Definition
ST_Boundary ein wählt eine Geometrie aus und gibt dessen kombinierte Grenze als Geometrieobjekt zurück.
Syntax
Oracle und PostgreSQL
sde.st_boundary (geometry sde.st_geometry)
SQLite
st_boundary (geometry geometryblob)
Rückgabetyp
Oracle und PostgreSQL
ST_Geometry
SQLite
Geometryblob
Beispiel
In diesem Beispiel wird die Tabelle "boundaries" mit den zwei Spalten erstellt: "type" und "geometry". Die nachfolgenden INSERT-Anweisungen fügen jeder Subclass-Geometrie einen Datensatz hinzu. Die Funktion ST_Boundary dient zum Abrufen der Grenze jeder Subclass, die in der Spalte "geometry" gespeichert ist. Beachten Sie, dass die Dimension der resultierenden Geometrie immer um eins kleiner als die Eingabegeometrie ist. Punkte und Multipoints resultieren stets in einer Grenze, die eine leere Geometrie ist, Dimension –1. Linestrings und Multilinestrings geben eine Multipoint-Grenze zurück, Dimension 0. Ein Polygon oder Multipolygon gibt stets eine Multilinestring-Grenze zurück, 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))