# Relational ranking use cases

This example uses ranking to return only the 5 tallest pupils:

    		DataSelection query = buildClassroomDataSelection();

    		//get all the result items
    		List resultItems = query.getResultItems();
    		//we asked for height to be the fourth result item/column, so we won't check:
    		DataItem height = (DataItem) resultItems.get(3);

    		//create a ranking step filter which returns the top 5 heights:
    		DataItemRankFilter top5Step = new DataItemRankFilter(DataItemRankFilter.TOP, 5, true);
    		height.addStep(top5Step);

    		//execute the query

The result is: