Feels like a straightfoward case, but I haven’t been able to manage the query.
I have two _fields that contain values for two pumps that we’re monitoring. They both belong to the same station. I’m trying to make a query that provides a combined output table with three columns (for output to Grafana), like so:
Time Pump Value 2021-03-22T14:14:06.340Z Pump1 71.15999603271484 2021-03-22T14:14:06.340Z Pump2 164.20999145507812 2021-03-22T14:14:06.340Z Pump1 73.70999145507812
Time Pump1 Pump2 2021-03-22T14:14:06.340Z 71.15999603271484 2021-03-22T14:14:06.340Z 164.20999145507812 2021-03-22T14:14:06.340Z 73.70999145507812
With separate queries I get the results for each pump just fine, but I can’t seem to combine them into a single table. When I do a union like below, I get both separate tables in one view (and can switch between them in Grafana), but I don’t get a single table.
Pump1 = from(bucket: "StationData") |> range(start: -3h) |> filter(fn: (r) => r._measurement == "plc" and r._field == "Pump1" and r.host == "Station1" ) Pump2 = from(bucket: "StationData") |> range(start: -3h) |> filter(fn: (r) => r._measurement == "plc" and r._field == "Pump2" and r.host == "Station1" ) union(tables: [Pump1, Pump2])
Using ‘join’ I can get the results together in a single table, but, as one would expect in a join, I get a lot of duplicate fields
It feels like I want to do something like convert the field-names for Pump1 and Pump2 to both be ‘Pump’ and then do the union. So I’ve been looking at the ‘Rename’ function, but without much success so far.
Anyone can give me a push in the right direction?