ST_Relate

定义

ST_Relate 比较两个几何，如果几何满足 DE-9IM 模式矩阵字符串指定的条件，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_relate (geometry1 sde.st_geometry, geometry2 sde.st_geometry, patternMatrix string)

SQLite

st_relate (geometry1 geometryblob, geometry2 geometryblob, patternMatrix string)

返回类型

布尔型

示例

DE-9IM 模式矩阵是一种用于比较几何的设备。此矩阵分为多种类型。例如，相等模式矩阵 (T*F**FFF*) 将告知您任意两几何是否相等。

本示例中，将创建包含三个空间列的表 relate_test，每个空间列中均插入了点要素。ST_Relate 函数用于在 SELECT 语句中测试各点是否相同。请注意，如果想要确定几何是否相等，则建议使用 ST_Equals 函数。

Oracle

CREATE TABLE relate_test (
 g1 sde.st_geometry,
 g2 sde.st_geometry,
 g3 sde.st_geometry
);

INSERT INTO relate_test (g1, g2, g3) VALUES (
 sde.st_geometry ('point (10.02 20.01)', 4326),
 sde.st_geometry ('point (10.02 20.01)', 4326),
 sde.st_geometry ('point (30.01 20.01)', 4326)
);

SELECT sde.st_relate (g1, g2, 'T*F**FFF*') g1_equals_g2, 
 sde.st_relate (g1, g3, 'T*F**FFF*') g1_equals_g3, 
 sde.st_relate (g2, g3, 'T*F**FFF*') g2_equals_g3 
 FROM RELATE_TEST;
 
g1_equals_g2     g1_equals_g3      g2_equals_g3

1                0                 0

PostgreSQL

CREATE TABLE relate_test (
 g1 sde.st_geometry,
 g2 sde.st_geometry,
 g3 sde.st_geometry
);

INSERT INTO relate_test (g1, g2, g3) VALUES (
 sde.st_geometry ('point (10.02 20.01)', 4326),
 sde.st_geometry ('point (10.02 20.01)', 4326),
 sde.st_geometry ('point (30.01 20.01)', 4326)
);

SELECT st_relate (g1, g2, 'T*F**FFF*') AS "g1=g2", 
 st_relate (g1, g3, 'T*F**FFF*') AS "g1=g3",
 st_relate (g2, g3, 'T*F**FFF*') AS "g2=g3" 
 FROM relate_test;
 
g1=g2     g1=g3     g2=g3

t          f         f

SQLite

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

SELECT AddGeometryColumn(
 NULL,
 'relate_test',
 'g1',
 4326,
 'point',
 'xy',
 'null'
);

CREATE TABLE relate_test2 (id integer primary key autoincrement not null);

SELECT AddGeometryColumn(
 NULL,
 'relate_test2',
 'g2',
 4326,
 'point',
 'xy',
 'null'
);

CREATE TABLE relate_test3 (id integer primary key autoincrement not null);

SELECT AddGeometryColumn(
 NULL,
 'relate_test3',
 'g3',
 4326,
 'point',
 'xy',
 'null'
);

INSERT INTO relate_test (g1) VALUES (
 st_geometry ('point (10.02 20.01)', 4326)
);

INSERT INTO relate_test2 (g2) VALUES (
 st_geometry ('point (10.02 20.01)', 4326)
);

INSERT INTO relate_test3 (g3) VALUES (
 st_geometry ('point (30.01 20.01)', 4326)
);

SELECT st_relate (relate_test.g1, relate_test2.g2, 'T*F**FFF*') AS "g1=g2", 
 st_relate (relate_test.g1, relate_test3.g3, 'T*F**FFF*') AS "g1=g3",
 st_relate (relate_test2.g2, relate_test3.g3, 'T*F**FFF*') AS "g2=g3" 
 FROM relate_test, relate_test2, relate_test3;
 
g1=g2     g1=g3     g2=g3

1          0         0