SQL> desc stk;
 Name                                                                  Type
 ----------------------------------------- -------- ------------------------------------
 ITEM                                                             VARCHAR2(20)
 PRICE                                                            NUMBER(10,2)
 MONTH                                                        NUMBER(2)
 YEAR                                                            NUMBER(4)
 OPENING                                                     NUMBER(10)
 PRODUCTION                                             NUMBER(10)
 SALE                                                             NUMBER(20)

SQL> select * from stk;

ITEM       PRICE      MONTH       YEAR        OPENING   PRODUCTION      SALE
---------   ---------       ----------       ----------      ----------            ----------             ----------
Doll         500                12                2007             100                300                     375
Doll         500                11                2007                0                 100                        0

SQL> desc sale;
 Name                                                                   Type
 ----------------------------------------------------- -------- ------------------------------------
 BILL_NO                                                        NUMBER(5)
 BILL_DATE                                                   DATE
 ITEM                                                              VARCHAR2(20)
 PRICE                                                             NUMBER(10)
 QTY                                                                NUMBER(10)

SQL> select * from sale;

   BILL_NO          BILL_DATE        ITEM                      PRICE        QTY
----------                ---------            --------------------          ----------   ----------
         1                10-DEC-07              Doll                            300         75
         2                15-DEC-07              Doll                            400        125
         3                17-DEC-07              Doll                            300         50
         4               18-DEC-07               Doll                            400         75
         5               18-DEC-07               Doll                            300         25
         6               20-DEC-07               Doll                            500         25

6 rows selected.

SQL>  select a.item as item,a.price as price,nvl(b.opening,0) as opening,
  2   nvl(b.production,0) as production,a.sale as sale,
  3   ((nvl(b.opening,0)+nvl(b.production,0)-a.sale)) as closing
  4   from (select item,price,sum(qty) as sale from sale
  5   where bill_date between '1-dec-07' and '31-dec-07'
  6   group by item,price)a,
  7   (select item,price,opening,production
  8   from stk where month=12 and year=2007)b
  9   where a.item=b.item(+)
 10   and a.price=b.price(+);

ITEM                   PRICE    OPENING    PRODUCTION       SALE    CLOSING
-------------------- ----------         ----------       ----------             ----------    ----------
Doll                        300               0                   0                          150       -150
Doll                        400               0                   0                          200       -200
Doll                        500              100              300                          25        375



Look at query result where closing is in minus figure,due to this I want to split opening and 
Production in such a way that  it come zero and remaining opening,production and closing must come in the row which has unit price same as in stk e.g 500.