ST_Disjoint

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。

提示:

在本查询中，可以使用 ST_Intersects 函数代替，只需将函数的结果等于 0，因为 ST_Intersects 和 ST_Disjoint 返回相反的结果。计算查询时，ST_Intersects 函数使用空间索引，而 ST_Disjoint 函数不使用。

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