ST_MinX

定义

ST_MinX 以几何对象为输入参数，返回其最小 x 坐标。

语法

Oracle 和 PostgreSQL

sde.st_minx (geometry1 sde.st_geometry)

SQLite

st_minx (geometry1 geometryblob)

返回类型

Oracle 和 PostgreSQL

数值

SQLite

双精度型

示例

创建表 minx_test，并向其中插入两个面。然后运行 ST_MinX，以确定每个面的最小 x 坐标值。

Oracle

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

INSERT INTO MINX_TEST VALUES (
 1901,
 sde.st_polygon ('polygon zm((110 120 20 3, 110 140 22 3, 120 130 26 4, 110 120 20 3))', 4326)
);

INSERT INTO MINX_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))', 4326)
);

SELECT id, sde.st_minx (geometry) MinX
 FROM MINX_TEST;

        ID       MINX

      1901        110
      1902          0

PostgreSQL

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

INSERT INTO minx_test VALUES (
 1901,
 sde.st_polygon ('polygon zm((110 120 20 3, 110 140 22 3, 120 130 26 4, 110 120 20 3))', 4326)
);

INSERT INTO minx_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))', 4326)
);

SELECT id, sde.st_minx (geometry) 
 AS MinX
 FROM minx_test;

        id       minx

      1901        110
      1902          0

SQLite

CREATE TABLE minx_test (
 id integer
);

SELECT AddGeometryColumn (
 NULL,
 'minx_test',
 'geometry',
 4326,
 'polygonzm',
 'xyzm',
 'null'
);

INSERT INTO minx_test VALUES (
 1914,
 st_polygon ('polygon zm((110 120 20 3, 110 140 22 3, 120 130 26 4, 110 120 20 3))', 4326)
);

INSERT INTO minx_test VALUES (
 1915,
 st_polygon ('polygon zm((0 0 40 7, 0 4 35 9, 5 4 32 12, 5 0 31 5, 0 0 40 7))', 4326)
);

SELECT id AS "ID", st_minx (geometry) AS "MinX"
 FROM minx_test;

ID       MinX

1914     110.0
1915       0.0