ST_PointFromWKB

Definition

ST_PointFromWKB takes a well-known binary (WKB) representation and a spatial reference ID to return an ST_Point.

Syntax

Oracle

PostgreSQL

Oracle

sde.st_pointfromwkb (wkb blob, srid integer)

PostgreSQL

sde.st_pointfromwkb (wkb bytea, srid integer)

SQLite

st_pointfromwkb (wkb blob, srid int32)

Return type

ST_Point

Example

This example illustrates how ST_PointFromWKB can be used to create a point from its well-known binary representation. The geometries are points in spatial reference system 4326. In this example, the points are stored in the geometry column of the sample_points table, then the wkb column is updated with their well-known binary representations (using the ST_AsBinary function). Finally, the ST_PointFromWKB function is used to return the points from the WKB column. The sample-points table has a geometry column, where the points are stored, and a wkb column, where the points' well-known binary representations are stored.

In the SELECT statement, the ST_PointFromWKB function is used to retrieve the points from the WKB column.

Oracle

CREATE TABLE sample_points (
 id integer,
 geometry sde.st_point,
 wkb blob
);

INSERT INTO SAMPLE_POINTS (id, geometry) VALUES (
 10,
 sde.st_point ('point (44 14)', 4326)
);

INSERT INTO SAMPLE_POINTS (id, geometry) VALUES (
 11,
 sde.st_point ('point (24 13)', 4326)
);

UPDATE SAMPLE_POINTS
 SET wkb = sde.st_asbinary (geometry)
 WHERE id = 10;

UPDATE SAMPLE_POINTS
 SET wkb = sde.st_asbinary (geometry)
 WHERE id = 11;
SELECT id, sde.st_astext (sde.st_pointfromwkb(wkb, 4326)) POINTS
 FROM SAMPLE_POINTS;

ID POINTS

10 POINT (44.00000000 14.00000000) 
11 POINT (24.00000000 13.00000000)

PostgreSQL

CREATE TABLE sample_points (
 id integer,
 geometry sde.st_point,
 wkb bytea
);

INSERT INTO sample_points (id, geometry) VALUES (
 10,
 sde.st_point ('point (44 14)', 4326)
);

INSERT INTO sample_points (id, geometry) VALUES (
 11,
 sde.st_point ('point (24 13)', 4326)
);

UPDATE sample_points
 SET wkb = sde.st_asbinary (geometry)
 WHERE id = 10;

UPDATE sample_points
 SET wkb = sde.st_asbinary (geometry)
 WHERE id = 11;
SELECT id, sde.st_astext (sde.st_pointfromwkb(wkb, 4326)) 
 AS points
 FROM sample_points;

id points

10 POINT (44 14) 
11 POINT (24 13)

SQLite

CREATE TABLE sample_pts (
 id integer,
 wkb blob
);

SELECT AddGeometryColumn(
 NULL,
 'sample_pts',
 'geometry',
 4326,
 'point',
 'xy',
 'null'
);

INSERT INTO sample_pts (id, geometry) VALUES (
 10,
 st_point ('point (44 14)', 4326)
);

INSERT INTO sample_pts (id, geometry) VALUES (
 11,
 st_point ('point (24 13)', 4326)
);

UPDATE sample_pts
 SET wkb = st_asbinary (geometry)
 WHERE id = 10;

UPDATE sample_pts
 SET wkb = st_asbinary (geometry)
 WHERE id = 11;
SELECT id, st_astext (st_pointfromwkb(wkb, 4326)) 
 AS "points"
 FROM sample_pts;

id points

10 POINT (44.00000000 14.00000000) 
11 POINT (24.00000000 13.00000000)

Related Topics

6/19/2015