定义
ST_Disjoint 获取两个几何,如果两个几何的交集生成空集,则返回 1(Oracle 和 SQLite)或 t (PostgreSQL);否则返回 0(Oracle 和 SQLite)或 f (PostgreSQL)。
语法
Oracle 和 PostgreSQL
sde.st_disjoint (geometry1 sde.st_geometry, geometry2 sde.st_geometry)
SQLite
st_disjoint (geometry1 geometryblob, geometry2 geometryblob)
返回类型
布尔型
示例
在本例中,将创建两个表(distribution_areas 和 factories),并在每个表中插入值。接下来,将在 factories 和 st_disjoint 周围创建缓冲区,以便查找哪些工厂缓冲区没有跨越分布区域。
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