On 5-11-2011 12:00, venussoftop wrote:

>>> I know a qty. for a particular item purchased. This item though has been purchased over a long period only the last few purchase bills are now of concern (FIFO method). I have the following tables
>>>
>>> tPurchaseBill
>>> iID PK
>>> iNo Bill No.
>>> etc.
>>>
>>> sPurchaseBillItems
>>> iID PK
>>> iPID FK to tPurchaseBill table
>>> iItemID FK to mItems table
>>> bQty qty. in this purchase
>>> etc.
>>>
>>> so if I am to provide an iItemID and a bStock qty. can I bring out only those last few tPurchaseBill records. Is there any way I can do this in pure SQL?
>>
>> Sort by the purchase date descending and use the ROWS clause to limit
>> the amount of rows returned:
>> http://www.firebirdsql.org/file/documentation/reference_manuals/reference_material/html/langrefupd25-select.html#langrefupd25-select-rows
>>
>
> Thanks Mark for your response. Yes, I can limit the number of rows to something that is practical and not the whole set. But I do not think I will be able to convert the bStock qty. into number of rows as the qty. would be different in each purchase bill. Any suggestions on this front.

I think you will need to use EXECUTE BLOCK or a selectable PROCEDURE to
do that.

--
Mark Rotteveel