Newbie with Pentaho Reporting and looking for some advice with what I am sure is a very simple question.

In my report I am pulling in data from a pdi transformation, its just a list of prices. There are 26 items in the list and each has a price value which is of type [double]. All I want to do is have a single field which contains the sum total for all the values. I am able to add a numeric-field, point it to the data source and then, using the aggregation-type select SUM; which I thought would do the trick. It works but I get a value for every item in the list. In my case I get a list of 26 instances of 237 (which IS the total).

Q - How to get a single value of 237 not an instance of the value for every item in the list?

I must be missing something very simple, I'm sure.