Definition
ST_Aggr_Intersection returns a single geometry that is a union of the intersection of all input geometries.
Syntax
Oracle
sde.st_aggr_intersection (geometry1 sde.st_geometry)
SQLite
st_aggr_intersection (geometry1 geometryblob)
Return type
Oracle
ST_Geometry
SQLite
Geometryblob
Example
In this example, a biologist is trying to find the intersection of three wildlife habitats.
Oracle
First, create the table that stores the habitats.
CREATE TABLE habitats (
id integer not null,
shape sde.st_geometry
);
Next, insert the three polygons to the table.
INSERT INTO habitats (id, shape) VALUES (
1,
sde.st_polygon ('polygon ((5 5, 12 5, 12 10, 5 10, 5 5))', 4326)
);
INSERT INTO habitats (id, shape) VALUES (
2,
sde.st_polygon ('polygon ((10 8, 14 8, 14 15, 10 15, 10 8))', 4326)
);
INSERT INTO habitats (id, shape) VALUES (
3,
sde.st_polygon ('polygon ((6 8, 20 8, 20 20, 6 20, 6 8))', 4326)
);
Finally, select for the intersection of the habitats.
SELECT sde.st_astext(sde.st_aggr_intersection(shape)) AGGR_SHAPES
FROM habitats;
AGGR_SHAPES
POLYGON (( 10.00000000 8.00000000, 12.00000000 8.00000000, 12.00000000 10.00000000,
10.00000000 10.00000000, 10.00000000 8.00000000))
SQLite
First, create the table that stores the habitats.
CREATE TABLE habitats (
id integer primary key autoincrement not null
);
SELECT AddGeometryColumn(
NULL,
'habitats',
'shape',
4326,
'polygon',
'xy',
'null'
);
Next, insert the three polygons to the table.
INSERT INTO habitats (shape) VALUES (
st_polygon ('polygon ((5 5, 12 5, 12 10, 5 10, 5 5))', 4326)
);
INSERT INTO habitats (shape) VALUES (
st_polygon ('polygon ((10 8, 14 8, 14 15, 10 15, 10 8))', 4326)
);
INSERT INTO habitats (shape) VALUES (
st_polygon ('polygon ((6 8, 20 8, 20 20, 6 20, 6 8))', 4326)
);
Finally, select the intersection of the habitats.
SELECT st_astext(st_aggr_intersection(shape))
AS "AGGR_SHAPES"
FROM habitats;
AGGR_SHAPES
POLYGON (( 10.00000000 8.00000000, 12.00000000 8.00000000, 12.00000000 10.00000000,
10.00000000 10.00000000, 10.00000000 8.00000000))