title: deleting rows in azure data flow
body: <p>I am trying to clean a data frame In azure data flow using alter row operation. I  have created a blob link service with CSV file (5 columns). Then created a data flow as follows: Please refer to the image attached.</p>
  
  <p>enter image description here 
  <a href="https://i.stack.imgur.com/vOILh.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/vOILh.png" alt="enter image description here"></a></p>
  
  <p><a href="https://i.stack.imgur.com/bOXXd.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/bOXXd.png" alt="enter image description here"></a></p>
  
  <p>As you can see in the third image, alterrow still contains zero columns, not picking up columns from the source file. Can anyone tell me why this is happening?</p>
  
  <p><a href="https://i.stack.imgur.com/yKHEg.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/yKHEg.png" alt="enter image description here"></a></p>