ST_Envelope
Definition
ST_Envelope returns the minimum bounding box of an ST_Geometry object as a polygon.
メモ: This function conforms with the OGC Simple Features specification that states that ST_Envelope return a polygon. To work with special cases of point geometries or horizontal or vertical lines, the ST_Envelope function returns polygon around these shapes that are one unit above and below the max x and y and minx and y coordinates.
Syntax
sde.st_envelope (g1 sde.st_geometry)
Return type
ST_Geometry
Example
The envelope_test table's geotype column stores the name of the geometry subclass stored in the g1 ST_Geometry column.
CREATE TABLE envelope_test (geotype varchar(20), g1 sde.st_geometry);
The INSERT statements insert each geometry subclass into the envelope_test table.
Oracle
INSERT INTO ENVELOPE_TEST VALUES (
'Point',
sde.st_pointfromtext ('point (10.02 20.01)', 0)
);
INSERT INTO ENVELOPE_TEST VALUES (
'Linestring',
sde.st_linefromtext ('linestring (10.01 20.01, 10.01 30.01, 10.01 40.01)', 0)
);
INSERT INTO ENVELOPE_TEST VALUES (
'Linestring',
sde.st_linefromtext ('linestring (10.02 20.01, 10.32 23.98, 11.92 25.64)', 0)
);
INSERT INTO ENVELOPE_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))', 0)
);
INSERT INTO ENVELOPE_TEST VALUES (
'Multipoint',
sde.st_mpointfromtext ('multipoint (10.02 20.01, 10.32 23.98, 11.92 25.64)', 0)
);
INSERT INTO ENVELOPE_TEST VALUES (
'Multilinestring',
sde.st_mlinefromtext ('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_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 ENVELOPE_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)))', 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)
);
The query lists the subclass name and its envelope. The ST_Envelope function returns the envelope around a point, line, or polygon.
Oracle
SELECT geotype, sde.st_astext (sde.st_envelope (g1)) Envelope FROM ENVELOPE_TEST; GEOTYPE Envelope Point POLYGON (( 9.02000000 9.02000000, 21.01000000 9.02000000, 21.01000000 21.01000000, 9.02000000 21.01000000, 9.02000000 9.02000000)) 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 10.02000000, 11.92000000 20.01000000, 11.92000000 25.64000000, 10.02000000 25.64000000, 10.02000000 10.02000000)) 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 9.02000000, 21.01000000 9.02000000, 21.01000000 21.01000000, 9.02000000 21.01000000, 9.02000000 9.02000000)) 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 10.02000000, 11.92000000 20.01000000, 11.92000000 25.64000000, 10.02000000 25.64000000, 10.02000000 10.02000000)) 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))
3/6/2012