i try to make the running sum of quantity using query
with a expected output
ID | Date_in | Date_out | Quantity_in | Quantity_out | Quantity_Run_Sum
in01 |17/2/2011| | 300 | 0 | 300
in02 |17/2/2011| | 400 | 0 | 700
Out01 | |20/2/2011 | 0 | 100 | 600
Out02 | |20/2/2011 | 0 | 100 | 500
in03 |21/2/2011| | 10 | 0 | 510
Out04 | |21/2/2011 | 0 | 10 | 500
but what i get is
ID | Date_in | Date_out | Quantity_in | Quantity_out | Quantity_Run_Sum
in01 |17/2/2011| | 300 | 0 | 300
in02 |17/2/2011| | 400 | 0 | 700
Out01 | |20/2/2011 | 0 | 100 | 610
Out02 | |20/2/2011 | 0 | 100 | 510
in03 |21/2/2011| | 10 | 0 | 710
Out04 | |21/2/2011 | 0 | 10 | 500