public function delete(){
		$this->validateFocus();
		$conditions	= $this->getConditionQuery( array() );
		$query	= 'DELETE FROM '.$this->getTableName().' WHERE '.$conditions;
#		$has	= $this->get( FALSE );
#		if( !$has )
#			throw new \InvalidArgumentException( 'Focused Indices are not existing.' );
		return $this->dbc->exec( $query );
	}