Sum (query directive)
From WandoraWiki
Description
Returns the sum of values of active column.
Constructor
Sum(Directive directive)
Examples
Following example sums the number of instances of each instances.
importPackage(org.wandora.query2); new Sum( new Count(new Instances()) .from(new Instances()) )
Note that you can do the same thing easier without the Sum.
importPackage(org.wandora.query2); new Count(new Instances().from(new Instances()))