ST_MaxM

定义

ST_MaxM 以几何对象为输入参数，返回其最大 m 坐标。

语法

sde.st_maxm (g1 sde.st_geometry)

返回类型

数值

如果 m 值不存在，则返回 NULL。

示例

Oracle

CREATE TABLE maxm_test (id integer, geometry sde.st_geometry);

INSERT INTO MAXM_TEST VALUES (
1901,
sde.st_polygon ('polygon zm((110 120 20 3, 110 140 22 3, 120 130 26 4, 110 120 20 3))', 0)
);

INSERT INTO MAXM_TEST VALUES (
1902,
sde.st_polygon ('polygon zm((0 0 40 7, 0 4 35 9, 5 4 32 12, 5 0 31 5, 0 0 40 7))', 0)
);

SELECT id, sde.st_maxm (geometry) Max_M
FROM MAXM_TEST;

        ID             MAX_M

      1901                 4
      1902                12

PostgreSQL

CREATE TABLE maxm_test (id integer, geometry sde.st_geometry);

INSERT INTO maxm_test VALUES (
1901,
sde.st_polygon ('polygon zm((110 120 20 3, 110 140 22 3, 120 130 26 4, 110 120 20 3))', 0)
);

INSERT INTO maxm_test VALUES (
1902,
sde.st_polygon ('polygon zm((0 0 40 7, 0 4 35 9, 5 4 32 12, 5 0 31 5, 0 0 40 7))', 0)
);

SELECT id, sde.st_maxm (geometry) 
AS Max_M
FROM maxm_test;

        id             max_m

      1901                 4
      1902                12