如何在 Grafana / InfluxDB 中创建百分比/比率列？

Question

我有有关写入 InfluxDB 的错误的数据（示例已简化）。

 time   | error   | some_unique_data
--------|---------|--------------------
 <time> | hello 1 | some unique data...
 <time> | hello 2 | some unique data...
 <time> | hello 2 | some unique data...
 <time> | hello 3 | some unique data...

我可以编写以下查询来查看 Grafana 中最常见错误的排序列表：

SELECT COUNT("some_unique_data") FROM "my_measument" WHERE $timeFilter GROUP BY error

这使：

| error   | count
|---------|-------
| hello 2 | 2
| hello 1 | 1
| hello 3 | 1

我缺少的是向我显示每个错误的影响的列，如下所示：

| error   | count | impact
|---------|----------------
| hello 2 | 2     | 50%
| hello 1 | 1     | 25%
| hello 3 | 1     | 25%

我应该在查询中添加什么才能使该impact字段正常工作？

Answer 1

Here is a useful answer, but unfortunately it doesn't solve your issue.

In your example:

| error   | count
|---------|-------
| hello 2 | 2
| hello 1 | 1
| hello 3 | 1

you've used GROUP BY "error" to get the count of each error, so once you did this you don't have access to the full count anymore, so you must do it before GROUP BY.

You can't do:

SELECT COUNT(*) AS full_count, "some_unique_data" FROM "my_measument" WHERE $timeFilter

in order to get the full number of records because you can't use SELECT COUNT(), "field_name" FROM ...

So, getting the full count before doing GROUP BY isn't possible.

Well, let's try something else:

SELECT "fields_count" / SUM("fields_count") AS not_able_to_use_SUM_with_field , "error" FROM ( 
    SELECT COUNT("some_unique_data") AS fields_count AS fields_sum FROM "my_measument" WHERE $timeFilter GROUP BY "error"
)

This previous query isn't working apparently. Then what to do?

Sorry, You can do Nothing :/

Here is another link to the documentation.