Group by problem with count

Question

I am trying to figure out the number of charters taken by each customer. I can get it to work fine if I just count the trip id and group by the last name. The problem is that I want to display my customer's full names and keep getting errors when I try to group by the concatenated field Any suggestions? Here is the code I am using:
Select count(charter.char_trip)"Total Charters",
CUS_FNAME||' '||CUS_LNAME "Customer"
From CHARTER, CUSTOMER
WHERE CUSTOMER.CUS_CODE = CHARTER.CUS_CODE
Group by "Customer"
;

Answer 1

try using a subquery.
  select cc.customer "Customer",
         count(cc.char_trip) "Total Charters"
    from (select charter.char_trip,
                 CUS_FNAME||' '||CUS_LNAME
            From CHARTER, CUSTOMER
           where CUSTOMER.CUS_CODE = CHARTER.CUS_CODE) cc
  group by cc.customernote: untested