When you are editing a query, you can also click on 'Test' to test the results. The query is a MYSQL query. If can get complex when you combine databases, but when you use only one database like storage.array is very simple. For cdot, all the databases begin with cmstorage. and for 7mode they begin with storage.
For example, if you do a SELECT * FROM storage.aggregate , and the click on Test, you will see all the storage.aggregate database and fields. If you wanted only the name, then you could need SELECT name from storage.aggregate , but sometimes you can also need free space left ( for example ) , and then order by that space in descending form.
The error you mention could be that you needed the name or ip only and something else is appearing in that field.
Try to do a SELECT name from storage.array , preview there, and if it does not work, try a SELECT ip from storage.array .
Of course, the fields you can choose can be then searched with SELECT * from storage.array , and also you could troubleshoot by leaving a string in the user input ( no dropdown sql query ) and then trying to see what does it want manually.
Hope that helps.