ST_CoordDim

定义

ST_CoordDim 返回 ST_Geometry 列的坐标值的维度。

语法

sde.st_coorddim (g1 sde.st_geometry)

返回类型

整型

2 = x,y 坐标

3 = x,y,z 或 x,y,m 坐标

4 = x,y,z,m 坐标

示例

创建包含 geotype 和 g1 两列的 coorddim_test 表。geotype 列存储 g1 ST_Geometry 列中所存储的几何子类的名称。

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

Oracle

INSERT INTO COORDDIM_TEST VALUES (
'Point',
sde.st_geometry ('point (60.567222 -140.404)', 0)
);

INSERT INTO COORDDIM_TEST VALUES (
'Point Z',
sde.st_geometry ('point Z (60.567222 -140.404 5959)', 0)
);

INSERT INTO COORDDIM_TEST VALUES (
'Point M',
sde.st_geometry ('point M (60.567222 -140.404 5250)', 0)
);

INSERT INTO COORDDIM_TEST VALUES (
'Point ZM',
sde.st_geometry ('point ZM (60.567222 -140.404 5959 5250)', 0)
);

PostgreSQL

INSERT INTO coorddim_test VALUES (
'Point',
st_point ('point (60.567222 -140.404)', 0)
);

INSERT INTO coorddim_test VALUES (
'Point Z',
st_point ('point z (60.567222 -140.404 5959)', 0)
);

INSERT INTO coorddim_test VALUES (
'Point M',
st_point ('point m (60.567222 -140.404 5250)', 0)
);

INSERT INTO coorddim_test VALUES (
'Point ZM',
st_point ('point zm (60.567222 -140.404 5959 5250)', 0)
);

SELECT 语句列出 geotype 列中所存储的子类名称以及相应几何的坐标维度。创建的所有要素都仅包含 x,y 坐标，所以 ST_CoordDim 返回 2。

Oracle

SELECT geotype, sde.st_coorddim (g1) coordinate_dimension
FROM COORDDIM_TEST;

GEOTYPE               coordinate_dimension

Point                           2
Point Z                         3
Point M                         3
Point ZM                        4

PostgreSQL

SELECT geotype, st_coorddim (g1) 
AS coordinate_dimension
FROM coorddim_test;

geotype              coordinate_dimension

Point                          2
Point Z                        3
Point M                        3
Point ZM                       4