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