PL/SQL Function Syntax help please...

Question

Can someone help me with the syntax here please? I am sure i am doing something wrong in my LOOP.
create or replace FUNCTION fcn_chk_dec(p_date number)
return NUMBER
as
--DECLARE
v_date NUMBER;
v_active NUMBER;
v_prev NUMBER;
v_delta NUMBER;
v_perc_delta NUMBER:
CURSOR c_prev_active IS
     select date,people,
lag(people,1) over (order by date)
     from stats
where date between to_date(p_date, 'YYYYMMDD')-2 and to_date(p_date, 'YYYYMMDD')-1
     order by date desc
BEGIN
     OPEN c_prev;
loop
     FETCH c_prev INTO v_date,v_active,v_prev;
     exit when c_prev%NOTFOUND;
     v_delta:=v_active-v_prev;
v_perc_delta:=trunc((v_delta/v_active*100),2)
end loop;
close c_prev;
return v_perc_delta;
END fcn_chk_dec;

Answer 1

what i am trying to do is create a funtion that will return one value for the first row that comes back.
here is my initial query. the reason i did not go with this query is because there are too many selects and i was told that's not good and slows down the system. Plus, i need to have a function call in another program that will access this function to compare it's output to a value in a table.
here was my initial start:
select date,people,delta,trunc((delta/people*100),2) as perc_delta
from (select date, people,people-prev_dly_people as delta
from
(select date,people,
lag(people,1) over (order by date) as prev_dly_people
from stats
where date between to_char(sysdate-2,'YYYYMMDD') and to_char(sysdate-1,'YYYYMMDD')
order by date desc))
basically, i have a table that has a total number of people. I want to get the percentage growth and decline from the most recent date and the date before it. This will give me a day to day percentage of people population change as of the most recent date.
I need this to be a function becaus i want to be able to pass any date i want into it and get the given delta percentage at the time for the people's population.
hope this makes sense.