It is possible to use insight visual to display some text if query result contains no data.
The easiest way to do it is
- click “Add Insight” in the top left corner
- select Unique Values from the list of insights and click “Select” to close the dialog.
- add a field to the “Category” field well
- select “Customize narrative” option on the visual to display your own message and change the entire expression to something like the image below
