Handle zero divide failed in map fn

InfluxDB 2
1

InfluxDB v2.6.1 (git: 9dcf880fe0) build_date: 2022-12-29T15:53:07Z

Hi~
I found something strange when I use conditional expressions to handle zero divide。
When I ran below query without divide operation，the result _value returned as expected（0->-1 or the origin value）

from(bucket: "cams_http_detect")
  |> range(start: 2023-02-06T19:52:18.309Z, stop: 2023-02-07T07:52:18.309Z)
  |> filter(fn: (r) => r["name"] == "system1")
  |> filter(fn: (r) => r["_measurement"] == "http_metric" )
  |> filter(fn: (r) => r["_field"] == "response_length" or r["_field"] == "response_time")
  |> pivot(rowKey:["_time"], columnKey: ["_field"], valueColumn: "_value")
  |> map(
        fn: (r) => ({
            _start:r._start,
            _stop:r._stop,
            _time: r._time,
            node:r.node,
            access_url:r.access_url,
            _measurement: r._measurement,
            _field: "download_speed",
            _value: if r.response_time == 0  then -1 else r.response_time,
        }),
    )
    |>drop(columns: ["response_length", "response_time"])
    |>group(columns:["_field","_start","_stop","_measurement","access_url","node"])

image
image866×668 10.9 KB

But after adding divide operation，the query run failed with zero divide error。

from(bucket: "cams_http_detect")
  |> range(start: 2023-02-06T19:52:18.309Z, stop: 2023-02-07T07:52:18.309Z)
  |> filter(fn: (r) => r["name"] == "system1")
  |> filter(fn: (r) => r["_measurement"] == "http_metric" )
  |> filter(fn: (r) => r["_field"] == "response_length" or r["_field"] == "response_time")
  |> pivot(rowKey:["_time"], columnKey: ["_field"], valueColumn: "_value")
  |> map(
        fn: (r) => ({
            _start:r._start,
            _stop:r._stop,
            _time: r._time,
            node:r.node,
            access_url:r.access_url,
            _measurement: r._measurement,
            _field: "download_speed",
            _value: if r.response_time == 0 then -1 else r.response_length/r.response_time,
        }),
    )
    |>drop(columns: ["response_length", "response_time"])|>group(columns:["_field","_start","_stop","_measurement","access_url","node"])

Error: failed to execute query: 400 Bad Request: runtime error: cannot divide by zero

So where is the problem in my query？
Thanks in advance.