Oracle SQL to display results from dividing one variable with another - oracle

Question

I need to calculate the YTD weekly average for the GROSS_AMOUNT
In the below script, the first part of the code gets the number of weeks. The second part of the code gets the YTD sum for that same time period
How do I write the SQL so I can retrieve the actual value of YtdTotal/TotalWeeks?
SELECT YtdTotal/TotalWeeks FROM DUAL; does not work
-- STORES NUMBER OF WEEKS SINCE BEGINING OF YEAR INTO THE VARIABLE, TotalWeeks
DECLARE
TotalWeeks NUMBER;
BEGIN
SELECT to_number(to_char(sysdate, 'WW')) - to_number(to_char(trunc(sysdate, 'year'),'WW'))
INTO TotalWeeks
FROM DUAL
-- (retrieves number of weeks since beginning of year)
END
-- STORES THE SUM OF GROSS)AMOUNT FOR THE WEEKS CALCULATED ABOVE - INTO THE
DECLARE
VARIABLE, YtdTotal
BEGIN
SELECT SUM(GROSS_AMOUNT)
INTO YtdTotal
FROM PARENTS
WHERE process_date BETWEEN
(next_day(TRUNC(sysdate, 'year'),'SUN'))
AND
(next_day(TRUNC(sysdate),'SAT')-7);
END;

Answer 1

Don't use two separate anonymous PL/SQL blocks - combine them into one!
If you want to return the result, then - instead of an anonymous PL/SQL block - create a function.
CREATE OR REPLACE FUNCTION f_test
return NUMBER
IS
totalweeks NUMBER;
ytdtotal NUMBER;
result NUMBER;
BEGIN
-- STORES NUMBER OF WEEKS SINCE BEGINING OF YEAR INTO THE VARIABLE, TotalWeeks
SELECT TO_NUMBER (TO_CHAR (SYSDATE, 'WW'))
- TO_NUMBER (TO_CHAR (TRUNC (SYSDATE, 'year'), 'WW'))
INTO totalweeks
FROM DUAL;
-- (retrieves number of weeks since beginning of year)
-- STORES THE SUM OF GROSS)AMOUNT FOR THE WEEKS CALCULATED ABOVE - INTO THE
SELECT SUM (gross_amount)
INTO ytdtotal
FROM parents
WHERE process_date BETWEEN (NEXT_DAY (TRUNC (SYSDATE, 'year'), 'SUN'))
AND (NEXT_DAY (TRUNC (SYSDATE), 'SAT') - 7);
-- the final result
result := ytdtogal / totalweeks;
RETURN result;
END;
/
Use it as
select f_test from dual;