>Dear Sir/Madam
>
>I have a purchase List Table Eg.
>

>ArrivalDate Qty Rate Total Value
>22-May-10 2999.984 $805.00 $24,29,568.53
>20-Apr-10 1250.000 $819.00 $10,27,140.30
>11-Apr-10 170.000 $800.00 $1,36,000.00
>11-Apr-10 1500.277 $800.00 $12,04,398.61
>08-Apr-10 1334.341 $800.00 $10,70,842.95
>08-Apr-10 1500.000 $810.00 $12,18,802.06
>03-Apr-10 500.000 $790.00 $3,96,212.85
>03-Apr-10 2499.664 $790.00 $19,80,622.10
>29-Mar-10 700.000 $805.00 $5,64,989.05
>08-Feb-10 1499.912 $768.00 $11,58,486.82
>08-Feb-10 1500.000 $787.00 $11,80,500.00
>

>
>I need a query if user input 5000 then
>
>Result should be ($24,29,568.53 + $10,27,140.30 + $1,36,000.00 ) + (581 (Balance amount) * 800)= 464800
>
>So Total amount is 4057508.83
>
>If we divide the above amount by 5000 I get Avg pur rate of my unsold Stock (811.5) .
>
>My table is Sorted desc
>
>Even if more than one Query is required please help me to solve it.


1) I have a table with Purchase information Date of Purchase, Qty Purchased , and Rate

2) Now lets say I have 5000 MT in Stock

3) I need purchase average price for 5000 MT

4) So I will take the latest purchase first which is 2999.984 and mulitply it by 805.
then 1250 * 819 and add it to previous total and keep a record of Qty running total
and continue till my qty total reached 5000 MT

5) After three rows Qty total is 4420

6) so on forout row I will take only 580 * 800

7) so now I have my Total purchase value for 5000 MT and it I divide it by 5000 I will get the Purchase Avergae