ST_EndPoint

定义

ST_EndPoint 返回线串的最后一个点。

语法

Oracle 和 PostgreSQL

sde.st_endpoint (line1 sde.st_geometry)

SQLite

st_endpoint (line1 geometryblob)

返回类型

ST_Point

示例

endpoint_test 表存储唯一标识各行的 gid integer 列和存储线串的 ln1 ST_LineString 列。

INSERT 语句将线串插入 endpoint_test 表中。第一个线串没有 z 坐标或测量值，而第二个线串有。

查询将列出 gid 列和 ST_EndPoint 函数所生成的 ST_Point 几何。

Oracle

--Create table and insert values.
CREATE TABLE endpoint_test (
 gid integer,
 ln1 sde.st_geometry
);

INSERT INTO ENDPOINT_TEST VALUES (
 1,
 sde.st_linefromtext ('linestring (10.02 20.01, 23.73 21.92, 30.10 40.23)', 4326)
);

INSERT INTO ENDPOINT_TEST VALUES (
 2,
 sde.st_linefromtext ('linestring zm(10.02 20.01 5.0 7.0, 23.73 21.92 6.5 7.1,30.10 40.23 6.9 7.2)', 4326)
);

--Find the end point of each line.
SELECT gid, sde.st_astext (sde.st_endpoint (ln1)) Endpoint
 FROM ENDPOINT_TEST;

GID         Endpoint                       

 1    POINT (30.10 40.23)
 2    POINT ZM (30.10 40.23 6.9 7.2)

PostgreSQL

--Create table and insert values.
CREATE TABLE endpoint_test (
 gid integer,
 ln1 sde.st_geometry
);

INSERT INTO endpoint_test VALUES (
 1,
st_linestring ('linestring (10.02 20.01, 23.73 21.92, 30.10 40.23)', 4326)
);

INSERT INTO endpoint_test VALUES (
 2,
 st_linestring ('linestring zm(10.02 20.01 5.0 7.0, 23.73 21.92 6.5 7.1,30.10 40.23 6.9 7.2)', 4326)
);

--Find the end point of each line.
SELECT gid, st_astext (st_endpoint (ln1)) 
 AS endpoint
 FROM endpoint_test;

gid          endpoint                       

 1    POINT (30.10 40.23)
 2    POINT ZM (30.10 40.23 6.9 7.2)

SQLite

--Create table, add geometry column, and insert values.
CREATE TABLE endpoint_test (
 gid integer primary key autoincrement not null
);

SELECT AddGeometryColumn (
 NULL,
 'endpoint_test',
 'ln1',
 4326,
 'linestringzm',
 'xyzm',
 'null'
);

INSERT INTO endpoint_test (ln1) VALUES (
 st_linestring ('linestring (10.02 20.01, 23.73 21.92, 30.10 40.23)', 4326)
);

INSERT INTO endpoint_test (ln1) VALUES (
 st_linestring ('linestring zm(10.02 20.01 5.0 7.0, 23.73 21.92 6.5 7.1,30.10 40.23 6.9 7.2)', 4326)
);

--Find the end point of each line.
SELECT gid, st_astext (st_endpoint (ln1)) 
 AS "endpoint"
 FROM endpoint_test;

gid          endpoint                       

 1    POINT (30.10000000 40.23000000)
 2    POINT ZM (30.10000000 40.23000000 6.90000000 7.20000000)