TO SET

This function aggregates an input stream to a Set.

For example, you can aggregate a stream of persons to a Set<String> of the fullnames.

See Also
Operators
Expression Language
Defining and Managing Data Queries
Parameter Description
filterExpression An Apollo expression to keep some elements only. It is useful to process the aggregation on a subpart of your input stream.
expression An Apollo expression extracting the element to put into the Set. For example, person.fullname.