title: Pentaho step - Use SQL functions to add a column in data before dumping it int DB
body: <p>I am fairly new to Pentaho, and while working on it, I have stumbled across a problem. Below is how my flow is:</p>
  
  <ol>
  <li>Read input from a file. Let's say this has 5 columns.</li>
  <li>Make some modifications to existing columns. (Filter, modify and all).</li>
  <li>Add a new column, which will be equal to an SQL function of the current row data. Example, it can be sum(id, id+1)</li>
  <li>Dump to the database.</li>
  </ol>
  
  <p>Step 1,2, 4 are already in place and are working fine. It's Step 3 where I am stuck. I've tried to execute SQL, but that is only for Modifying DDL and doesn't return data. Table input needs data to be in a table already, which isn't the case with me.</p>
  
  <p>I have a workaround, that I can enter all rows in DB, and then fire an update query, but I was hoping if there is a better way to do this.</p>