ST_PointFromText function

The ST_PointFromText function takes a well-known text representation of a point and, optionally, a spatial reference system identifier as input parameters and returns the corresponding point.

If the given well-known text representation is null, then null is returned.

The recommended function for achieving the same result is the ST_Point function. It is recommended because of its flexibility: ST_Point takes additional forms of input as well as the well-known text representation.

Syntax

Parameters

wkt

A value of type CLOB(2G) that contains the well-known text representation of the resulting point.

srs_id

A value of type INTEGER that identifies the spatial reference system for the resulting point.

If the srs_id parameter is omitted, the spatial reference system with the numeric identifier 0 (zero) is used.

If srs_id does not identify a spatial reference system listed in the catalog view DB2GSE.ST_SPATIAL_REFERENCE_SYSTEMS, then an exception condition is raised (SQLSTATE 38SU1).

Return type

db2gse.ST_Point

Example

This example illustrates how ST_PointFromText can be used to create and insert a point from its well-known text representation. The record that is inserted has ID = 1110, and the geometry is a point in spatial reference system 1. The point is in the well-known text representation of a point. The X and Y coordinates for this geometry are: (10, 20).


SET CURRENT FUNCTION PATH = CURRENT FUNCTION PATH, db2gse
CREATE TABLE sample_points (id INTEGER, geometry ST_Point)

INSERT INTO sample_points
  VALUES (1110, ST_PointFromText ('point (30 40)', 1) )

The following SELECT statement returns the polygon that was recorded in the table:


SELECT id, CAST( ST_AsText( geometry ) AS VARCHAR(35) ) POINTS
  FROM sample_points
  WHERE id = 1110

Results:


ID         POINTS
---------- ---------------------------------------
      1110 POINTS ( 30.00000000 40.00000000)