title: appending to a file in azure data lake using data factory
body: <p>I am running into issues while appending data to a file in azure data lake, using data factory.
  I am trying to get data from MS Graph API and I am able to get the data and copy it for Single API calls where I push the response to the data lake, using &quot;Copy Data&quot; functionality, but if I want to do multiple calls where I get a response, and then append these responses to a single file, I am not sure how to do that. I don't think the &quot;Copy data&quot; activity is the right action for it.</p>
  <p><strong>One Example:
  API to get all groups in tenant:</strong></p>
  <p><a href="https://graph.microsoft.com/v1.0/Groups/" rel="nofollow noreferrer">https://graph.microsoft.com/v1.0/Groups/</a></p>
  <p><strong>API to get all members associated with a group:</strong></p>
  <p><a href="https://graph.microsoft.com/v1.0/groups/%22GroupID%22/owners" rel="nofollow noreferrer">https://graph.microsoft.com/v1.0/groups/&quot;GroupID&quot;/owners</a></p>
  <p><strong>&quot;Group ID&quot; comes from the top API call.</strong>**</p>
  <p>I am able to build a loop and do the calls correctly.
  It is just appending the results of the second call where I am at a loss. I don't think creating a new file for each group would be the right approach.</p>