code: public synchronized Blob getBlob(int parameterIndex) throws SQLException {
  
          Object o = getObject(parameterIndex);
  
          if (o == null) {
              return null;
          }
  
          if (o instanceof BlobDataID) {
              return new JDBCBlobClient(session, (BlobDataID) o);
          }
  
          throw Util.sqlException(ErrorCode.X_42561);
      }
docs: <!-- start generic documentation -->
  
  Retrieves the value of the designated JDBC <code>BLOB</code> parameter as a
  {@link java.sql.Blob} object in the Java programming language.
  
  <!-- end generic documentation -->
  
  <!-- start release-specific documentation -->
  <div class="ReleaseSpecificDocumentation">
  <h3>HSQLDB-Specific Information:</h3> <p>
  
  HSQLDB supports this feature. <p>
  
  </div>
  <!-- end release-specific documentation -->
  
  @param parameterIndex the first parameter is 1, the second is 2,
  and so on
  @return the parameter value as a <code>Blob</code> object in the
  Java programming language.  If the value was SQL <code>NULL</code>, the value
  <code>null</code> is returned.
  @exception SQLException if a database access error occurs or
  this method is called on a closed <code>CallableStatement</code>
  @exception SQLFeatureNotSupportedException if the JDBC driver does not support
  this method
  @since JDK 1.2 (JDK 1.1.x developers: read the overview for
  JDBCParameterMetaData)