PostGIS
Synopsis
geometry +`*`+ST_GeomFromWKB*(`bytea `geom`)`;
geometry +`*`+ST_GeomFromWKB*(`bytea `geom, integer
srid`)`;
Description
The ST_PointFromWKB function, takes a well-known binary
representation of geometry and a Spatial Reference System ID (SRID)
and creates an instance of the appropriate geometry type - in this case,
a POINT geometry. This function plays the role of the Geometry
Factory in SQL.
If an SRID is not specified, it defaults to 0. NULL is returned if
the input bytea does not represent a POINT geometry.
This method
implements the OGC Simple
Features Implementation Specification for SQL 1.1. s3.2.7.2
This method
implements the SQL/MM specification. SQL-MM 3: 6.1.9
This function
supports 3d and will not drop the z-index.
This method
supports Circular Strings and Curves
Examples
SELECT
ST_AsText(
ST_PointFromWKB(
ST_AsEWKB('POINT(2 5)'::geometry)
)
);
st_astext
------------
POINT(2 5)
(1 row)
SELECT
ST_AsText(
ST_PointFromWKB(
ST_AsEWKB('LINESTRING(2 5, 2 6)'::geometry)
)
);
st_astext
-----------
(1 row)