Need help with report quering store procedure

Question

I posted earlier today with my code, but I thought I should start a new thread and explain my scenario properly. Sorry for that.
have to find if a person visited a particular type of store, lets say pets mart in last six months. Every time a member of us go to store, the transction is saved into a database, which means that there are 100s of records for each member. I have few condition to apply (like flags). For example, if a member visited pets mart in last 6 months, we can send him cuopan for that store.
In my last code, I was using count(*) which takes for ever as everytime function is been called, it checks everything and then return more then one row. And my scenario requires only a flag kind of stuff, like either that member visited a particular store or not.
I am not sure what approach would be the best and optimised, obviously not the count one. I tried the case statment and it also returns more then one record (for each visit of the member) and I am looking for something like if it occured then Y else N.
My old code was something like that
function fnc (memberno, startdate, endate) return number as abc number;
begin
select count(*) into abc
from table a, table b
where a.zz = b.cc
and a.shop_date between startdate and endate)
and a.store_shoped in ('st01' , 'sto02' , 'sto3')
and a.store_location in ('loc1' , 'loc2');
return (abc);
end fnc;
I really appreciate if you can suggest me a better way to handle my situation.
Could someome please help me?

Answer 1

Something involving WHERE EXISTS or add a ROWNUM = 1 filter:
function fnc (p_memberno in number, p_startdate in date, p_enddate in date)
  return number
as
  abc number;
begin
  select count(*)
    into abc
    from dual
   where exists (select null
                   from table a, table b
                  where a.zz = b.cc
                    and ?? = p_memberno
                    and a.shop_date between p_startdate and p_enddate
                    and a.store_shoped in ('st01' , 'sto02' , 'sto3')
                    and a.store_location in ('loc1' , 'loc2'));
  return (abc);
end fnc;With either approach, the count will return only 0 or 1 and will stop at the first match it finds.