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 -1. 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