SUM a COUNT function

Question

I need to perform a summation on the results of a COUNT but I'm not sure what's the best way to do it.
Example:
TableA
CaseID (int)
FollowupCorrespondence (int) incremented
CustomerName (varchar)
/**Get the total number of followups for each customer case, and display the customer's name.*/
select sum(count(FollowupCorrespondence)), CustomerName from
tableA
group by caseID, CustomerName;
This produces an error that the functions cannot be nested. How can I get the result that I'm looking for?

Answer 1

This?
SQL> with tablea as (
   select 1 caseid, 'John Doe' customername, 1 followupcorrespondence from dual union all
   select 1 caseid, 'John Doe', 2 from dual union all
   select 1 caseid, 'John Doe', 3 from dual union all
   select 1 caseid, 'John Doe', 4 from dual union all
   select 2 caseid, 'Jane Doe', 1 from dual union all
   select 2 caseid, 'Jane Doe', 2 from dual union all
   select 2 caseid, 'Jane Doe', 3 from dual)
select caseid,
   count(*) over (partition by caseid) cnt_caseid,
   customername,
   followupcorrespondence
from tablea
    CASEID CNT_CASEID CUSTOMER FOLLOWUPCORRESPONDENCE
         1          4 John Doe                      1
         1          4 John Doe                      2
         1          4 John Doe                      3
         1          4 John Doe                      4
         2          3 Jane Doe                      1
         2          3 Jane Doe                      2
         2          3 Jane Doe                      3