title: update mongo array with pentaho kettle
body: <p>i need to update elements in an array, but could not find a solution. please find details below</p>
  
  <p>this is my table input:</p>
  
  <pre><code>select '123' partner_customer_id, '222' order_id, '1' quantity union all
  select '123' parner_customer_id, '333' order_id, '2' quantity
  </code></pre>
  
  <p>and this is my mongo output:</p>
  
  <pre><code>Name Mongo document path Use field name Match field for upsert Modifier operation Modifier policy
  partner_customer_id Y Y N/A Insert
  partner_customer_id Y N N/A Insert
  order_id sales[0] Y N $set Insert
  order_id sales[1] Y N $push Update
  quantity sales[0] Y N $set Insert
  quantity sales[1] Y N $push Update
  </code></pre>
  
  <p>please find below the screenshot about the mongodb output
  <a href="http://cl.ly/image/18442w163v1x" rel="nofollow">http://cl.ly/image/18442w163v1x</a></p>
  
  <p>When running the above it inserts a customer record with an two element array. (the two orders ) if running it again there will be a customer record with an 4 element array, etc.</p>
  
  <p>But i want to reach that it updates the array elements as well based on the order_id field. eg the quantity changes from 1 to 4 then it updtes the quantity, but array element remains the same only change: quantity is updted in the relevant element. It is possible to do this in pentaho?</p>
  
  <p>thanks in advance</p>