ST_MaxX

定义

ST_MaxX 以几何对象为输入参数，返回其最大 x 坐标。

语法

Oracle 和 PostgreSQL

sde.st_maxx (geometry1 sde.st_geometry)

SQLite

st_maxx (geometry1 geometryblob)

返回类型

Oracle 和 PostgreSQL

数值

SQLite

双精度型

示例

创建表 maxx_test，并向其中插入两个面。然后，使用 ST_MaxM 函数确定每个面的最大 x 值。

Oracle

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

INSERT INTO MAXX_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 MAXX_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_maxx (geometry) Max_X
 FROM MAXX_TEST;

        ID      MAX_X

      1901        120
      1902          5

PostgreSQL

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

INSERT INTO maxx_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 maxx_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_maxx (geometry)
 AS Max_X
 FROM maxx_test;

        id      max_x

      1901        120
      1902          5

SQLite

CREATE TABLE maxx_test (
 id integer
);

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

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

INSERT INTO maxx_test VALUES (
 1902,
 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, st_maxx (geometry)
 AS "max_x"
 FROM maxx_test;

id      max_x

1901    120.0
1902    5.00000000