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 OpenGIS 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)

See Also

ST_GeomFromWKB, ST_LineFromWKB