title: powerapps: populate drop down list from another datasource
body: <p>I stumbled across Microsoft PowerApps earlier, and though I would have a play with it. I have connected to my SQL Server, and created a template for browsing, viewing and editing a basic application. Now in my database I have the following relationship:</p>
  
  <p><a href="https://i.stack.imgur.com/7WSph.png" rel="nofollow"><img src="https://i.stack.imgur.com/7WSph.png" alt="enter image description here"></a></p>
  
  <p>On the add/edit screen this asks the user to enter the "<code>CustomerID</code>". <strong><em>I want to be able to use a drop down menu to search the list of customers</em></strong>.</p>
  
  <p>So far I have:</p>
  
  <ol>
  <li>Added an additional Datasorce to my table "Customers"</li>
  <li>Changed the control from a text box to a drop down menu</li>
  </ol>
  
  <p><a href="https://i.stack.imgur.com/UMlY9.png" rel="nofollow"><img src="https://i.stack.imgur.com/UMlY9.png" alt="enter image description here"></a></p>
  
  <p>it is at this stage I am stuck and unsure of how to progress further. Currently when debugging, the list shows nothing, nor appears to be searchable. </p>