Help with function

I need some help with writing a plpgsql function. I want to return multiple
items from the function. How do I do this?

Here is my attempt at the function (note, this is a simple example that
could obviously be done via a view, but I am trying to learn more about
writing plpgsql functions):

create or replace function dba.active_transactions_by_db() returns setof
integer pg_stat_activity.datname%TYPE as
$BODY$
declare
dbName varchar;
activeTransactions integer;
countRec record;
begin
for countRec in select count(1) as cnt, datname from pg_stat_activity
group by datname loop
return next countRec;
end loop;

return countRec;
end;
$BODY$
language plpgsql;