ST_Dimension

定义

ST_Dimension 用于返回 ST_Geometry 对象的维度。

语法

sde.st_dimension (g1 sde.st_geometry)

返回类型

整型

示例

创建包含 geotype 和 g1 两列的 dimension_test 表。geotype 列存储的是 g1 几何列中所存储的子类的名称。

Oracle

CREATE TABLE dimension_test (geotype varchar(20), g1 sde.st_geometry);

INSERT INTO DIMENSION_TEST VALUES (
'Point',
sde.st_pointfromtext ('point (10.02 20.01)', 0)
);

INSERT INTO DIMENSION_TEST VALUES (
'Linestring',
sde.st_linefromtext ('linestring (10.02 20.01, 10.32 23.98, 11.92 25.64)', 0)
);

INSERT INTO DIMENSION_TEST VALUES (
'Polygon',
sde.st_polyfromtext ('polygon ((10.02 20.01, 11.92 35.64, 25.02 34.15, 19.15 33.94, 10.02 20.01))', 0)
);

INSERT INTO DIMENSION_TEST VALUES (
'Multipoint',
sde.st_mpointfromtext ('multipoint (10.02 20.01, 10.32 23.98, 11.92 25.64)', 0)
);

INSERT INTO DIMENSION_TEST VALUES (
'Multilinestring',
sde.st_mlinefromtext ('multilinestring ((10.02 20.01, 10.32 23.98, 11.92 25.64), (9.55 23.75, 15.36 30.11))', 0)
);

INSERT INTO DIMENSION_TEST VALUES (
'Multipolygon',
sde.st_mpolyfromtext ('multipolygon (((10.02 20.01, 11.92 35.64, 25.02 34.15,
19.15 33.94, 10.02 20.01), (51.71 21.73, 73.36 27.04, 71.52 32.87,
52.43 31.90, 51.71 21.73)))', 0)
);

PostgreSQL

CREATE TABLE dimension_test (geotype varchar(20), g1 sde.st_geometry);

INSERT INTO dimension_test VALUES (
'Point',
sde.st_point ('point (10.02 20.01)', 0)
);

INSERT INTO dimension_test VALUES (
'Linestring',
sde.st_linestring ('linestring (10.02 20.01, 10.32 23.98, 11.92 25.64)', 0)
);

INSERT INTO dimension_test VALUES (
'Polygon',
sde.st_polygon ('polygon ((10.02 20.01, 11.92 35.64, 25.02 34.15, 19.15 33.94, 10.02 20.01))', 0)
);

INSERT INTO dimension_test VALUES (
'Multipoint',
sde.st_multipoint ('multipoint (10.02 20.01, 10.32 23.98, 11.92 25.64)', 0)
);

INSERT INTO dimension_test VALUES (
'Multilinestring',
sde.st_multilinestring ('multilinestring ((10.02 20.01, 10.32 23.98, 11.92 25.64), (9.55 23.75, 15.36 30.11))', 0)
);

INSERT INTO dimension_test VALUES (
'Multipolygon',
sde.st_multipolygon ('multipolygon (((10.02 20.01, 11.92 35.64, 25.02 34.15,
19.15 33.94, 10.02 20.01), (51.71 21.73, 73.36 27.04, 71.52 32.87,
52.43 31.90, 51.71 21.73)))', 0)
);

SELECT 语句列出了 geotype 列中所存储的子类名称以及相应几何类型的维度。

Oracle

SELECT geotype, sde.st_dimension (g1) Dimension
FROM DIMENSION_TEST;

GEOTYPE                    Dimension

Point                       0
Linestring                  1
Polygon                     2
Multipoint                  0
Multilinestring             1
Multipolygon                2

PostgreSQL

SELECT geotype, sde.st_dimension (g1) 
AS Dimension
FROM dimension_test;

geotype                  dimension

Point                       0
Linestring                  1
Polygon                     2
Multipoint                  0
Multilinestring             1
Multipolygon                2