ST_WKBToSQL

ST_WKBToSQL takes a well-known binary representation of a geometry and returns the corresponding geometry. The spatial reference system with the identifier 0 (zero) is used for the resulting geometry.

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

Syntax

Parameter

wkb: A value of type BLOB(4M) that contains the well-known binary representation of the resulting geometry. If the well-known binary representation is null, null is returned.

Return type

db2gse.ST_Geometry

Example

This example illustrates use of the ST_WKBToSQL function. First, geometries are stored in the SAMPLE_GEOMETRIES table in its GEOMETRY column. Then, their well-known binary representations are stored in the WKB column using the ST_AsBinary function in the UPDATE statement. Finally, the ST_WKBToSQL function is used to return the coordinates of the geometries in the WKB column.


SET CURRENT PATH = CURRENT PATH, db2gse
CREATE TABLE sample_geometries
  (id INTEGER, geometry ST_Geometry, wkb BLOB(32K) )

INSERT INTO sample_geometries (id, geometry)
  VALUES (10, ST_Point ( 'point (44 14)', 0 ) ),
         (11, ST_Point ( 'point (24 13)', 0 ) ),
         (12, ST_Polygon ('polygon ((50 20, 50 40, 70 30, 50 20))', 0 ) )
UPDATE sample_geometries AS temp_correlated
  SET wkb = ST_AsBinary(geometry)
  WHERE id = temp_correlated.id

Use this SELECT statement to see the geometries in the WKB column.


SELECT id, CAST( ST_AsText( ST_WKBToSQL(wkb) ) AS VARCHAR(120) ) GEOMETRIES
  FROM sample_geometries

Results:


ID          GEOMETRIES
----------- -------------------------------------------------------------
         10 POINT ( 44.00000000 14.00000000)
         11 POINT ( 24.00000000 13.00000000)
         12 POLYGON (( 50.00000000 20.00000000, 70.00000000 30.00000000,
                       50.00000000 40.00000000, 50.00000000 20.00000000))