Missing added field when using to() function - though query includes all fields

Fluxlang
1

Hello.
Maybe you can help me with this. I am collecting my PV data.
In the query (manually) all is correct, all fields exist, including the “panel” field:

import “timezone”
import “date”
option location = timezone.location(name: “Europe/Berlin”)

from(bucket: “s13mppt”)
|> range(
start: date.add(d: -1d, to: date.truncate(t: now(), unit: 1d)),
stop: date.truncate(t: now(), unit: 1d),
)
|> filter(fn: (r) => r[“_measurement”] == “Leistung”)
|> filter(fn: (r) => r[“MPPT”] == “MPPT1”)
|> filter(fn: (r) => r[“_field”] == “mppt1total”)
|> aggregateWindow(every: 1d, fn: max, createEmpty: false, timeSrc: “_start”)
|> map(fn: (r) => ({r with panel: r._value/2.58}))
|> drop(columns: [“_start”, “_stop”])

> yield(name: “test”)
![image

When I do an export in a table with a scheduled task with the identical query including at the end:
|> to(bucket: “s13test”, org: “synology”)

in the resulting data in bucket s13test there is no field “panel”.

image
image1736×175 21.3 KB

Up to now I always had correct exports, but this time I added a field and maybe I overlook something. Thank you for any hint.

2

Here is the first screenshot with correct query:

image
image1767×179 18.9 KB

3

The issue is essentially that the new column panel is a float/double, so your row now has two fields in rather than one.

to() expects long (i.e. one field per row) rather than wide tables, so each of the rows can only contain one field value - everything else needs to be a string. panel gets ignored because it’s the wrong type.

As you’re calculating the value from the the existing value, I assume that you don’t want it to be treated as a tag but as a new field?

If so, give this a try

import “timezone”
import “date”
option location = timezone.location(name: “Europe/Berlin”)

// Query the data out
data = from(bucket: “s13mppt”)
|> range(
start: date.add(d: -1d, to: date.truncate(t: now(), unit: 1d)),
stop: date.truncate(t: now(), unit: 1d),
)
|> filter(fn: (r) => r[“_measurement”] == “Leistung”)
|> filter(fn: (r) => r[“MPPT”] == “MPPT1”)
|> filter(fn: (r) => r[“_field”] == “mppt1total”)
|> aggregateWindow(every: 1d, fn: max, createEmpty: false, timeSrc: “_start”)
|> drop(columns: [“_start”, “_stop”])

// Create the new field/value and write into the dest bucket
data
|> map(fn: (r) => ({r with 
   _field: "panel",
   _value: r._value/2.58
}))
|> to(bucket: “s13test”, org: “synology”)


// Assuming you wanted a copy of the original data in there too
data
|> to(bucket: “s13test”, org: “synology”)

Just for completeness, if you did want it to be a tag rather than a field value, converting it to a string should do the job:

|> map(fn: (r) => ({r with panel: string(v: r._value/2.58)}))