NSPredicate something equivalent of SQL's GROUP BY

To simplify: There are 3 columns in a table named cards.

id packTitle term

id is a column - integers from 0.....100

packTitle - string describing packs, lets say there are 3 kinds of pack PACK1, PACK2, PACK3

term - different unsorted names of 101 items.

by SQL statement

select packTitle from cards group by packTitle;

I can get list of 3 items.

Could you suggest NSPredicate equivalent of SQL statement GROUP BY. I need to get an array to populate in UITableView.