title: Aggregation Operation in Kettle / Pentaho
body: <p>I'm trying to do an aggregate operation between some columns from an Excel file input. I have the following case:</p>
  
  <pre>Column 1   Column 2    Column 3
  
  X            $15           A
  X            $20           A
  Y            $1        B
  Y            $1        B
  Y            $3        C
  
  </pre>
  
  <p>And i want to achieve this aggregation operation:</p>
  
  <pre>
  Column 1    Column 2    Column 3
  
  X             $35           A
  Y             $2            B
  Y             $3            C
  
  </pre>
  
  <p>As you see, the Column 1 and 3 are the criteria for doing the aggregation operation, in this case, i want to get the sum of the column 2.</p>
  
  <p>Is there any way to do this in Pentaho Data Integration? I've tried with "Join Rows" and "Join Rows (As a cartesian product)", but, i have no results.</p>