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