public function setDbConnection( $dbc ){
		if( !is_object( $dbc ) )
			throw new \InvalidArgumentException( 'Database connection resource must be an object' );
		if( !is_a( $dbc, 'PDO' ) )
			throw new \InvalidArgumentException( 'Database connection resource must be a direct or inherited PDO object' );
		$this->dbc = $dbc;
	}