ST_IsMeasured

定义

ST_IsMeasured 以几何对象作为输入参数，如果给定几何具有测量值，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_ismeasured (geometry1 sde.st_geometry)

SQLite

st_ismeasured (geometry1 geometryblob)

返回类型

布尔型

示例

创建表 ism_test，并向其中插入值；然后确定 ism_test 表中哪些行包含测量值。

Oracle

CREATE TABLE ism_test (
 id integer,
 geom sde.st_geometry
);

INSERT INTO ISM_TEST VALUES (
 19,
 sde.st_geometry ('polygon ((40 120, 90 120, 90 150, 40 150, 40 120))', 4326)
);

INSERT INTO ISM_TEST VALUES (
 20,
 sde.st_geometry ('multipoint m(10 10 5, 50 10 6, 10 30 8)' , 4326)
);

INSERT INTO ISM_TEST VALUES (
 21,
 sde.st_geometry ('linestring z(10 10 166, 20 10 168)', 4326)
);

INSERT INTO ISM_TEST VALUES (
 22, 
 sde.st_geometry ('point zm(10 10 16 30)', 4326)
);

SELECT id, sde.st_ismeasured (geom) M_values
 FROM ISM_TEST;

      ID    M_values

      19          0
      20          1
      21          0
      22          1

PostgreSQL

CREATE TABLE ism_test (
 id integer,
 geom sde.st_geometry
);

INSERT INTO ISM_TEST VALUES (
 19,
 sde.st_geometry ('polygon ((40 120, 90 120, 90 150, 40 150, 40 120))', 4326)
);

INSERT INTO ISM_TEST VALUES (
 20,
 sde.st_geometry ('multipoint m(10 10 5, 50 10 6, 10 30 8)' , 4326)
);

INSERT INTO ISM_TEST VALUES (
 21,
 sde.st_geometry ('linestring z(10 10 166, 20 10 168)', 4326)
);

INSERT INTO ISM_TEST VALUES (
 22, 
 sde.st_geometry ('point zm(10 10 16 30)', 4326)
);

SELECT id, sde.st_ismeasured (geom) 
  AS has_measures
  FROM ism_test;

      id   has_measures

      19          f
      20          t
      21          f
      22          t

SQLite

CREATE TABLE ism_test (
 id integer
);

SELECT AddGeometryColumn (
 NULL,
 'ism_test',
 'geom',
 4326,
 'geometryzm',
 'xyzm',
 'null'
);

INSERT INTO ISM_TEST VALUES (
 19,
 st_geometry ('polygon ((40 120, 90 120, 90 150, 40 150, 40 120))', 4326)
);

INSERT INTO ISM_TEST VALUES (
 20,
 st_geometry ('multipoint m(10 10 5, 50 10 6, 10 30 8)' , 4326)
);

INSERT INTO ISM_TEST VALUES (
 21,
 st_geometry ('linestring z(10 10 166, 20 10 168)', 4326)
);

INSERT INTO ISM_TEST VALUES (
 22, 
 st_geometry ('point zm(10 10 16 30)', 4326)
);

SELECT id, st_ismeasured (geom)
 AS "M_values"
 FROM ism_test;

        ID    M_values

      19          0
      20          1
      21          0
      22          1