000000, 11.92000000 35.64000000, 10.02000000 20.01000000))
Multipoint         POINT EMPTY
Multilinestring    MULTIPOINT (9.55000000 23.75000000, 10.02000000 20.01000000, 11.92000000 25.64000000, 15.36000000 30.11000000)
Multipolygon       MULTILINESTRING((51.71000000 21.73000000, 73.36000000 27.04000000, 71.52000000 32.87000000, 52.43000000 31.90000000, 51.71000000 21.73000000), (10.02000000 20.01000000, 19.15000000 33.94000000, 25.02000000 34.15000000, 11.92000000 35.64000000, 10.02000000 20.01000000))

PostgreSQL

CREATE TABLE boundaries (
 geotype varchar(20),
 geometry st_geometry
);

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

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

INSERT INTO boundaries 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 boundaries VALUES (
'Multipoint',
st_multipoint ('multipoint (10.02 20.01, 10.32 23.98, 11.92 25.64)', 0)
);

INSERT INTO boundaries 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 boundaries 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_astext (st_boundary (geometry)) 
 AS "The boundary"
 FROM boundaries;

geotype            The boundary

Point              EMPTY
Linestring         MULTIPOINT(10.02000000 20.01000000, 11.92000000 25.64000000)
Polygon            LINESTRING ((10.02000000 20.01000000, 19.15000000 33.94000000,25.02000000 34.15000000, 11.92000000 35.64000000, 10.02000000
20.01000000))
Multipoint         EMPTY
Multilinestring    MULTIPOINT (9.55000000 23.75000000, 10.02000000 20.01000000, 11.92000000 25.64000000, 15.36000000 30.11000000)
Multipolygon       MULTILINESTRING((51.71000000 21.73000000, 73.36000000 27.04000000, 71.52000000 32.87000000, 52.43000000 31.90000000,
51.71000000 21.73000000), (10.02000000 20.01000000, 19.15000000 33.94000000, 25.02000000 34.15000000, 11.92000000 35.64000000, 
10.02000000 20.01000000))

SQLite

CREATE TABLE boundaries (
 geotype varchar(20)
);

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

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

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

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

INSERT INTO boundaries 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 boundaries 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_astext (st_boundary (geometry)) 
 FROM boundaries;

Point              EMPTY
Linestring         MULTIPOINT(10.02000000 20.01000000, 11.92000000 25.64000000)
Polygon            LINESTRING ((10.02000000 20.01000000, 19.15000000 33.94000000,25.02000000 34.15000000, 11.92000000 35.64000000, 10.02000000
20.01000000))
Multipoint         EMPTY
Multilinestring    MULTIPOINT (9.55000000 23.75000000, 10.02000000 20.01000000, 11.92000000 25.64000000, 15.36000000 30.11000000)
Multipolygon       MULTILINESTRING((51.71000000 21.73000000, 73.36000000 27.04000000, 71.52000000 32.87000000, 52.43000000 31.90000000,
51.71000000 21.73000000), (10.02000000 20.01000000, 19.15000000 33.94000000, 25.02000000 34.15000000, 11.92000000 35.64000000, 
10.02000000 20.01000000))