ST_Intersects

定义

如果两个几何的交集不生成空集，则 ST_Intersects 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_intersects (geometry1 sde.st_geometry, geometry2 sde.st_geometry)

SQLite

st_intersects (geometry1 geometryblob, geometry2 geometryblob)

返回类型

布尔型

示例

消防局局长想要获得在危险废弃物场地的某一半径范围内的敏感区域的列表。

敏感区域存储在 sensitive_areas 表中。定义为 polygon 的 shape 列存储每个敏感区域的轮廓。

危险场地存储在 hazardous_sites 表中。定义为 point 的 site 列存储表示每个危险场地的地理中心的位置。

SELECT 查询在每个危险场地周围创建缓冲半径区，并返回与危险场地缓冲区相交的敏感区域列表。

Oracle

--Create and populate tables.
CREATE TABLE sensitive_areas (
 id integer,
 shape sde.st_geometry
); 

CREATE TABLE hazardous_sites (
 id integer,
 site sde.st_geometry
);

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

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

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

INSERT INTO hazardous_sites VALUES (
 4,
 sde.st_geometry ('point (60 60)', 4326)
);

INSERT INTO hazardous_sites VALUES (
 5,
 sde.st_geometry ('point (30 30)', 4326)
);

--Create a buffer around the hazardous sites, then find the hazardous site buffers that intersect sensitive areas.
SELECT sa.id SA_ID, hs.id HS_ID
 FROM SENSITIVE_AREAS sa, HAZARDOUS_SITES hs
 WHERE sde.st_intersects (sde.st_buffer (hs.site, .1), sa.shape) = 1
 ORDER BY sa.id;

SA_ID      HS_ID

    1          5
    2          5
    3          4

PostgreSQL

--Create and populate tables.
CREATE TABLE sensitive_areas (
 id serial,
 shape sde.st_geometry
); 

CREATE TABLE hazardous_sites (
 id serial,
 site sde.st_geometry
);

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

INSERT INTO sensitive_areas (shape) VALUES (
 sde.st_geometry ('polygon ((30 30, 30 50, 50 50, 50 30, 30 30))', 4326)
);

INSERT INTO sensitive_areas (shape) VALUES (
 sde.st_geometry ('polygon ((40 40, 40 60, 60 60, 60 40, 40 40))', 4326)
);

INSERT INTO hazardous_sites (site) VALUES (
 sde.st_geometry ('point (60 60)', 4326)
);

INSERT INTO hazardous_sites (site) VALUES (
 sde.st_geometry ('point (30 30)', 4326)
);

--Create a buffer around the hazardous sites, then find the hazardous site buffers that intersect sensitive areas.
SELECT sa.id AS sid, hs.id AS hid
 FROM sensitive_areas sa, hazardous_sites hs
 WHERE sde.st_intersects (sde.st_buffer (hs.site, .1), sa.shape) = 't'
 ORDER BY sa.id;

sid     hid

  1       2
  2       2
  3       1

SQLite

--Create and populate tables.
CREATE TABLE sensitive_areas (
 id integer primary key autoincrement not null
); 

SELECT AddGeometryColumn (
 NULL,
 'sensitive_areas',
 'shape',
 4326,
 'polygon',
 'xy',
 'null'
);

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

SELECT AddGeometryColumn (
 NULL,
 'hazardous_sites',
 'site',
 4326,
 'point',
 'xy',
 'null'
);

INSERT INTO sensitive_areas (shape) VALUES (
 st_geometry ('polygon ((20 30, 30 30, 30 40, 20 40, 20 30))', 4326)
);

INSERT INTO sensitive_areas (shape) VALUES (
 st_geometry ('polygon ((30 30, 30 50, 50 50, 50 30, 30 30))', 4326)
);

INSERT INTO sensitive_areas (shape) VALUES (
 st_geometry ('polygon ((40 40, 40 60, 60 60, 60 40, 40 40))', 4326)
);

INSERT INTO hazardous_sites (site) VALUES (
 st_geometry ('point (60 60)', 4326)
);

INSERT INTO hazardous_sites (site) VALUES (
 st_geometry ('point (30 30)', 4326)
);

--Create a buffer around the hazardous sites, then find the hazardous site buffers that intersect sensitive areas.
SELECT sa.id AS "sid", hs.id AS "hid"
 FROM sensitive_areas sa, hazardous_sites hs
 WHERE st_intersects (st_buffer (hs.site, .1), sa.shape) = 1
 ORDER BY sa.id;

sid     hid

  1       2
  2       2
  3       1