title: Yii2 : how to use distinct , groupby , sum and where conditions
body: <p>I want execute below query in using <code>Yii2</code> syntax selection query,</p>
  
  <pre><code>select distinct pfs_id, unitprice, sum(qty)
  from order_items
  where order_id= id
  and item_farm_id = id
  group By pfs_id
  </code></pre>
  
  <p>I tried several times but still not getting luck,</p>
  
  <p>Please any one help.</p>