问题

以下是翻译好的部分：

The visualization templates I have for creating a dashboard in Chronograf always expect numbers (except table). How can I make it so that I get text instead of a number in certain cases?

在Chronograf中，我用于创建仪表板的可视化模板始终期望数字（除了表格）。如何使某些情况下获得文本而不是数字呢？

For instance:

例如：

The logic I want to implement is:

我想要实现的逻辑是：

if result eq 0 then return "Idle" else return value

如果结果等于0，则返回"Idle"，否则返回值

That's my Influx-Query, which results in 0.

这是我的Influx查询，其结果为0。

SELECT last("DischargingBattery") AS "DischargingBattery" FROM "wallbox"."autogen"."battery"

从"wallbox"."autogen"."battery"中选择最后一个"DischargingBattery"作为"DischargingBattery"

This ends up with this result on the Dashboard:

这在仪表板上显示为以下结果：

当此查询结果为0时，我希望在我的仪表板上看到字符串"Idle"，而不是数字零。

That is what I would like to achieve:

这是我想要实现的目标：

if result eq 0 then return "Idle" else return value

SELECT last("DischargingBattery") AS "DischargingBattery" FROM "wallbox"."autogen"."battery"

答案1

得分: 3

使用InfluxQL可能无法帮助您在这方面。

您可以尝试Flux，这是InfluxData的新功能数据脚本语言，专为查询、分析和处理数据而设计。
查看Flux文档：https://docs.influxdata.com/flux/v0.x/

Map函数：https://docs.influxdata.com/flux/v0.x/stdlib/universe/map

步骤1：通过此文档在InfluxDB 1.X中启用Flux：https://docs.influxdata.com/influxdb/v1.8/flux/installation/
步骤2：将您的查询更改为以下内容：

from(bucket: "wallbox/autogen")
|> range(start: "2022-02-22T20:22:02Z", stop: now())
|> filter(fn: (r) => r._measurement == "battery")
|> filter(fn: (r) => r._field == "DischargingBattery")
|> last()
|> map(fn: (r) => ({r with _value: if r._value > 0 then "Idle" else _value}))

from(bucket: "wallbox/autogen")
|> range(start: "2022-02-22T20:22:02Z", stop: now())
|> filter(fn: (r) => r._measurement == "battery")
|> filter(fn: (r) => r._field == "DischargingBattery")
|> last()
|> map(fn: (r) => ({r with _value: if r._value > 0 then "Idle" else _value}))

答案2

得分: 0

这是我用来将0和1转换为"night"和"day"的方法。toString()对我来说是解决方案，它不喜欢在映射中使用整数类型的条件。我还需要在“value options -> Fields”下选择“Tarif”字段，这也将解决您在面板中关于字符串与整数的其他问题。

from(bucket: "p1_meter")
  |> range(start: -15m)
  |> filter(fn: (r) =>
    r._measurement == "P1_measurements" and
    r._field == "tarif"
  )
  |> last()
  |> toString()
  |> map(fn: (r) => ({r with _value: if r._value == "0" then "night" else "day" }))

您也可以将这个方法用于您的类似情况：

...
|> last()
|> toString()
|> map(fn: (r) => ({r with _value: if r._value == "0" then "IDLE" else _value }))

panel value options

<details>
<summary>英文:</summary>

this is what I used to transform 0 and 1 to &quot;night&quot; and &quot;day&quot;
The toString() was the solution for me, it didn&#39;t like to use Integer type for the condition in the map.
I needed also to select under &#39;value options -&gt; Fields&#39; the &#39;Tarif&#39; field,  which will also solve your other issue about string vs int in the panel.

        from(bucket: &quot;p1_meter&quot;)
      |&gt; range(start: -15m)
      |&gt; filter(fn: (r) =&gt;
        r._measurement == &quot;P1_measurements&quot; and
        r._field == &quot;tarif&quot;
      )
      |&gt; last()
      |&gt; toString()
      |&gt; map(fn: (r) =&gt; ({r with _value: if r._value == &quot;0&quot; then &quot;night&quot; else &quot;day&quot; }))

You could use this to your analogy as well:

    ...
    |&gt; last()
    |&gt; toString()
    |&gt; map(fn: (r) =&gt; ({r with _value: if r._value == &quot;0&quot; then &quot;IDLE&quot; else _value }))

[panel value options][1]


  [1]: https://i.stack.imgur.com/fo2iS.png

</details>