Grafana - InfluxDB 2 - Label/Alias data

I am in the processing of migrating my panels from using the SQL syntax (from InfluxDB version 1.X) to the new influx syntax (InfluxDB version 2).

There is an issue with the labels of the data. It includes the attributes that I used to filter it. For example, if I select data from a range that contains 2 days, it splits the data up. See the screenshot below:

This completely messes the chart up. The base code looks like this:

from(bucket: "main")
  |> range(start: v.timeRangeStart, stop:v.timeRangeStop)
  |> filter(fn: (r) =>
      r._measurement == "POWER" and
      r._field == "value" and
      r.device == "living_room"
  )
  |> aggregateWindow(every: v.windowPeriod, fn: sum)

It should obviously just be "POWER" and "CURRENT".

I tried a dozen of different approaches, but cannot come up with a working solution.

For example, if I do:

from(bucket: "main")
  |> range(start: v.timeRangeStart, stop:v.timeRangeStop)
  |> filter(fn: (r) =>
      r._measurement == "POWER" and
      r._field == "value" and
      r.device == "living_room"
  )
  |> aggregateWindow(every: v.windowPeriod, fn: sum)
  |> map(fn: (r) => ({ POWER: r._value }))

it says "Data does not have a time field".

I also tried using

from(bucket: "main")
  |> range(start: v.timeRangeStart, stop:v.timeRangeStop)
  |> filter(fn: (r) =>
      r._measurement == "POWER" and
      r._field == "value" and
      r.device == "living_room"
  )
  |> aggregateWindow(every: v.windowPeriod, fn: sum)
  |> yield(name: "POWER")

that does not work either. I tried many other things without success.

How can I fix this?

After hours of trial and error, I was able to produce a working solution. I imagine that other users may stumble upon the same issue, I will therefore not delete the question and instead provide my solution.

I basically had to map the required fields and tags and assign the desired label, instead of just mapping the value that should be displayed (because then the date/time data is missing).

The solution looks like this:

from(bucket: "main")
  |> range(start: v.timeRangeStart, stop:v.timeRangeStop)
  |> filter(fn: (r) =>
      r._measurement == "POWER" and
      r._field == "value" and
      r.device == "living_room"
      )
  |> aggregateWindow(every: v.windowPeriod, fn: max)
  |> map(fn: (r) => ({ _value:r._value, _time:r._time, _field:"Power (W)" }))

Power (W) is the label/alias that is going to be used.

I wish that Influx would provide an easier way to alias the desired field. The current approach is not very intuitive.