70 

    71 

    72 		### Dataset method: Order results by the specified +columns+.

    73 		###

    74 		def order_metadata( *columns )

    75 			columns.flatten!

    76 			ds = self

    77 			columns.each do |column|

    78 				if Thingfish::Metastore::PG::Metadata.metadata_columns.include?( column.to_sym )

    79 					ds = ds.order_append( column.to_sym )

    80 				else

    81 					ds = ds.order_append( self.user_metadata_expr(column) )

    82 				end

    83 			end

    84 

    85 			return ds

    86 		end

    87