How to do a basic summation?

Grafana Dashboards
14

I figured out a messy way to do it.
First create a separate query for each data series:

from(bucket: "energy")
  |> range(start: v.timeRangeStart, stop:v.timeRangeStop)
  |> filter(fn: (r) =>
    r._measurement == "s-31" and
    r.topic == "tele/growlight-s31/SENSOR" and
    r._field == "totalwh"
  )

This by itself yields a single data series, like this:
image
Then create a reduction expression for each data series query to grab only the last value:
image
Then finally create a math expression and add all the reduction expression values together:
image
I say this is messy because for n number of data series being summed, you need 2n+1 queries/expressions, so the query page gets real cluttered. There’s also the drawback that, while it does return the sum of the latest value in each data series:
image
it returns exactly one value, so the usual trendline in the stat visualization is missing.
image
If anyone knows a better way to do this, please let me know, but I’m marking this as the solution for now.

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