This week's book giveaway is in the Servlets forum. We're giving away four copies of Murach's Java Servlets and JSP and have Joel Murach on-line! See this thread for details.

I need some help about ireport. I have two column. The first column contains the type of a transaction (PURCHASE, TOPUP, STORNO....). The second column contains a number which is the amount of the transaction (1000, 500...). I need the sum of every transaction type (PURCHASE SUM, TOPUP SUM, STORNO SUM....).
So I need as much sums as much different transaction types the column has.

I can get the sum of every transaction, but I can't get the sums separately.