Displaying the values from a single column into two columns???

Question

hi buddies.....I've a table "Stock" and its fields are:
Date, Invoice#, prod_id, sal_qty, pur_qty, rate, status
The "rate" column stores the rate value on which a product was sold or purchased and "status" column values are like "S" for Sale,"OP" for opening and "P" for purchase.
The problem here to me is that I'm unable to pick the purchase & sale rate of a product based on the status either "S" or "P". Is it possible to pick the purchase rate of a product sold between a specified limit of dates??? and show both sale & purchase rates in two separate columns in the result sets for a given product in a specified duration. The resulte set format should be like this:
Prod_id Sale_Rate Pur_Rate

Answer 1

Dear Dmitri,
Let me tell u my case more elaborately so that u can have a better insight on my problem. I've a Stock table to which I'm trying to use to calculate current stock quantity, its value and profit per sale transaction. It has following simple description.
Stock_Table:
Invoice#     Date     Product     Batch# Sale_QTY     Pur_QTY     Rate Status
Pur-001     01/01/05     Asprin          AB123      0     100           10 OP --(Opening)
Pur-002 02/01/05     Paracetamol CD456          0     150          15 OP
Pur-002 03/01/05     Menthol XY333           0     80          7     OP
Pur-003     01/01/05     Asprin          ZZ990           0     50          8     P ..(Purchase)
Sale001 02/01/05     Asprin          AB123           10     0          2     S
Sale001 02/01/05     Paracetamol      CD456           5     0          16     S ..(Sale)
Sale002 04/01/05     Asprin          ZZ990           6     0          10     S
Sale002 04/01/05     Paracetamol      CD456           7     0          20     S
Sale002 04/01/05     Menthol      XY333          4     0          10     S
From this design can u calulate the difference of sale & purchase rate of a product during a range of dates(which is the Profit)? i.e firstly pick a sale transaction and then minus the purchase rate of the product from the sale rate in that sale transaction by looking at the product name and its batch number.
While solving this case, please keep in mind that I'm using Oracle 8.0 which doesn't support inlined Sub-Query(a query within FROM clause). So giving u a hint(although I'm not genious enough;), I tried the Self Join at Stock Table by picking the sale rows at first and then purchase rows afterwords by giving this table two different names. I also tried the following query by joining the Sale Table with Stock Table. Is it the right way I'm heading towards???
SELECT S.Sale_Date, SD.Invoice#, SD.Product, SD.QTY, SD.Rate Sale_Rate,
ST.Rate Pur_Rate, ST.Product
FROM Invoice_Master S, Invoice_Detail SD, Stock ST
WHERE S.Invoice# = SD.Invoice#
AND ST.Status IN('OP','P')
AND ST.Product = SD.Product
AND S.Sale_Date BETWEEN :From_Date AND :To_Date
AND SD.Product = P.Product
ORDER BY S.Sale_Date