How get Required Number of Records

Question

I have to Tables stk_tble and pur_tble
stk_tble containts current stock balance and pur_tble contains purchase detail
select item_code,net_qty from  stk_tble
where item_code='BS-1034W'
ITEM_CODE              NET_QTY
BS-1034W                     1
select item_code,doc_no,txn_dt,qty from  pur_tble
where item_code='BS-1034W' order by txn_dt desc
ITEM_CODE            DOC_NO               TXN_DT          QTY
BS-1034W             14217                23-APR-12         3
BS-1034W             13696                16-MAY-10        30I want to develop a query or a cursor or a loop.That will exit when sum(purchase_qty)>=Stock qty
Suppose in the above example BALANCE Is 1 so
the Query will show me
ITEM_CODE            DOC_NO               TXN_DT          QTY
BS-1034W             14217                23-APR-12         3If BALANCE is suppose 10 then it will show me
ITEM_CODE            DOC_NO               TXN_DT          QTY
BS-1034W             14217                23-APR-12         3
BS-1034W             13696                16-MAY-10        30As balance of both of Transaction >=10 i.e. our balance qty

Answer 1

You didn't mention your forms-version.
Option 1:
Loop over the records in a cursor-loop and exit the loop when the quantity is reached.
Option 2:
Use the analytical option SUM() OVER (ORDER BY ..) to do it in one query.