No option to Remove Tag Filter if Where query ill-formed on InfluxDB source

Using Grafana v5.1.4 to query an InfluxDB v1.5 source I have a few tags I want to filter by. My location tag filters against a string nicely and provides the ability to remove the filter after it has been chosen from the drop downs.

Choosing my serial tag populates the drop down with appropriate selections just as the strings were sent to InfluxDB via node-red. However, Grafana provides an error parsing query suggesting it expected identifier, string, number, bool instead of the actual string it provided in the drop down. I’m open to suggestions on fixing my query as I am clearly doing something wrong here. It seems likely a function of the method I’m using to send the tags to the db through the node-red influxdb batch uploader:
serial: global.get(“invSerial”) }

While I realize this is a query or db error, and one I need to figure out, the result of my ignorance is that the option to remove tag filter is not available from within the Grafana interface. It seems to me that the interface could stand to fail more gracefully when faced by noobs like myself :blush:


This query succeeds:
SELECT mean("power") FROM "autogen"."inverter" WHERE ("location" = 'warehouse')

Whereas this query, despite the string being populated by the drop down selector, fails with the parsing error:
SELECT mean("power") FROM "autogen"."inverter" WHERE ("serial" = 'MIBB007236')