Filter expression - how to use data set column

dyeager

Good morning,

I've got a data set that looks like this:

Item / Amount
item1 / 100
item2 / 50
item1 / 120
item1 / 30
item2 / 20

I want to add a computed column that to my data set that simply gives me the sum of all of each item, so the result would be:

Item / Amount / ItemTotal
item1 / 100 / 250
item2 / 50 / 70
item1 / 120 / 250
item1 / 30 / 250
item2 / 20 / 70

I thought this would be reasonably simple using an aggregation plus a filter expression, but there doesn't seem to be a way to dynamically assign the filter - for example I know if I simply set the filter to row["Item"] == "item1" I will get my total for item1, but I don't know how to dynamically do this. Trying to store the value of the current row in a filter expression doesn't seem to work - I've tried something like:

var currentval = row["Item"];
row["Item"] == currentval;

The problem is it gives me the overall total because that is always true - any idea on how to do what I want here? Thanks a ton!

mwilliams

Hi dyeager,

Are you not wanting to group these values in a table and just supply the sum? You want them to stay in their order and have the sum for the group next to them? Is this the case? Let me know.