Grafana showing 'No data points' for InfluxDB data

I am new to grafana and influxdb. My need is to show a simple time series graph on grafana. To obtain a sample time-series data, I followed the instructions given in the link

I am able to query this database in InfluxDB and I am able to see the data as well. However when I connect to this DB from Grafana, I see “No data points” on the graph.

I confirm that I have tested the connection to InfluxDB and it is working fine. Following is the query from the query inspector

SELECT mean(“degrees”) FROM “h2o_temperature” WHERE time >= now() - 6h GROUP BY time(1s) fill(null)"

Could anyone help me understand what I should do to get the graph show the time series? Thanks.