ST_Disjoint

Definición

ST_Disjoint toma dos geometrías y devuelve 1 (Oracle y SQLite) o t (PostgreSQL) si la intersección de las dos geometrías produce un conjunto vacío; de lo contrario, devuelve 0 (Oracle y SQLite) o f (PostgreSQL).

Sintaxis

Oracle y PostgreSQL

sde.st_disjoint (geometry1 sde.st_geometry, geometry2 sde.st_geometry)

SQLite

st_disjoint (geometry1 geometryblob, geometry2 geometryblob)

Tipo de devolución

Booleano

Ejemplo

En este ejemplo, se crean dos tablas (distribution_areas y factories) y se insertan valores en cada una de ellas. A continuación, se crea una zona de influencia en torno a las fábricas y se usa st_disjoint para determinar qué zonas de influencia de fábricas no atraviesan las áreas de distribución.

Sugerencia:

Puede utilizar la función de ST_Intersects en su lugar en esta consulta al equiparar el resultado de la función a 0, porque ST_Intersects y ST_Disjoint devuelven resultados contrarios. La función de ST_Intersects utiliza el índice espacial al evaluar la consulta, mientras que la función ST_Disjoint no.

Oracle

--Create tables and insert values.
CREATE TABLE distribution_areas (
 id integer,
 areas sde.st_geometry
); 

CREATE TABLE factories (
 id integer,
 loc sde.st_geometry
); 

INSERT INTO distribution_areas (id, areas) VALUES (
 1,
 sde.st_geometry ('polygon ((20 30, 30 30, 30 40, 20 40, 20 30))', 4326)
);

INSERT INTO distribution_areas (id, areas) VALUES (
 2,
 sde.st_geometry ('polygon ((30 30, 30 50, 50 50, 50 30, 30 30))', 4326)
);

INSERT INTO distribution_areas (id, areas) VALUES (
 3,
 sde.st_geometry ('polygon ((40 40, 40 60, 60 60, 60 40, 40 40))', 4326)
);

INSERT INTO factories (id,loc) VALUES (
 4,
 sde.st_geometry ('point (60 60)', 4326)
);

INSERT INTO factories (id,loc) VALUES (
 5,
 sde.st_geometry ('point (30 30)', 4326)
);

--Buffer factories and find which buffers are separate from distribution areas. 
SELECT da.id
 FROM DISTRIBUTION_AREAS da, FACTORIES f
 WHERE sde.st_disjoint ((sde.st_buffer (f.loc, .001)), da.areas) = 1;

PostgreSQL

--Create tables and insert values.
CREATE TABLE distribution_areas (
 id serial,
 areas sde.st_geometry
); 

CREATE TABLE factories (
 id serial,
 loc sde.st_geometry
); 

INSERT INTO distribution_areas (areas) VALUES (
 sde.st_geometry ('polygon ((20 30, 30 30, 30 40, 20 40, 20 30))', 4326)
);

INSERT INTO distribution_areas (areas) VALUES (
 sde.st_geometry ('polygon ((30 30, 30 50, 50 50, 50 30, 30 30))', 4326)
);

INSERT INTO distribution_areas (areas) VALUES (
 sde.st_geometry ('polygon ((40 40, 40 60, 60 60, 60 40, 40 40))', 4326)
);

INSERT INTO factories (loc) VALUES (
 sde.st_geometry ('point (60 60)', 4326)
);

INSERT INTO factories (loc) VALUES (
 sde.st_geometry ('point (30 30)', 4326)
);

--Buffer factories and find which buffers are separate from distribution areas.
SELECT da.id
 FROM distribution_areas da, factories f
 WHERE sde.st_disjoint ((sde.st_buffer (f.loc, .001)), da.areas) = 't';

SQLite

--Create tables and insert values.
CREATE TABLE distribution_areas (
 id integer primary key autoincrement not null
); 

SELECT AddGeometryColumn (
 NULL,
 'distribution_areas',
 'areas',
 4326,
 'polygon',
 'xy',
 'null'
);

CREATE TABLE factories (
 id integer primary key autoincrement not null
); 

SELECT AddGeometryColumn (
 NULL,
 'factories',
 'loc',
 4326,
 'point',
 'xy',
 'null'
);

INSERT INTO distribution_areas (areas) VALUES (
 st_geometry ('polygon ((20 30, 30 30, 30 40, 20 40, 20 30))', 4326)
);

INSERT INTO distribution_areas (areas) VALUES (
 st_geometry ('polygon ((30 30, 30 50, 50 50, 50 30, 30 30))', 4326)
);

INSERT INTO distribution_areas (areas) VALUES (
 st_geometry ('polygon ((40 40, 40 60, 60 60, 60 40, 40 40))', 4326)
);

INSERT INTO factories (loc) VALUES (
 st_geometry ('point (60 60)', 4326)
);

INSERT INTO factories (loc) VALUES (
 st_geometry ('point (30 30)', 4326)
);

--Buffer factories and find which buffers are separate from distribution areas.
SELECT da.id
 FROM distribution_areas da, factories f
 WHERE st_disjoint ((st_buffer (f.loc, .001)), da.areas) = 1;

id

1
2
3