SDO_UTIL.VALIDATE_WKBGEOMETRY

Format

SDO_UTIL.VALIDATE_WKBGEOMETRY(
     geometry  IN BLOB 
     ) RETURN VARCHAR2;

Description

Validates the input geometry, which is in the standard well-known binary (WKB or EWKB) format; returns the string TRUE if the input is valid, or FALSE if the input is not valid WKB or EWKB.

Parameters

geometry: Geometry in WKB or EWKB format to be checked for validity.

Usage Notes

Note:

The SDO_UTIL.VALIDATE_WKBGEOMETRY function is supported only if Oracle JVM is enabled on your Oracle Autonomous Database Serverless deployments. To enable Oracle JVM, see Use Oracle Java in Using Oracle Autonomous Database Serverless for more information.

To be valid, the input geometry may be in the well-known binary (WKB) format, or in the EWKB format.

This function is patterned after the SQL Multimedia recommendations in ISO 13249-3, Information technology - Database languages - SQL Multimedia and Application Packages - Part 3: Spatial.

To validate a geometry in the well-known text (WKT) format, use the SDO_UTIL.VALIDATE_WKTGEOMETRY function.

Examples

The following example shows conversion to and from WKB and WKT format, and validation of WKB and WKT geometries. (The example uses the definitions and data from Simple Example: Inserting_ Indexing_ and Querying Spatial Data, specifically the cola_b geometry from the COLA_MARKETS table.)

DECLARE
  wkbgeom BLOB;
  wktgeom CLOB;
  val_result VARCHAR2(5);
  geom_result SDO_GEOMETRY;
  geom SDO_GEOMETRY;
BEGIN
SELECT c.shape INTO geom FROM cola_markets c WHERE c.name = 'cola_b';
 
-- To WBT/WKT geometry
wkbgeom := SDO_UTIL.TO_WKBGEOMETRY(geom);
wktgeom := SDO_UTIL.TO_WKTGEOMETRY(geom);
DBMS_OUTPUT.PUT_LINE('To WKT geometry result = ' || TO_CHAR(wktgeom));
 
-- From WBT/WKT geometry
geom_result := SDO_UTIL.FROM_WKBGEOMETRY(wkbgeom);
geom_result := SDO_UTIL.FROM_WKTGEOMETRY(wktgeom);
 
-- Validate WBT/WKT geometry
val_result := SDO_UTIL.VALIDATE_WKBGEOMETRY(wkbgeom);
DBMS_OUTPUT.PUT_LINE('WKB validation result = ' || val_result);
val_result := SDO_UTIL.VALIDATE_WKTGEOMETRY(wktgeom);
DBMS_OUTPUT.PUT_LINE('WKT validation result = ' || val_result);
 
END;/
 
To WKT geometry result = POLYGON ((5.0 1.0, 8.0 1.0, 8.0 6.0, 5.0 7.0, 5.0 1.0))
WKB validation result = TRUE                                                    
WKT validation result = TRUE

35.88 SDO_UTIL.VALIDATE_WKBGEOMETRY