Not getting desired output

Question

declare
v_sys number ;
v_amt number ;
dt date;
cursor c is (select hcode,amt,EDATE,
dense_rank() over(order by hcode)x from a );
begin
v_sys :=1 ;
v_amt :=0 ;
for var in c loop
insert into b values(var.x,var.hcode);
if (v_sys = var.x ) then
v_amt := v_amt + var.amt ;
else
insert into c values(v_sys,v_amt,var.edate );
v_amt := var.amt ;
v_sys := var.x ;
dt:=var.edate;
end if ;
end loop;
insert into c values(v_sys,v_amt,dt );
end;..All is well with this code except it returns the value of table b as:
SQL> select * from b;
        ID      HCODE
         1         10
         1         10
         2         20
         2         20I need to get the output as:
SQL> select * from b;
        ID      HCODE
         1         10
         2         20Any idea?
Thanks

Answer 1

Well, hcode = 10 and hcode = 20 both appear twice in the cursor you are walking through. The first thing you do after fetching a record is INSERT INTO b. Since there are two records in the cursor for hcode = 10, you get two records in b.
I'm not entirely sure what you are trying to do here, but I suspect that you are rolling you own SUM for some reason. If so, then I think you need something more like:
DECLARE
   v_sys NUMBER;
   v_amt NUMBER;
   dt    DATE;
   CURSOR c IS
      SELECT hcode, amt, edate, DENSE_RANK() OVER(ORDER BY hcode) x
      FROM a;
BEGIN
   v_sys :=1;
   v_amt :=0;
   FOR var IN c LOOP
      IF (v_sys = var.x ) THEN
         v_amt := v_amt + var.amt;
      ELSE
         INSERT INTO c VALUES (v_sys, v_amt, var.edate);
         INSERT INTO b VALUES(var.x, var.hcode);
         v_amt := var.amt;
         v_sys := var.x;
         dt:=var.edate;
      END IF;
   END LOOP;
   INSERT INTO c values(v_sys,v_amt,dt );
END;John