title: Can I pass connection strings to subreports via parameters and use as a subscription?
body: <p>I am trying to get a SSRS report with a subreport to work as a subscription, but am failing.  The reports work fine when executed manually.  What I am trying to do may be too complex for subscriptions, but here is the general idea:</p>
  
  <p>My main report has within it a very simple query which builds a list of databases.  Say, for example, I have 10 databases in total.  My main report queries all 10 databases and returns the actual database name for each one. Then, the main report passes each database name as a parameter to my subreport.</p>
  
  <p>The subreport uses each database name in its connection string via the following: <code>="Data Source=sql-server-name;" &amp; "Initial Catalog=" &amp; Parameters!ParentID.Value</code></p>
  
  <p>The problems I am having are twofold:</p>
  
  <ol>
  <li>Currently, am receiving an error in creating a subscription for my main report.  The error message I receive is <code>Subscriptions cannot be created because the credentials used to run the report are not stored, or if a linked report, the link is no longer valid.</code> I have already tried specifying each of the possible authentication methods available on the report server, including "Credentials stored securely", Windows integrated security, etc.</li>
  <li>At one point, I had a subscription created, but when the subscription attempted to run and send an email, the error message I received was: <code>The current action cannot be completed. The user data source credentials do not meet the requirements to run this report or shared dataset. Either the user data source credentials are not stored in the report server database, or the user data source is configured not to require credentials but the unattended execution account is not specified. (rsInvalidDataSourceCredentialSetting)</code>. In order to address this, I recently tried creating a "Unattended Execution Account" following the advice <a href="https://stackoverflow.com/questions/11139777/anyone-seen-this-the-user-data-source-credentials-do-not-meet-the-requirements">here</a>, but was unable to prove whether or not it worked because currently I cannot modify my subscriptions to schedule a test (due to problem #1).</li>
  </ol>
  
  <p>Can I pass connection strings to subreports via parameters and have the main report execute as a subscription? If so, how?</p>