Cursors & procedures - - Help in simple query!

Question

hi all...
i am having difficulties trying to implement a simple
PL/SQL program, in fact...
i got it working, but i believe it could be implemented
in a more procedural manner!!!
here is my working code:
CREATE VIEW Todays_Rank AS
Select ISBN, RANK()OVER (Order by Total_Sold ASC)Sales_Rank
FROM
(SELECT bk.ISBN, sum(cc.Quantity) Total_Sold
FROM Book bk, Cart_Contains cc, Shopping_Cart sc
WHERE bk.ISBN = cc.ISBN
AND cc.Cartid = sc.Cartid
AND ((sc.State='checked-out') Or (sc.State='fulfilled '))
Group by bk.ISBN
Order by sum(cc.Quantity) ASC);
SET serveroutput ON
BEGIN
DECLARE
CURSOR rank_cursor IS
SELECT ISBN, sales_rank FROM todays_rank;
IndRec rank_cursor%ROWTYPE;
BEGIN
OPEN rank_cursor;
LOOP
FETCH rank_cursor INTO IndRec;
EXIT WHEN rank_cursor%NOTFOUND;
UPDATE book bk
SET bk.sales_rank=IndRec.sales_rank
WHERE bk.isbn=IndRec.ISBN;
COMMIT;
END LOOP;
CLOSE rank_cursor;
END;
END;
as i understood from cursors so far, is that they do the same job as views, which made me think that there must be
a better implementation for the code above!!!
*note that the query above is meant to update the book
table directly, and after it is done, it deletes any
temporary values, i.e. the created views!!!
the part to deal with deleting the views is not
implemented yet though!!
i hope you have some hints for me...!!!
thanking your kind attention & cooperation in advance!!

Answer 1

hi all once again..
in relation to the same db schema brought up earlier,
a simple prog. has been implemented to run on daily basis,
checks all the books that has been ordered by the customers, and that applies on books that are in status
checked out, and compares the quantity of each ordered
book to the one held in stock!!
finally it generates a report of the ordered quantity by customers - quantity in stock * 5
the query is perfectly working as follow:
-- Retreival of quantity of books sold today
CREATE or replace VIEW sold_today AS
SELECT cc.ISBN, sum(cc.Quantity) AS total_sold
FROM Cart_Contains cc, Shopping_Cart shc
WHERE cc.Cartid = shc.Cartid
GROUP BY cc.ISBN
ORDER BY Sum(cc.quantity) DESC;
-- Retreival of the quantity in stock of each book
CREATE or replace VIEW stock_quantity AS
SELECT s.ISBN, sum(s.Quantity) AS total_stock
FROM stocks s
GROUP BY s.ISBN
ORDER BY Sum(s.quantity) DESC;
set serveroutput on
BEGIN
DECLARE
reOrder Number(4);
todaysDate SHOPPING_CART.ORDER_DATE%TYPE;
UnknownSoldType exception;
-- Combining outcome from the two views in a single cursor
cursor sold_cursor is
SELECT bk.ISBN, bk.Title, bk.Publisher_Name, st.total_sold, sq.total_stock, shc.Order_date
FROM sold_today st, stock_quantity sq, shopping_cart shc, cart_contains cc, book bk
WHERE bk.ISBN = st.ISBN
AND st.ISBN = sq.ISBN
AND sq.ISBN = cc.ISBN
AND cc.Cartid = shc.Cartid
AND (shc.State='checked-out');
IndRec sold_cursor%ROWTYPE;
BEGIN
-- Todays date
select distinct sysdate INTO todaysDate from dual;
-- Printing reoprt's headder
dbms_output.put_line('====================================='||'=========================================');
dbms_output.put_line('|| ISBN | Title | Publisher | QUANTIY | QUANTITY ||');
dbms_output.put_line('|| | | | ORDERS | PURCHASE ||');
OPEN sold_cursor;
LOOP
FETCH sold_cursor INTO IndRec;
EXIT WHEN sold_cursor%NOTFOUND;
-- Date checking vs. stock quantity
               IF to_char(IndRec.order_date, 'ddmmyyyy') = to_char(todaysDate, 'ddmmyyyy') THEN
                    IF IndRec.total_sold > IndRec.total_stock THEN
                    -- Printing orders' report content!
dbms_output.put_line('====================================='||'=========================================');
reOrder := (IndRec.total_sold - IndRec.total_stock)*5;
dbms_output.put_line(' || ' || Lpad(IndRec.ISBN,10,10) || ' | ' ||Lpad(IndRec.Title,20,20) || ' | ' || Lpad(IndRec.Publisher_Name,10,10 )||' | ' ||to_Char(IndRec.total_sold, '9999') || ' | ' || to_Char(reOrder, '9999')|| ' ||');
                    END IF;
               END IF;
          END LOOP;
          CLOSE sold_cursor;
     dbms_output.put_line('====================================='||'=========================================');
          EXCEPTION
          when UnknownSoldType then
               dbms_output.put_line('=======================');
               dbms_output.put_line('ERROR: Aborting program.');
               dbms_output.put_line('Unknown Pay Type for Name');
          when others then
               dbms_output.put_line('ERROR During Processing. See the DBA.');
END;
END;
but this raises up my previous question: what is the
alternative for views, if there is a better one!
another question, if views is the best alternative in this case, is it possible to delete the temporary
tables created by views in each case???
thanking and apprecuiating your help & attention...
cheers..
k.s.