Oracle
sde.st_convexhull (g1 sde.st_geometry)
PostgreSQL
st_convexhull (g1 st_geometry)
The example creates the sample_geometries table that has three columns: id, spatial_type, and geometry. The column spatial_type, a varchar(18), stores the name of the geometry subclass that is stored in the geometry column.
Oracle
CREATE TABLE sample_geometries (id integer, spatial_type varchar(18), geometry sde.st_geometry);
INSERT INTO sample_geometries (id, spatial_type, geometry) VALUES (
1,
'ST_LineString',
sde.st_linestring ('linestring (20 20, 30 30, 20 40, 30 50)', 0)
);
INSERT INTO sample_geometries (id, spatial_type, geometry) VALUES (
2,
'ST_Polygon',
sde.st_polygon ('polygon ((30 30, 25 35, 15 50, 35 80, 40 85, 80 90,70 75, 65 70, 55 50, 75 40, 60 30, 30 30))', 0)
);
INSERT INTO sample_geometries (id, spatial_type, geometry) VALUES (
3,
'ST_MultiPoint',
sde.st_multipoint ('multipoint (20 20, 30 30, 20 40, 30 50)', 0)
);
PostgreSQL
CREATE TABLE sample_geometries (id integer, spatial_type varchar(18), geometry st_geometry);
INSERT INTO sample_geometries (id, spatial_type, geometry) VALUES (
1,
'ST_LineString',
st_linestring ('linestring (20 20, 30 30, 20 40, 30 50)', 0)
);
INSERT INTO sample_geometries (id, spatial_type, geometry) VALUES (
2,
'ST_Polygon',
st_polygon ('polygon ((30 30, 25 35, 15 50, 35 80, 40 85, 80 90,70 75, 65 70, 55 50, 75 40, 60 30, 30 30))', 0)
);
INSERT INTO sample_geometries (id, spatial_type, geometry) VALUES (
3,
'ST_MultiPoint',
st_multipoint ('multipoint (20 20, 30 30, 20 40, 30 50)', 0)
);
The SELECT statement lists the subclass name stored in the spatial_type column and the convex hull of the geometry.
Oracle
SELECT id, spatial_type, sde.st_astext (sde.st_convexhull (geometry)) CONVEXHULL
FROM sample_geometries;
ID SPATIAL_TYPE CONVEXHULL
1 ST_LineString POLYGON ((20.00000000 40.00000000,
20.00000000 20.00000000, 30.00000000
30.00000000, 30.00000000 50.00000000,
20.00000000 40.00000000))
2 ST_Polygon POLYGON ((15.00000000 50.00000000,
25.00000000 35.00000000, 30.00000000
30.00000000, 60.00000000 30.00000000,
75.00000000 40.00000000, 80.00000000
90.00000000, 40.00000000 85.00000000,
35.00000000 80.00000000, 15.00000000
50.00000000))
3 ST_MultiPoint POLYGON ((20.00000000 40.00000000,
20.00000000 20.00000000, 30.00000000
30.00000000, 30.00000000 50.00000000,
20.00000000 40.00000000))
PostgreSQL
SELECT id, spatial_type, st_astext (st_convexhull (geometry)) AS CONVEXHULL
FROM sample_geometries;
id spatial_type convexhull
1 ST_LineString POLYGON ((20 40, 20 20, 30 30, 30 50,
20 40))
2 ST_Polygon POLYGON ((15 50, 25 35, 30 30, 60 30,
75 40, 80 90, 40 85, 35 80, 15 50))
3 ST_MultiPoint POLYGON ((20 40, 20 20, 30 30, 30 50,
20 40))
