title: Trying to populate dropdown using the result of mongo query
body: <p>I have created a grafana application. I am using the variables function and within that, I have the option to return a query which populates the dropdown. I have tested the query in a normal table panel and it returns the correct values. Using this in the query in the variables section doesn't work.</p>
  
  <p>Additionally and potentially more importantly, since mongo is not used by default as a datasource for Grafana, I have to install a plugin which is linked: </p>
  
  <p><a href="https://github.com/JamesOsgood/mongodb-grafana" rel="nofollow noreferrer">https://github.com/JamesOsgood/mongodb-grafana</a></p>
  
  <p>What would be the best way to achieve what I am doing? Any help appreciated. Thanks!</p>