ST_MaxY

定义

ST_MaxY 以几何对象为输入参数，返回其最大 y 坐标。

语法

Oracle 和 PostgreSQL

sde.st_maxy (geometry1 sde.st_geometry)

SQLite

st_maxy (geometry1 geometryblob)

返回类型

Oracle 和 PostgreSQL

数值

SQLite

双精度型

示例

创建表 maxy_test，并向其中插入两个面。然后，使用 ST_MaxY 函数确定每个面的最大 y 值。

Oracle

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

INSERT INTO MAXY_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 MAXY_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_maxy (geometry) Max_Y
 FROM MAXY_TEST;

        ID      MAX_Y

      1901        140
      1902          4

PostgreSQL

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

INSERT INTO maxy_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 maxy_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_maxy (geometry) 
 AS Max_Y
 FROM maxy_test;

        id      max_y

      1901        140
      1902          4

SQLite

CREATE TABLE maxy_test (
 id integer
);

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

INSERT INTO maxy_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 maxy_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_maxy (geometry) 
 AS "max_y"
 FROM maxy_test;

id      max_y

1901    140.0
1902    4.00000000