ST_Envelope
Definition
ST_Envelope gibt das kleinste umgebende Rechteck eines ST_Geometry-Objekts als Polygon zurück.
Hinweis:Diese Funktion entspricht der Simple Features-Spezifikation von Open Geospatial Consortium, Inc. (OGC), die besagt, dass ST_Envelope ein Polygon zurückgibt. Bei der Arbeit mit Sonderfällen von Punktgeometrien oder horizontalen und vertikalen Linien gibt die Funktion ST_Envelope ein Polygon zurück, das diese Formen eine Einheit ober- und unterhalb der minimalen und maximalen X- und Y-Koordinaten umschließt.
Syntax
sde.st_envelope (g1 sde.st_geometry)
Rückgabetyp
ST_Geometry
Beispiel
In der Spalte "geotype" der Tabelle "envelope_test" wird der Name der Geometrie-Subclass gespeichert, die in der Spalte "g1" vom Typ ST_Geometry enthalten ist.
CREATE TABLE envelope_test (geotype varchar(20), g1 sde.st_geometry);
Mit der INSERT-Anweisung wird jede Geometrie-Subclass in die Tabelle "envelope_test" eingefügt.
Oracle
INSERT INTO ENVELOPE_TEST VALUES (
'Point',
sde.st_geometry ('point (10.02 20.01)', 0)
);
INSERT INTO ENVELOPE_TEST VALUES (
'Linestring',
sde.st_geometry ('linestring (10.01 20.01, 10.01 30.01, 10.01 40.01)', 0)
);
INSERT INTO ENVELOPE_TEST VALUES (
'Linestring',
sde.st_geometry ('linestring (10.02 20.01, 10.32 23.98, 11.92 25.64)', 0)
);
INSERT INTO ENVELOPE_TEST VALUES (
'Polygon',
sde.st_geometry ('polygon ((10.02 20.01, 11.92 35.64, 25.02 34.15, 19.15 33.94, 10.02 20.01))', 0)
);
INSERT INTO ENVELOPE_TEST VALUES (
'Multipoint',
sde.st_geometry ('multipoint (10.02 20.01, 10.32 23.98, 11.92 25.64)', 0)
);
INSERT INTO ENVELOPE_TEST VALUES (
'Multilinestring',
sde.st_geometry ('multilinestring ((10.01 20.01, 20.01 20.01, 30.01 20.01), (30.01 20.01, 40.01 20.01, 50.01 20.01))', 0)
);
INSERT INTO ENVELOPE_TEST VALUES (
'Multilinestring',
sde.st_geometry ('multilinestring ((10.02 20.01, 10.32 23.98, 11.92 25.64), (9.55 23.75, 15.36 30.11))', 0)
);
INSERT INTO ENVELOPE_TEST VALUES (
'Multipolygon',
sde.st_geometry ('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)))', 0)
);
PostgreSQL
INSERT INTO envelope_test VALUES (
'Point',
sde.st_point ('point (10.02 20.01)', 0)
);
INSERT INTO envelope_test VALUES (
'Linestring',
sde.st_linestring ('linestring (10.01 20.01, 10.01 30.01, 10.01 40.01)', 0)
);
INSERT INTO envelope_test VALUES (
'Linestring',
sde.st_linestring ('linestring (10.02 20.01, 10.32 23.98, 11.92 25.64)', 0)
);
INSERT INTO envelope_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))', 0)
);
INSERT INTO envelope_test VALUES (
'Multipoint',
sde.st_multipoint ('multipoint (10.02 20.01, 10.32 23.98, 11.92 25.64)', 0)
);
INSERT INTO envelope_test VALUES (
'Multilinestring',
sde.st_multilinestring ('multilinestring ((10.01 20.01, 20.01 20.01, 30.01 20.01), (30.01 20.01, 40.01 20.01, 50.01 20.01))', 0)
);
INSERT INTO envelope_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))', 0)
);
INSERT INTO envelope_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)))', 0)
);
Die Abfrage listet den Subclass-Namen und den zugehörigen Envelope auf. Die Funktion ST_Envelope gibt den Envelope zurück, der einen Punkt, eine Linie oder ein Polygon umschließt.
Oracle
SELECT geotype, sde.st_astext (sde.st_envelope (g1)) Envelope FROM ENVELOPE_TEST; GEOTYPE Envelope Point POLYGON (( 9.02000000 19.01000000, 11.02000000 19.01000000, 11.02000000 21.01000000, 9.02000000 21.01000000, 9.02000000 19.01000000)) Linestring POLYGON (( 9.01000000 19.01000000, 11.01000000 19.01000000, 11.01000000 41.01000000, 9.01000000 41.01000000, 9.01000000 19.01000000)) Linestring POLYGON (( 10.02000000 20.01000000, 11.92000000 20.01000000, 11.92000000 25.64000000, 10.02000000 25.64000000, 10.02000000 20.01000000)) Polygon POLYGON (( 10.02000000 20.01000000, 25.02000000 20.01000000, 25.02000000 35.64000000, 10.02000000 35.64000000, 10.02000000 20.01000000)) Multipoint POLYGON (( 10.02000000 20.01000000, 11.92000000 20.01000000, 11.92000000 25.64000000, 10.02000000 25.64000000, 10.02000000 20.01000000)) Multilinestring POLYGON (( 9.01000000 19.01000000, 51.01000000 19.01000000, 51.01000000 21.01000000, 9.01000000 21.01000000, 9.01000000 19.01000000)) Multilinestring POLYGON (( 9.55000000 20.01000000, 15.36000000 20.01000000, 15.36000000 30.11000000, 9.55000000 30.11000000, 9.55000000 20.01000000)) Multipolygon POLYGON (( 10.02000000 20.01000000, 73.36000000 20.01000000, 73.36000000 35.64000000, 10.02000000 35.64000000, 10.02000000 20.01000000))
PostgreSQL
SELECT geotype, sde.st_astext (sde.st_envelope (g1)) AS Envelope FROM envelope_test; geotype envelope Point | POLYGON (( 9.02000000 19.01000000, 11.02000000 19.01000000, 11.02000000 21.01000000, 9.02000000 21.01000000, 9.02000000 19.01000000)) Linestring | POLYGON (( 9.01000000 19.01000000, 11.01000000 19.01000000, 11.01000000 41.01000000, 9.01000000 41.01000000, 9.01000000 19.01000000)) Linestring | POLYGON (( 10.02000000 20.01000000, 11.92000000 20.01000000, 11.92000000 25.64000000, 10.02000000 25.64000000, 10.02000000 20.01000000)) Polygon | POLYGON (( 10.02000000 20.01000000, 25.02000000 20.01000000, 25.02000000 35.64000000, 10.02000000 35.64000000, 10.02000000 20.01000000)) Multipoint | POLYGON (( 10.02000000 20.01000000, 11.92000000 20.01000000, 11.92000000 25.64000000, 10.02000000 25.64000000, 10.02000000 20.01000000)) Multilinestring | POLYGON (( 9.01000000 19.01000000, 51.01000000 19.01000000, 51.01000000 21.01000000, 9.01000000 21.01000000, 9.01000000 19.01000000)) Multilinestring | POLYGON (( 9.55000000 20.01000000, 15.36000000 20.01000000, 15.36000000 30.11000000, 9.55000000 30.11000000, 9.55000000 20.01000000)) Multipolygon | POLYGON (( 10.02000000 20.01000000, 73.36000000 20.01000000, 73.36000000 35.64000000, 10.02000000 35.64000000, 10.02000000 20.01000000))
7/10/2012