datacolumn or dataview binding problem

[bilalso]

Hi,

I have a datatable that has different columns such as
ItemID
OrderID
OrderSize
OrderPrice

Only at the startup I load these values from the database and
afterwards I add new rows in the datatable from the data I receive
through sockets.
I display the data in various arrangements of rows and columns in
different datagrids, but the source of all the datagrids is this
datatable.
I have created dataviews from the datatable which are bound to
different datagrids to display these values in different arrangments of
rows and columns to different user.
Now there are several other values I need to display which are based on
the columns I mentioned above. For example I need to display

ItemID OrderID Order_size
SUM_OrderSize_by_ItemID

1 1 10
15

1 2 5
15

2 4 8
8

w here 15 is calculated by summing up all the ordersizes for the itemID
of that row, which in this case is 1.

Is this possible ?? Is this possible by creating a datacolumn
expression ?? or I can do it using DataViews.RowFilter to any such
property ??

Thanks,

 

[bilalso]

Formatting was'nt properly done in the previous post, This is how the
example should look like.

ItemID OrderID Order_size SUM_OrderSize_by_ItemID

1 1 10 15

1 2 5 15

2 4 8 8